Obesity: a disease of the brain?

Kullmann et al. A short-term, high-caloric diet has prolonged effects on brain insulin action in men. Nature Metabolism, February 2025.

Obesity is a growing disease associated with serious illnesses like diabetes, heart disease, and cancer. The World Health Organization has labeled obesity an epidemic, affecting over a billion people worldwide. Obesity is defined by a body mass index (BMI) of 30 or higher, often attributed to poor diet and lack of exercise. However, the underlying biological mechanisms are more complex, particularly regarding the brain’s sensitivity to insulin. A recent study found that even short-term consumption of highly processed foods, such as chocolate bars and potato chips, can significantly alter brain function in healthy individuals, potentially triggering obesity and type 2 diabetes. Normally, insulin suppresses appetite, but in obese individuals, it fails to regulate eating behavior, leading to insulin resistance. The study also revealed that after just five days of high-calorie intake, the brain’s insulin sensitivity in healthy individuals decreased similarly to that observed in obese people. This effect persisted even after returning to a balanced diet for a week. The study involved 29 healthy-weight male participants divided into two groups. One group consumed an additional 1,500 kcal per day from processed snacks for five days, while the control group maintained its regular diet. MRI scans showed increased liver fat in the high-calorie group and a significant reduction in brain insulin sensitivity, which remained even after returning to normal eating habits. Scientists emphasize that the brain’s insulin response adapts to short-term dietary changes before weight gain occurs, highlighting the need for further research into obesity’s neurological factors.

Inheritance of Trauma Through Genes

Mulligan et al. Epigenetic signatures of intergenerational exposure to violence in three generations of Syrian refugees, Scientific Reports, February 2025.

In 1982, the Syrian government carried out a brutal siege in Hama, killing tens of thousands. Beyond the historical and political repercussions, the violence left a hidden impact—one embedded in the genes of Syrian families. A groundbreaking study has now shown that the trauma experienced by pregnant women during the siege has left genetic marks on their grandchildren, supporting the idea that stress and violence can have long-term biological effects. This study explored how trauma is passed across generations through epigenetics, a process in which chemical markers alter gene expression in response to stress. While animal studies have demonstrated the inheritance of stress-induced epigenetic changes, proving it in humans has been challenging. To investigate, researchers studied three generations of Syrian refugees, comparing families who survived the Hama massacre, those affected by the recent civil war, and a control group who immigrated to Jordan before 1980. They collected DNA samples from 138 individuals across 48 families, focusing on mothers and grandmothers who were pregnant during violent events and their children. They discovered 14 specific areas in the genome of the grandchildren of Hama survivors that bore stress-induced modifications. Additionally, 21 epigenetic sites were altered in those who directly experienced violence. Another finding showed that individuals exposed to violence in the womb exhibited signs of accelerated biological aging, potentially increasing their vulnerability to age-related diseases. While the long-term effects of these modifications remain uncertain, past research suggests links between stress-induced epigenetic changes and health conditions like diabetes and obesity. A well-known study on Dutch famine survivors found similar genetic imprints affecting their offspring’s metabolism. Beyond scientific discovery, the study highlights the resilience of affected families. Despite enduring immense hardship, they continue to build meaningful lives. These findings are likely relevant beyond war zones, shedding light on how various forms of violence—domestic abuse and gun violence—can have lasting biological consequences.

The New Hypothesis for Mars’ Red Color Suggests a Once-Habitable Past

Valantinas et al. Detection of ferrihydrite in Martian red dust records ancient cold and wet conditions on Mars. Nature Communications, February 2025.

Mars’ iconic red color has long fascinated scientists, and a new study suggests that the water-rich iron mineral ferrihydrite may be responsible for the planet’s reddish hue. A recent work challenges the prevailing theory that hematite, a dry, rust-like mineral, is the primary cause. Ferrihydrite forms in water-rich environments, unlike hematite, which typically develops in drier conditions. This discovery supports the idea that Mars once had liquid water and a more habitable environment. The findings suggest that Mars transitioned from a wetter past to its current cold and arid state billions of years ago. To reach their conclusion, researchers analyzed data from multiple Mars missions, including NASA’s Mars Reconnaissance Orbiter and rovers like Curiosity and Opportunity. They combined spectral observations from orbiters with ground-level measurements and conducted lab simulations, recreating Martian dust to study how light interacts with ferrihydrite. By grinding minerals to submicron sizes—1/100th the width of a human hair—the team replicated the fine Martian dust, confirming that its light reflection closely matches observations from Mars. This discovery opens new possibilities for understanding Mars’ ancient climate and habitability. Since ferrihydrite forms in the presence of water and oxygen, its widespread presence suggests Mars had conditions far different from its current dry and cold landscape. The findings may also help answer fundamental questions about whether Mars once supported life. However, final confirmation awaits the return of Martian samples, currently being collected by the Perseverance rover. These samples could definitively determine whether ferrihydrite is the key to Mars’ red dust, unlocking more secrets about the planet’s history.

Cell-based therapy may be used to treat obesity and diabetes

Wang CH et al. CRISPR-engineered human brown-like adipocytes prevent diet-induced obesity and ameliorate metabolic syndrome in mice. Science Translational Medicine, August 2020.

Obesity is the main cause of type 2 diabetes and related chronic diseases that will be the cause of death for more people across the globe this year than Covid-19. Scientists recently have developed a proof of concept for a novel cell-based therapy against obesity. The potential therapy for obesity would transplant HUMBLE (human brown-like) fat cells, or human white fat cells that have been genetically modified to become similar to heat-generating brown fat cells.

Brown fat cells burn energy, instead of storing energy, as white fat cells do. In this process, brown fat can lower excessive levels of glucose and lipids in the blood that are linked to metabolic diseases such as diabetes. However, people who are overweight or obese tend to have less of this beneficial brown fat. The transformed HUMBLE cells are expected to overcome this problem.

The research team first generated HUMBLE cells from white preadipocytes and then used a variant of the CRISPR-Cas9 genome editing system to stimulate the expression of a gene called UCP1, which can transform white preadipocytes into fat brown cells. When these HUMBLE cells were transplanted into mice, they then remarkably functioned as the mice’s own brown fat cells. On a high-fat diet, the mice that received HUMBLE cells showed a much higher sensitivity to insulin and the ability to eliminate glucose from the blood than the mice in the control group. They also gained less weight. These results from animal studies are very encouraging for researchers. The hope is to generate HUMBLE brown cells for individual patients soon. Such a procedure would involve taking a small number of white preadipocytes from a patient, isolating the precursor cells, modifying these cells to stimulate UCP1 expression, and then re-transplanting the resulting HUMBLE cells to the patient. However, one foreseeable challenge is that this individualized approach can be very complicated and costly. An alternative solution could be to use unadapted cells, which would then be encapsulated with biomaterials that protect the cells from being rejected by the patient’s immune system.

The other option would be to apply gene therapy approaches that directly express the UCP1 gene in white fat progenitor cells in the body so that those cells acquire HUMBLE-like properties. Employing cell-based, or gene, therapies to treat obesity or diabetes used to be science fiction. Now scientific advances, such as CRISPR gene-editing technologies, will help us to improve the metabolism, body weight, quality of life and overall health of people with obesity and diabetes.

Even fake smiling can trick the brain to be positive

Ramos FM et al. Your Face and Moves Seem Happier When I Smile. Experimental Psychology, May 2020

Can a smile truly make everything better? Is there a scientific backing to this claim? A new study shows that even if you do not feel like smiling, faking one can have positive impacts. These findings could not be more timely with the world in crisis amid the Covid-19 pandemic, which is causing disturbing spikes in anxiety and depression cases globally. The study examined participants that held a pen between their teeth, forcing their faces to use the same muscles as a smile. The results showed that facial muscular activity not only alters the recognition of facial expressions but also bodily expressions, with both generating more positive emotions. Forcefully practicing smiling stimulates the amygdala, the emotional center of the brain, which releases neurotransmitters to encourage an emotionally positive state. For mental health, this study has interesting implications. If we can trick our brains into perceiving stimuli as “happy,” then we can potentially use this mechanism to help boost our mental health. These findings suggest that there is a strong link between action and perception. Perceptual and motor systems work together when we emotionally process stimuli. A “fake it ’til you make it” approach could be more realistic than people think.

FOMO impacts people of all ages

Barry CT et al. Fear of missing out (FoMO): A generational phenomenon or an individual difference? Journal of Social and Personal Relationships, August 2020.

In the last few years, the phenomenon of FOMO (Fear of Missing Out), has afflicted many of us at one point or another. In the age of social media, we may find ourselves making comparisons to our friends, family, or even celebrities. What others have, or what they are doing that we are not, may make us feel negatively about ourselves. This can lead to anxiety, sadness, jealousy, or anger. A new study showed that FOMO, once thought to be a teenager or young adult problem, can actually have an impact on anyone irrespective of their age.

Scientists conducted a survey of more than 400 people across the United States from ages 14 to 47 and asked a range of questions related to self-perception, life satisfaction, and social media use. Experts were expecting FOMO to be higher among younger groups since teens experience so much social development in such a short space of time, but the results showed a more uniform distribution across all ages. Moreover, they suspected social media to play a large factor in FOMO but quickly found that it was not a good predictor of the condition. For instance, two people with the same social media engagement may be affected quite differently: one might feel bad seeing their friend’s activities while the other might find it upsetting. Instead, social media was found to amplify those anxieties in people that already felt as though they were missing out. Finally, it was neither their age nor social media usage but rather self-perception that shaped to what degree FOMO affected the participants Researchers say that loneliness, low self-esteem, and low self-compassion may substantially contribute to feelings of anxiety. The study concludes that one major solution to FOMO-driven anxiety would be limiting your social media usage or even cutting it off for a time. Additionally, reaching out to professionals to get support to address negative self-perceptions, perhaps by contextualizing “faults” or “flaws” as challenges to overcome.

Life is in the center of existence, and food is in the center of life. All living things are in pursuit of their sustenance to continue their lives. Failing this pursuit means the end of it all. Yet, it is not only the lack or scarcity of food, but also its abuse that is a major cause for disorders. Consuming food without any criteria of lawfulness, or with no heed to virtues like contentedness or gratitude, but with greed and wastefulness, leads to many health problems – mental and physical – at both individual and societal levels. Among these problems are many notorious eating disorders such as obesity, anorexia, and bulimia nervosa. Illnesses that relate to overeating, such as obesity, are now beginning to be considered as food addictions, even as a type of substance abuse, in some medical literature [1].

One serious consequence of eating and food addictions is a clinical condition that is called “metabolic syndrome” (MetS). Characterized by multiple cardiovascular disease risk factors such as obesity and high blood pressure, this syndrome has been recognized as a crucial public health problem worldwide. Characteristics such as geography, race, age and gender are influential in the frequency of the disease, which spreads daily as a pandemic that affects approximately 20-30% of the global adult population [2]. Among US adults aged 18 years or older, the prevalence of metabolic syndrome rose by more than 35% from 1988–1994 to 2007–2012, increasing from 25.3% to 34.2% [3].

First described by Dr. Gerald Reaven, MD, in 1988, metabolic syndrome is also referred to as “insulin resistance syndrome,” “deadly quartet,” and “civilization syndrome” [4]. In 2001, the Adult Treatment Panel (NCEP-ATP III) defined metabolic syndrome in adults as the combination of central obesity (waist circumference >102 cm in men, >88 cm in women), hypertriglyceridemia (>150 mg/dl), low HDL (<40 mg/dl in men, <50 mg/dl in women), hypertension (blood pressure> 130-85 mm-Hg), and hyperglycemia (fasting blood sugar >110 mg/dl). In 2005, the International Diabetes Federation (IDF) published a global guideline describing different thresholds for different ethnic groups. According to this guideline, the diagnosis of metabolic syndrome should be based upon central obesity and high triglyceride, low HDL, high blood pressure, and high fasting glucose. The IDF also reported that the presence of at least two factors sufficed for diagnosing anyone as a patient of metabolic syndrome.

as one of the likely pathological findings in metabolic syndrome, central obesity is observed in one in three adults. Hypertension, another crucial factor, is generally acknowledged to be originating from insulin resistance in metabolic syndrome, but the actual features of its development mechanism still remains controversial. Global awareness about hypertension, its treatment, and how to control it is low, and there are significant differences in between people worldwide. A National Health Examination Survey (NHANES) spanning 2011-2014 revealed that 34% of US adults aged 20 years and older are hypertensive and NHANES 2013-2014 data showed that 15.9% of these hypertensive adults are unaware they are hypertensive [5].

Dyslipidemia, which increases as a result of central obesity and insulin resistance in patients with metabolic syndrome, is characterized by low HDL cholesterol and high triglycerides, the most crucial factors that increase the risk of cardiovascular disease. In one study done in 2008, the average total cholesterol levels for American men and women were found to be 197 mg/dl [6].

The presence of overt diabetes or impaired glucose tolerance (fasting blood sugar above 110 mg/dl) indicates the first step of the diagnostic criteria of the metabolic syndrome, and insulin resistance is not sought for further. People diagnosed with metabolic syndrome are 2.34 times more likely to contract diabetes [7]. A 2011 study conducted in America reported that roughly half of all adults have impaired glucose metabolism as a result of type 1 diabetes, type 2 diabetes, and prediabetes. Diabetes has been a prevalent global ailment similar to asthma, autoimmune diseases, and cancer [6].

Insulin resistance, which can be observed in metabolic syndrome, increases the risk of cardiovascular disease by 2.35 times, deaths by cardiovascular disease by 2.40 times, risk of myocardial infarction by 1.99 times, and stroke by 2.27 times, as independent of other risk factors. However, the presence of metabolic syndrome, not obesity, increases the risk of cardiovascular disease [7]. Another significant result is that women with metabolic syndrome have a higher risk of cardiovascular disease than men. Women are more likely to have central obesity than men, have a different cholesterol profile, and higher triglyceride levels that cause more coronary artery disease, while polycystic ovary syndrome, hormone support therapies, and pregnancy diabetes pose additional risk for women [8]. Fatty liver disease, cirrhosis, chronic kidney disease, polycystic ovary syndrome, gout, dementia, and decreased cognitive functions are more common in individuals with metabolic syndrome than the normal population [7].

Treatment of Metabolic Syndrome

Since metabolic syndrome is caused by environmental and genetic factors, and is appearing in people with increasing frequency, the best treatment approaches involve a well-regulated lifestyle, with the main objective being to prevent diabetes and cardiovascular diseases that cause fatal or disabling conditions. Weight loss that results from an appropriate nutrition and exercise program has a corrective effect on almost all disorders observed in metabolic syndrome.

In the treatment of metabolic syndrome, prevention of central obesity seems to be a priority solution. This can be achieved by a lifestyle planning that provides and maintains a 7-10% reduction in total body weight by limiting caloric intake and increasing physical activity. Even methods that increase weekly physical activity by 150-300 minutes and provide only a 5-7% reduction in body weight are considered sufficient to correct the metabolic syndrome. This has especially been reported to have a positive effect on lipid disorders, glucose intolerance, and hypertension, with a 58% reduction in the risk of diabetes with additional lifestyle changes [9].

Since a well-regulated diet is one of the focal points of life style change for people with metabolic syndrome, dietary models that are limited to saturated fats and cholesterol, rich in complex carbohydrates, based upon an abundant consumption of fruits and vegetables, and a restricted use of salt (for those with hypertension) are strongly recommended.

Even though the traditional Mediterranean diet is lauded as one of the vibrant treatment options in the prevention of coronary heart disease and metabolic syndrome, it is not sufficient to correct the metabolic syndrome unless the diet is in tandem with significant weight loss [10]. According to numerous studies, increasing the consumption of nutrients such as fish, vegetables, fruits, dried legumes, and unrefined grains that are rich in olive oil, omega-3 fatty acids, and antioxidants reduce the risk of coronary diseases and death. It goes without saying, that smoking and alcohol use may increase cardiovascular, metabolic and hepatic complications in patients with metabolic syndrome.

Patients with metabolic syndrome should have their blood lipids checked annually, and should be determined to keep low-density lipoprotein (LDL) cholesterol lower than 100 mg/dL, high density lipoprotein (HDL) cholesterol higher than 40 mg/dL, and triglyceride levels lower than 150 mg/dL. Diabetic patients should set their blood pressure target as lower than 130/80 mm-Hg. Changes in lifestyle such as regular exercise and a controlled diet are extremely vital. The use of low-dose aspirin to prevent complications in patients with coronary artery disease is also among treatment recommendations.

The basic sustenance that is provided to us in the form of fruits, animals, grains, and other bounties is such a precious, rich and full-fledged treasure, for which we should be grateful for. However, gluttony and wastefulness pave the way for thanklessness, disease, and even conflicts with the wisdom in the universe.

Almost all living beings are engaged in the pursuit of sustenance and revolve around this goal. We humans have been equipped with the ability to taste and appreciate all kinds of food, and can draw an appreciation for the Divine through these gifts. Just as everything revolves around sustenance, thankfulness has been placed in the center of sustenance. That is, gratitude should be at the center of all sustenance. Through gratitude, we live healthier physical, spiritual, and mental lives.

Notes

1. Meule A, Rezori V, Blechert J. Food addiction and bulimia nervosa. Eur Eat Disord Rev. 2014;22:331–337.
2. Grundy SM. Metabolic syndrome pandemic. Arterioscler Thromb Vasc Biol 2008; 28: 629-36.
3. Moore JX, Chaudhary N, Akinyemiju T. Metabolic Syndrome Prevalence by Race/Ethnicity and Sex in the United States, National Health and Nutrition Examination Survey, 1988–2012. Prev Chronic Dis 2017;14:160287
4. Alberti KG, Zimmet PZ. Definition, diagnosis and classification of diabetes mellitus and its complications. Part 1: diagnosis and classification of diabetes mellitus provisional report of a WHO consultation. Diabet Med 1998;15:539-53.
5. Alexander, Matthew R.; Eric H. Yang. “What is the prevalence of hypertension (high blood pressure) awareness of in the US?” https://emedicine.medscape.com/article/241381-overview#a2
6. Centers for Disease Control and Prevention. National Diabetes Fact Sheet: National Estimates and General Information on Diabetes and Prediabetes in the United States, 2011. Atlanta, GA, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2011.
7. Balcı M.K, Metabolik Sendrom, Türkiye Klinikleri J Med Sci 2008;28:102-106.
8. Mottillo S, Filion KB, Genest J, Joseph L, Pilote L, Poirier P. The metabolic syndrome and cardiovascular risk a systematic review and meta-analysis. J Am Coll Cardiol 2010; 56: 1113-32
9. Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, et al; Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002; 346: 393-403
10. Carbonneau É1, Royer MM2, Richard C3, Couture P4, Desroches S5, Lemieux S6, Lamarche B7. Effects of the Mediterranean Diet before and after Weight Loss on Eating Behavioral Traits in Men with Metabolic Syndrome. Nutrients. 2017 Mar 19;9(3).

It is widely accepted in modern culture that people should eat three meals: breakfast, lunch, and dinner. Nutritionists generally recommend adding two snacks (one in the morning and the other in the afternoon) to help control appetite.

Interestingly, the practice of eating three meals a day is a recent phenomenon. Ancient Romans had only one meal, which they usually had at about four in the afternoon, and they believed it was unhealthy to eat more than once a day. What the Romans ate in the morning and at noon was very light and fast [1]. Later, rules in monasteries affected people’s behavior around food and drink.

During the industrial revolution, breakfast gained importance; workers needed food before work. And dinner didn’t become popular – at least in its current form – until the prevalence of artificial lighting made it possible to eat before dawn and after dusk [2]. The understanding that eating three meals a day is a healthy choice stems from a combination of belief, culture, and early epidemiological studies [3].

There are studies suggesting that having a regular eating habit positively impacts health, regardless of frequency of meals. On the other hand, in a recent and comprehensive study by Kahleova et al., which studied 50,660 adult members of churches in the USA and Canada, it was found that eating one or two meals a day caused lower weight than eating three meals, and also a relatively lower body-mass index (BMI) which got even lower as overnight fasts got longer [4]. The authors state that the positive effects of such a diet are caused by a combination of timing, meal frequency, and overnight fasting, as well as having less frequent meals coupled with precise timing. These results indicate that eating one or two meals is better than eating three or more.

The Prophet’s example

The Prophet Muhammad’s, peace be upon him, recommendations and behaviors lend support to modern medical studies in the area of nutrition, as in many others. He would eat no more than two meals and ensure that one of the meals should consist of light food (such as dates). The Prophet recommended that dinner be eaten, even if it was only a small meal. “Do not leave dinner, even if it is only a handful of dates, because abandoning it makes one weak” (Sunan Ibn Majah).

He defined dinner as the second and last meal of the day, and that it should be eaten after dusk or immediately after the evening prayer.

The Prophet set so many examples about nutrition. He highlighted the dangers of obesity, stating that “What I fear most about my community are developing a belly, oversleeping and idling.” This was centuries ago; nowadays, obesity is an epidemic raging across the world, and its prevalence has almost doubled in more than 70 countries since 1980. In 2015, a total of 107.7 million children and 603.7 million adults were obese [5]. Seventy-five percent of the world’s population is overweight. Obesity, along with dyslipidemia and hypertension, is one of the major factors in cardiovascular diseases. Studies have shown that exercise, as well as meal timing and frequency, are quite effective in weight control [6].

As for table manners, the Prophet said, “The human does not fill any container that is worse than his stomach,” and, “It is sufficient for the son of Adam to eat what will support his back.” Throughout his 63-year-long life, the Prophet never left the table on a full stomach or ate before getting hungry; he recommended that food should not be swallowed without chewing, a practice he maintained. By refusing to sit at tables where there were several types of food, our Prophet was occasionally unable to find anything to eat. There is also no information that our Prophet ever had lunch.

The Prophet’s insistence on fewer meals looks very wise. Not only does eating fewer meals lead to lower incidences of obesity; if it includes a reduction in carbohydrate intake, it can also lead to decreases in total and LDL (bad) cholesterol levels [7]. Considering meal frequency and timing, it is crucial which meals are maintained. In general, breakfast-eaters tend to run a lower risk of weight gain than non-breakfast-eaters – and a significantly lower risk of heart disease [4].

Current studies indicate that food content has as much impact on blood lipids and insulin as meal frequency. Although we cannot fully explain the effects of a single factor on physical health, we are pretty much sure that meal frequencies are closely related to meal timing and which kind of foods are eaten.

The Prophet’s main requirement of food was that it should be lawful and clean, as well as beneficial for the body. His two meals consisted of breakfast and dinner, as is recommended by modern medicine. In a nutshell, the amount of intake and eating etiquette recommended by our Prophet is allocating “one third of the stomach for food, one-third for drink, and one-third for air” (Tirmidhi, Zuhd, 47) and completing meals without getting full. Increasingly, science suggests this may have been good advice!

References

1. Flandrin, J.-L.; Montanari, M. Storia dell’alimentazione; Laterza: Bari, Italy, 2003. 2.Affinita, A.; Catalani, L.; Cecchetto, G.; De Lorenzo, G.; Dilillo, D.; Donegani, G.; Fransos, L.; Lucidi, F.; Mameli, C.; Manna, E.; et al. Breakfast: A multidisciplinary approach. Ital. J. Pediatr. 2013, 39, 44.
2. Potter, C.; Griggs, R.L.; Brunstrom, J.M.; Rogers, P.J. Breaking the fast: Meal patterns and beliefs about healthy eating style are associated with adherence to intermittent fasting diets. Appetite 2018, 133, 32–39.
3. Kahleova, H.; Lloren, J.I.; Mashchak, A.; Hill, M.; Fraser, G.E. Meal frequency and timing are associated with changes in body mass index in adventist health study 2. J. Nutr. 2017, 147, 1722–1728
4. Collaborators, G.B.D.O.; Afshin, A.; Forouzanfar, M.H.; Reitsma, M.B.; Sur, P.; Estep, K.; Lee, A.; Marczak, L.; Mokdad, A.H.; Moradi-Lakeh, M.; et al. Health effects of overweight and obesity in 195 countries over 25 years. N. Engl. J. Med. 2017, 377, 13–27.
5. Paoli, A.; Moro, T.; Marcolin, G.; Neri, M.; Bianco, A.; Palma, A.; Grimaldi, K. High-intensity interval resistance training (hirt) influences resting energy expenditure and respiratory ratio in non-dieting individuals. J. Transl. Med. 2012, 10, 237.
6. McGrath, S.A.; Gibney, M.J. The effects of altered frequency of eating on plasma lipids in free-living healthy males on normal self-selected diets. Eur. J. Clin. Nutr. 1994, 48, 402–407.

The word “obesity” originates from the Latin obesus, which literally means, “having eaten until fat.” Obesity is a disorder involving excessive body fat that damages our well-being and increases the risk of health problems. For example, an obese individual is ten times more likely to have heart disease and five times more likely to have diabetes as opposed to a person of normal weight. Some other symptoms of obesity are high blood lipids (e.g. triglycerides), high blood pressure, and low good cholesterol, which helps remove bad cholesterol from your arteries. Besides leading to a number of diseases, the large waistline formed due to the fat buildup also triggers our immune system, which plays a critical role in the initiation and progression of obesity-associated diseases. Before going into the details of the altered immune response due the increased storage of fat, let’s first explore the perfect order in our immune system, especially in a subset of immune cells called macrophages.

The amazing immune system

Our astounding immune system is in charge of defending our body by clearing out thousands of germs that can make us sick. Our immune cells serve in the context of cleansing the human body from invading germs. The immune system has two branches: the innate and adaptive branches, as defined with respect to the characteristics of their responses. The cross-talk and mutual communication between the two arms constitutes the integral immune response.
The adaptive immune system operates slowly, by developing for specific pathogens. In addition, it has a memory of previous exposures. The innate immune system provides a first line of defense against the invasion of disease-causing microorganisms (pathogens). It has three defense layers: anatomical barriers, humoral barriers, and cellular barriers. The skin is an example of the physical barriers, which prevent pathogens from getting access to our body. The chemicals found in tears, saliva, and mucus impair bacterial growth, and they represent the humoral barriers. Once an invading bacterium somehow evades these barriers, or a tissue injury occurs, various types of immune cells are recruited to the site of infection for the protection of the host. These cells constitute the third barrier of the innate immune system. As an initial defense system, innate immune cells and their components exhibit a fast, non-specific response with minimal memory of past exposures.

Macrophages: the big eaters

Macrophages, a subgroup of such innate immune cells, form a front-line component of our bodies’ defense. The term “macrophage” is derived from a combination of two Greek words – “macro,” meaning big, and “phage,” meaning eater. As the early combatants of our immune system, they are armored with perfectly-tuned ingestion capabilities. Macrophages function like the policemen of our body because they are charged with patrolling nearly all of our body’s tissues, except the heart. They are intensely positioned in tissues where infections are likely to arise, such as the gut and lungs.

There are approximately 200 cell types in our splendid body. Each specialized type of cell is charged to operate like a government or an army. Macrophages are organized to be combative and to secure the body. They possess flawless intelligence, coordination, communication, and movement traits. They are created from differentiating monocytes. Monocytes are produced in the bone marrow and then released into blood circulation. In case of an infection or dangerous threat, they migrate into tissues as early combatants.
To collect intelligence, macrophages are equipped with a large repertoire of sensors or receptors, which are positioned in the cellular membrane and intracellular part of the cellular architecture. These receptors are called pattern recognition receptors (PRRs), whose function is to detect certain structural patterns of pathogens such as bacteria, viruses, parasites, and fungi. Such specific patterns are named pathogen-associated molecular patterns (PAMPs). On the other hand, molecules generated by host cells under extraordinary stress are called danger-associated molecular patterns (DAMPs) which are detected by other specific PRRs. Additionally, macrophages are ornamented with other types of receptors that help recognize and eat extracellular material, including pathogenic microorganisms by a membrane-bound vesicle. This process is phagocytosis, where the pathogen-containing vesicle is ultimately fused with the degradation machinery of the cell (i.e. lysosomes) to eliminate the pathogen.

Once the intelligence is collected by sensors, macrophages become “activated,” meaning that they are mobilized by transmitting and processing the information into the interior of the cell via – from a biologist’s perspective – downstream signaling pathways that initiate the program in the cell nucleus to secrete “alarm” molecules. Such molecules are named cytokines, whose duty is to adjust immune response by aiding cell-to-cell communication and stimulating the movement of macrophages towards the combat zone – in other words, the sites of inflammation.

Metaflammation: a chronic disease caused by obesity

The areas possessing redness, heat, pain, and swelling represent the combat zones of classical inflammation. Such wars are usually short-term and area-specific, with respect to infection and injury; they end with the elimination of the infection and the repair of the damaged tissue, respectively. Unfortunately, chronic inflammation is a different type of prolonged and disorganized immune response. Such a chronic state manifests, a) a low grade increase in immune system markers (inflammation-inducing cytokines); b) a persistent stress response; c) inflammatory effects covering the whole body rather than localized symptoms; and d) a sustained state of the disease. In other words, chronic inflammation corresponds to a lasting state of low-level war all over our body that gradually escalates and leads to various chronic diseases. Interestingly, intense research on the obesity epidemic demonstrated the presence of such low-grade chronic inflammation as the main driver of obesity-associated diseases such as insulin resistance, diabetes, atherosclerosis, pulmonary hypertension, and chronic liver disease. Such an inflammatory state is also termed metabolic inflammation or metaflammation.

The molecular details underlying metaflammation are increasingly better understood. From a scientific standpoint, obesity is characterized by the increased storage of lipid molecules in an expanded fat tissue mass. The macrophages residing in such fat tissues of obese individuals are likely the major source of inflammation-inducing (pro-inflammatory) cytokines, as they seem mobilized mainly due to two reasons. First, the excessive presence of lipid molecules accumulated by overeating are sensed as danger-associated molecular patterns (DAMPs) by various macrophage sensors. Second, macrophages residing in fat tissues have significantly higher level of threat sensors, leading to their easy mobilization. Therefore, the level of such sensors in obese individuals was found to be directly correlated with the severity of obesity-related diseases, such as diabetes and insulin resistance. Moreover, fat tissue macrophage populations are directly associated with the accumulation of fatty tissues in different experimental mouse models. The studies performed in obese and diabetic mice models and patients demonstrated high levels of pro-inflammatory cytokines in blood circulation and fat tissues, contributing to metaflammation.
To simplify metaflammation, excessive fat buildup is sensed as a threat by the big-eating patrollers of our amazing immune system, leading to their abrupt mobilization and continuous secretion of cytokines as “alarm” molecules. The intensity and locality of cytokines simply determines the state of war (i.e. the category of inflammation). In obese individuals, the low concentration of cytokines in blood circulation and fat tissues represents an ongoing low-level war found all over the body, which is metaflammation. Paradoxically, the degree of the war escalates by the enhanced sensitivity of macrophages to cytokines and the gradual increase of cytokines as a result of additional fat accumulation, hence throwing the body out of order and making it vulnerable to numerous diseases.

Apart from excessive food intake, there are other nutritional, environmental, and behavioral factors that give rise to similar chronic inflammation in our bodies. Things such as processed food, traffic-related air pollution, inactivity, inadequate sleep, and stress, can have similar effects as obesity. To protect our splendid bodies from the harmful effects of chronic inflammation resulting from overeating and other factors, we need to carefully think about our external and internal responsibilities. We may need to make intensive, external lifestyle changes, including restricted energy intake, more exercise/physical activity, and a diet high in healthy, unprocessed foods.
As for the internal responsibilities, the most essential part is strengthening our self-control. By doing so, we may improve our willpower, which is needed to resist the temptation to overeat. Otherwise, disrupting the balance of our wonderful body by overeating is an offense and disrespect to its perfect order. Such an imbalanced state pushes our body further toward a biological cliff, to such an extent that the delicately and perfectly organized immune system declares war against the harmful lipid molecules and leads to the emergence of various inflammation-associated diseases. Therefore, to eliminate the risk of imbalances in our superbly designed bodies, we have many internal and external responsibilities to fulfill.

Original article: Czupryn, A. et al., Science 334, 1133 (2011).

Neurons are a highly specialized group of cells that transmit electrical stimuli to elicit responses in the body. This high specialization comes with a price: with few exceptions, neurons cannot divide to replace nonfunctional ones. Over the past decade, cell therapy, that is treatment of a disease by introducing new cells, has emerged as a new hope for neurological disorders such as spinal cord injury, Alzheimer’s disease, and Parkinson’s disease, albeit with numerous challenges. One of the major problems in the field is to make the newly-introduced cells integrate into the neural circuitry of the host organism. This proof-of-concept study showed that it is possible for transplanted neurons to functionally integrate into the host brain and cure obesity in a specific genetic mouse model. This genetic mouse model lacks the ability to sense leptin, a hormone that regulates body weight and metabolism. Thus, these mice are prone to obesity and diabetes. The authors transplanted progenitor neurons isolated from the hypothalamus-a part of the brain that regulates numerous functions including metabolism, hunger and body temperature-of normal embryonic mice to the hypothalami of newborn diseased mice. Twenty weeks after the transplantation, cells were shown to be functionally integrated into the native circuitry. Integrated neurons were able to create electrical stimuli, transmit signals and, unlike the native neurons, respond to the hormone, leptin. Amazingly, transplanted mice were 30% lower in body weight and diabetes-free compared to the obese non-transplanted counterparts. The results were dramatic, despite the fact that only a few of the transplanted neurons were actually converted to the neurons that play a role in energy metabolism and leptin response. The authors explain this phenomenon by stating that the transplanted neurons may work as “antennas” to sense leptin and regulate other neurons in the native circuitry. Although current research is far from human application, it is still an important step towards treatment of detrimental neurological diseases.

2- A new record in solar cell efficiency

Original Article: Yella, A. et al., Science 334, 629 (2011).

Since their discovery in 1991, dye-sensitized solar cells (also known as Grätzel cells) have offered great potential despite their low efficiency values. They consist of dye-soaked titania nanoparticles coupled to an iodide-based electrolyte that allows for absorption of light and its conversion to electricity through the fast transport of electrons. According to a report in Science, researchers from ecole Polytechnique Federale de Lausanne (EPFL) have substantially improved the efficiency values over 12%, making this type of solar cells a feasible contender to the incumbent silicon solar cells. To store the most sunlight, these cells absorb the colors of the light spectrum with the highest energies and reject the rest such as the green light. In addition to the increase in cell efficiency, Grätzel and coworkers have also reduced their cost by replacing expensive ruthenium dyes with a zinc-based dye. Finally, they have improved the voltage output by using a cobalt electrolyte, a redox system that is more compatible than the previous iodide systems. This new system with improved components has also increased the theoretical maximum efficiency to 30%, which will require further optimization in device design and engineering to achieve. The only major drawback is the use of organic solvents potentially limiting the efforts for large-scale fabrication.

3- IQ can still change in teenage years

Original Article: Ramsden S. et al., Nature 479, 113 (2011).

Intelligence quotient (IQ) is a standardized measure of human intellectual capacity that takes into account a wide range of cognitive skills. IQ is generally considered to be stable across the lifespan, with scores at one time point being used to predict educational achievement and employment prospects in later years. However Prof. Cathy Price and colleagues have found that verbal and non-verbal IQ can rise or fall in the teenage years. They tested 33 teenagers-19 boys and 14 girls-in 2004, when they were 12 to 16 years old, and again in 2008, when they were 16 to 20 years old. Each time, the teens took IQ tests that measured their verbal and nonverbal abilities. Then, using magnetic resonance imaging, the researchers scanned the teenagers’ brains while they performed verbal tasks, such as reading or naming objects, and nonverbal tasks, such as solving visual puzzles with their hands. The idea was to match their test scores with a picture of their brain structure and activity at each time. The test results revealed dramatic changes between their first testing and their second: verbal and nonverbal IQ scores of participants rose or fell by as many as 20 points (on a scale with an average score of 100). Some teens improved or declined in either their verbal or nonverbal skills, while others improved in one area and declined in the other. The brain scans mirrored the score differences. For example, in teens whose verbal IQ scores had increased, the scans showed increased gray matter density in a region of the brain activated by speech. Teens whose nonverbal skills had improved showed changes in a brain region associated with motor movements of the hand. The authors note that these were the largest changes observed, and that there might be many more that were not noticed.

4- A coordination path from an infant’s heart to the mother’s heart

Original Article: Feldman, R. et al., Infant Behavior and Development 34, 569 (2011).

A group of researchers sat 40 pairs of mothers and 3-month-old infants face-to-face, equipped with sticky skin electrodes on either side of their hearts. Beat for beat, mother and child’s hearts thumped together almost instantly as they shared loving looks or contented coos. This cardiac coupling worked only for moms with their own babies, and only when the duos synchronized smiles and other cheerful social behaviors. The researchers suspect that when humans mirror each other’s facial expressions, they may switch on specific areas in the brain that tell the heart when to thump. Melding with mom lasts longer than just a few beats, however. Babies who don’t tune in with their mothers are less empathetic as teenagers, according to previous work from the same group. Premature infants or those whose mothers have postpartum depression may be most at risk for losing this social skill because they miss out on early opportunities to interact with their mothers. The authors state that future research is required to examine the impact of interaction synchrony on other physiological processes, such as hormonal release or brain activation.

The world hypertension statistics

Almost a quarter (26 percent) of the world’s adult population suffers from high blood pressure. It is estimated that this number will reach 29 percent by the year 2025. These average statistics based on the adult population of the world includes people of various age groups and from different countries. The risk of hypertension increases with age. While the figure for 20–29 year old males is 13 percent, it increases to 40 percent between the ages of 50–59, and reaches over 60 percent after the age of seventy. Although there are slight variations in women, many of the figures are almost the same (Figure 1).

These figures are quite striking; one out of every two people over the age of sixty suffers from high blood pressure. As for those in their seventies, the figures have already reached almost 70 percent and are expected to increase even further as this group ages. Many diseases in the adult population remain at 1–2 percent; therefore, these figures convey just how common and serious hypertension really is.

The regional distribution of hypertension figures

In contrast with the estimated numbers given above, the figures for hypertension in the different regions present significant variations. Statistically, the number of hypertension cases increases according to the welfare status of the society. In economically developed countries, 37 percent of the adult population has high blood pressure, which is a considerably elevated number in comparison with the world average of 26 percent. Furthermore, 70 percent of the males and 80 percent of the females over the age of seventy living in economically developed countries suffer from high blood pressure. However, in economically underdeveloped countries, the number of hypertension cases is very low.

The hypertension rates in China and India are well below the world averages, with males at 17 percent and females at just 14 percent (Figure 2). In some societies, for example in the Amazon’s catchment areas, the Yanomami Red-Indians, and tribes in the highlands of Papua New Guinea, few cases of hypertension can be found, and blood pressure among these groups does not tend to increase with age.

The reasons for the increase in hypertension

There is a genetic disposition to develop hypertension. The recent studies reveal that high calorie foods, a high level of salt intake, the lack of physical activity, and alcohol intake all play a significant role in the increase of hypertension. By examining these reasons alone, we clearly see how important the prohibition of alcohol is and the Prophet’s words of wisdom advising us to eat less bear on our lives and prosperity in both this world and the hereafter.

Excess of body fat (obesity)

Another recent health phenomenon is the huge increase in people suffering from obesity, mainly due to excessive eating and the lack of exercise. Studies related to disease outbreaks (epidemiological studies) show that obesity is clearly associated with hypertension. These studies also reveal a significant increase in people suffering from both obesity and hypertension. According to these studies, 78 percent of the male and 65 percent of the female cases of hypertension are connected to obesity. Similar studies carried out in various countries confirm that a large number of people with high blood pressure were overweight and that losing weight substantially reduced their blood pressure levels. In fact, the blood pressure in some was reduced by losing weight alone, without the need of any medication.

Many studies also evaluated the connection between obesity and hypertension by measuring the level of the leptin, the hormone that controls the appetite, in the body. High levels of leptin induce stimulation in the sympathetic nervous system and shrink the veins (causing an increase in blood pressure). Another reason for the increase in the activity of the sympathetic nervous system of overweight people is the rise in insulin levels, which in most people can be controlled by diet. Finally, the kidneys of overweight people retain greater levels of salt and water, which causes an increase in blood pressure. These conditions, which on many occasions can prove to be very serious, are in fact contrary to the intended physical state of human creation, as the Prophet Muhammad, peace be upon him, declared in these words of warning: “What I fear most for my followers is a large stomach, excessive sleep, idleness, and the lack of certainty (in faith).”

Excessive salt and alcohol

Evidence from both experiments on animals and clinical studies proves that the excessive intake of salt increases blood pressure. In animal experiments, a high intake of salt in the diet of rats showed a rise in blood pressure, which resulted in strokes. In another experiment, more than 0.50 ounces of salt was added to the diet of several chimpanzees for a period of twenty months. The studies showed an increase of 33 mmHg in the systolic blood pressure and 10 mmHg in the diastolic blood pressure, and when the salt was removed from the diet, the chimpanzees’ blood pressure returned to normal levels. Indeed, salt is an important nutrient for the human body. Sodium, potassium, and calcium salts are essential for all nerve cell activity, for muscle movement, and for the osmotic balance of body fluids. Medical science of today stresses the importance of natural foods, and bread, an important part of our diet, meets the body’s daily requirement of sodium. Thus adding salt to our food and exhausting the kidneys is not necessary.

Various clinical studies on humans have shown that excessive salt in the diet increases blood pressure levels. Salt has been used in the human diet for the past 8000 years, since the beginning of agriculture and animal farming. A human’s normal requirement of sodium is 8–10 mmol/per day. However, in economically developed countries, the daily sodium intake of most people has risen to 140–150 mmol per day (8–9 grams), almost 14–15 times more than the normal physiological requirement. In a study carried out on the subject, 10,000 blood pressure sufferers in 32 countries were closely monitored, and the results showed that as the salt intake was reduced, blood pressure levels dropped. In another study, 24 hour urine samples were analyzed, and here too, a low sodium diet showed a decline in blood pressure.

One of the many health risks of alcohol is its serious affect on blood pressure. Clinical studies have proved that the excessive intake of alcohol causes high blood pressure. The frequent cases of high blood pressure in societies of the former socialist countries and economically developed countries of the present are mainly connected to the excessive intake of alcohol.

As a result, the number of high blood pressure cases in the world has exceeded that of contagious diseases, and this is closely connected to our eating and drinking habits. If humans continue to excessively eat and drink as they are at the present, most people will be suffering from high blood pressure in the very near future.

With this act, the holy Pole meant, “Whenever your son’s spirit prevails over his body, and his heart over his carnal soul, and his intellect over his stomach, and he demands pleasure for the sake of thankfulness, then he can eat delicious things.” (Said Nursi, Nineteenth Gleam, 3rd point.)

I too witnessed a similar incident thirty years ago. With a large group of friends from university I was invited to visit a well-known scholar for whom I had a deep respect. We had the opportunity to attend a dinner with him and among the food served were some delicious cherries. My inner voice said, “If I sit near him, I will not be comfortable enough to eat as many of those cherries as I like.” This was exactly what happened. While I was thinking about how to get a chance to eat more of the cherries, that respected person took one of the cherries, excused himself, and left the table. I still cannot forget how ashamed I was of my thoughts at that time.

As a result of the story of Abdul-Qadir Jilani and my own experience, I started to ponder the activities that function so well in the human body. In medicine, the dynamic balance that entirely governs the body during eating, drinking and digestion is known as homeostasis. The most crucial body fluid in this balance is the blood. All the agents in the blood have a fixed quantity, a fixed measure and are supplied at a constant rate. Blood pressure is stabilized according to the characteristics of each vein. For instance, the average blood pressure of large arteries is about 100 mmHg. If the pressure exceeds this figure, then the result is hypertension. Hypertension can lead to cerebral hemorrhages, paralysis, renal failure, cardiac expansion, cardiac failure and heart attacks, all of which can result in death. As for hypotension, this is when the flow of the blood to the organs, mainly the brain, lessens. Another example of the importance of maintaining balance is that the agents which are responsible for maintaining the concentration of sugar in the blood (glycemia) must be kept at a suitable balance. If the ratio of the blood sugar (glycemia) rises, the person may go into a sugar coma, which is life threatening. However, if the ratio of blood sugar drops, the organs, in particular the brain, are deprived of energy. A hypoglycemia coma (when blood sugar is too low) is even more dangerous for the brain than hyperglycemia (when blood sugar is too high). The concentration of sodium, potassium, chlorine, calcium and fatty acids present in the blood, like sugar, are kept in a dynamic balance. If this concentration is upset, the result may be disease or even death. The Owner of Absolute Will and Infinite Mercy keeps all these in balance thanks to the marvelous mechanisms that He has placed in our bodies. However, we are free as far as actions like eating and drinking are concerned, for we are granted the willpower to choose our actions.

Balance in nourishment

One of the most often discussed medical subjects in recent years is obesity. This is an important health problem that poses a threat to life, and it is related to diabetes, hardening of the arteries (arteriosclerosis), fatty liver, cirrhosis, cardiac failure and heart failure. Apart from using one’s own will power and eating less, doctors have presented other harmless ways that are appropriate to human nature to treat obesity. Being overweight constrains the ability of a person to move (exercise) and this inactivity, in turn, leads to more and more weight gain. God has enabled us to seek nourishment wherever we like, within certain parameters. Naturally, our stomach has a certain capacity and when this capacity is met, we feel full and do not need to eat any more. Yet, even though we feel full and should not eat, as this is what is necessary for the health of our body, we are overcome by our lower self and tend to overeat extravagantly. The problem of obesity seems to be greater in developed countries.

Our Creator has not put any restrictions on the absorption of food into the blood. All the food we eat is taken into the intestines so that the nutrients can pass into the bloodstream. If the dynamic balance (homeostasis) were to be maintained here as well then the body would take as much as it needed and the surplus of food would be evacuated from the body without going into the blood; as a result, obesity would not be a concern, however much a person might eat. But by allowing all the food we eat to pass into the bloodstream, the Absolute Ruler has set a test for us, challenging our wills and warning us about self-control.

Most of the activity during digestion and absorption takes place in the small intestine. Our small intestine is a duct which consists of three parts, namely the duodenum, jejunum and ileum, each having different functions and structures. The length of the intestine is 3–4 meters, and it measures 2–4 centimeters in diameter, varying according to the position in the body. The area of the inner surface of this cylindrical structure is 1,600 cm2 (0.16m2) at its maximum. The inner perimeter of the intestine is not like a flat tube, but rather it has folds, each measuring about 8 millimeters, that stretch over the inner parts of the canal. These folds allow the absorption surface to be increased about threefold. If the inner surface of this structure were flat, the absorption capacity of the small intestine would not be more than 1/600 of its present capacity. The surface of these folds is also not flat, but covered with protrusions called villi that are shaped like a finger; these stretch into the vacuum of the canal by about 1 millimeter. There are between 20 and 40 villi to every square centimeter on the surface of the intestine. These villi allow for there to be a tenfold increase in surface absorption. The surface of the villi has cylindrical cells that are arranged in a single row and these help in absorption. The surface of these cells has extensions that are quite thin and dense, known as microvilli, or epithelial cells. Thanks to these cells with a brush border surface, the absorption surface can increase by about twenty times. Thus, although the surface area of a flat canal of the same size should be approximately 3,300 cm2, thanks to surface folds, villi and bushy edges, the total absorption surface of the small intestine increases to 2 million cm2 (200 m2). Moreover, some research has suggested that the total increase could be even greater (about 1,000 times as much). Normally, 100 grams of fat, 50–100 grams of amino acid, 50–100 grams of iodine, and 7–8 liters of water (consisting mostly of fluids produced within the body) are absorbed by the intestines daily. Furthermore, if one eats or drinks too much, the maximum capacity of the system allows the absorption of several kilograms of carbohydrates, a half to one kilogram of fat, a half to one kilogram of protein and twenty liters of water per day. Our intestines have been created with the capacity to transfer all this food into the bloodstream. If we do not control our eating, this capacity is abused and we can face conditions like obesity.

In this life, one of whose tests is in our body, and in which we are required to strive hard using our willpower, there is no limit to the absorption of foods that have high calories (lipid, carbohydrate, and protein), and this can lead to being overweight, as mentioned above. However, in the absorption of minerals, which are not normally considered as making up the basic components of nourishment, but which are of the utmost importance for the human body (in all the operations of the nerves, muscles, bones and in the balance of all the electrolytes), the rules of dynamic balance occur in our intestines, regardless of our will, by the help and mercy of God. For instance, hemoglobin, which is found in the red blood cells (giving the blood its red color) and is charged with the task of transporting oxygen, contains iron. When there is surplus iron in the body, hemosiderosis occurs, which leads to the destruction of organs such as the liver and the pancreas, or cardiac failure. If there is an iron deficiency, then a person suffers from anemia. It is for this reason that a quite sensitive iron-absorption balance exists in our intestines. Here, it is evident without question that there is Divine Aid and Mercy. The same mechanism works for substances like calcium.

Prophet Muhammad’s, peace be upon him, advice to stop eating before feeling full is a significant measure against obesity, for it eliminates “false” appetite. This has a psychological truth, for the brain responds to the feel of fullness a short time after eating. In fact, we all know by experience that we actually feel full a short while (fifteen–twenty minutes) after we stop eating even if it is a small meal.

To conclude, the Almighty One warns us against extravagance and orders us to use our willpower. At this point, we can see how important a role the blessing of religious belief and the training of the soul and the will play in eating habits. Likewise, the principles of Islam, which is in perfect keeping with human nature, are crucial for the well-being of the community as a whole; charitable alms and fasting, which urge us to help and think about those with less, are obligatory and all kinds of charity and good deeds are encouraged. In Islam extravagance is prevented, not only in eating and drinking.

Omer Arifagaoglu is a professor of medicine in Turkey.

Obesity is harmful to infants as well as adults. Obesity during infancy may, in later life, cause such diseases as arteriosclerosis and the other ailments which often accompany it. Arteriosclerosis in adults is a factor in high blood pressure or hypertension, and in certain diseases of the heart eyes and kidneys. Obesity can also lead to diabetes.

There is a good deal in classical Islamic sources on the subjects of over-eating and obesity. The Qur’anic verses. Eat and drink but not to excess (7.32), and Do not cast yourselves into destruction by your own hands (2.195), may be mentioned (besides their other meanings) as Divine warnings against transgressing the limits in eating and drinking and doing harm to ourselves because of carelessness. All ibn al-Husayn ibn al-Wafid said. God put all medicine into half of one verse [of the Qur’an] when He said: Eat and drink but not to excess.’ The Prophet, upon him be peace and blessings, also drew attention to obesity and over-eating. For example, as recorded by al-Haythami, on seeing a fat man, he said: If you did not have a paunch, it would be better for you. He also said: Overeating does not go with good health. The criterion established by Islam, and reiterated by the Prophet, is: The middle way [avoiding extremes] is the best in every affair.

Among other sayings of the Prophet which warn against the dangers of overeating and obesity are:

Avoid filling the stomach with food and drink. Overeating exhausts the body and causes illnesses. Follow a middle way in eating and drinking as this improves the body. God does not love fat bodies.

The son of Adam [i.e. man] fills no container worse than his stomach. Let him have just a few mouthfuls to strengthen the limbs.

One third of the stomach is for food, one third for drink, and one third for air.¹

The following saying uttered in relation to the spiritual harm caused by over-eating, can also be read in relation to heart diseases arising from overeating:

Do not kill your hearts by eating and drinking too much. For the heart is like a sown field: over-irrigation causes the seed to rot.²

‘Ali, the fourth Caliph, said:

Having suet is a disease. He also said: Fullness causes heart spasms.³

‘Umar, the second Caliph, said: Avoid getting a pot-belly, for it spoils the body, causes diseases, and makes doing the prayer tiring. And avoid all excess, for God hates a learned man who is fat.⁴

Harith ibn Khalada, the physician of the Arabs, was once asked: What is the best medicine? He replied: ‘Necessity- that is, hunger.’ When asked what the disease was, he said:

‘The entry of food upon food.’

lbn Sina, the renowned Muslim physician and philosopher, said: ‘Never have a meal until the one before it has been digested.’ He also advised against excessive salt and fatty meat. His list of food for dieting mostly included vegetables. The prescription is much the same today.

The Prophet, upon him be peace and blessings, also drew attention to obesity and over-eating. For example, as recorded by al-Haythami, on seeing a fat man, he said: If you did not have a paunch, it would be better for you. He also said: Overeating does not go with good health. The criterion established by Islam, and reiterated by the Prophet, is: The middle way [avoiding extremes] is the best in every affair.

The Prophet declared:

Avoid filling the stomach with food and drink. Overeating exhausts the body and causes illnesses. Follow a middle way in eating and drinking as this improves the body. God does not love fat bodies.
The son of Adam [i.e. man] fills no container worse than his stomach. Let him have just a few mouthfuls to strengthen the limbs.
One third of the stomach is for food, one third for drink, and one third for air.¹
The following saying uttered in relation to the spiritual harm caused by over-eating, can also be read in relation to heart diseases arising from overeating:
Do not kill your hearts by eating and drinking too much. For the heart is like a sown field: over-irrigation causes the seed to rot.

Contrary to some popular superstitions, fat babies are not healthy babies. On the contrary, over-eating is also harmful for children. Children fed on starchy foods without the necessary amount of vitamin D are susceptible to rickets (rachitism). Ibn Sina advised the same nine centuries ago: ‘Avoid giving babies too much food. Over-nutrition of babies causes their urine to be light-coloured’. The fact that a baby goes on suckling does not always mean that the baby is hungry; sometimes suckling is just a reflex action. Dark-coloured urine in babies indicates undernutrition; while a light colour is symptomatic of overnutrition.

Ibn Sina was of the opinion that over-feeding provokes eclampsia (convulsions) in babies. Anther Muslim physician, Abu Bakr al-Razi, also pointed to this link. He said that some infantile convulsions can abate after proper regular nutrition. lbn Sina and al-Razi may have been referring to the kind of eclampsia caused by rickets emerging as a result of obesity: in the syndromes named after Frohlich and Martin-Albright obesity is accompanied by eclampsia.

Ibn Khaldun, a Muslim sociologist and historian famous for his Muqaddima, also mentioned that over-eating causes many diseases. He said: ‘Know that hunger is better for health than eating too much. Even if we cannot remain hungry, eating less is good. Eating less is better for the development of body and mind.’⁵

Other Muslim physicians such as Haji Pasha and Hafiz Hasan Effendi also wrote that giving babies too much milk was harmful for their health. It is now a well-established fact that feeding babies too much milk causes obesity.

Advice on eating and drinking

There are many sayings of the Prophet Muhammad, upon him be peace and blessing, on medicine. They encompass a great variety of subjects including eating and drinking and the mention of certain kinds of food particularly useful for health. In later centuries Muslim scholars collected these sayings, usually under the title of Tibb al-Nabawi. The collections of lbn Qayyim al-Jawziyya, Jalal al-Din al-Suyuti and Abu Nu’aym are among the most famous.

Jalal al-Din al-Suyuti (d.1505), one of the greatest scholars of the Muslim Middle Ages, recommended eating cold foods in summer and hot ones in winter. Hot food should be preferred with cold, sweet with sour, fat with salt and acid with fat. Variety of foods excites the constitution; it is best to eat with relish and enjoyment. Having the same food several times one after the other and eating hurriedly causes loss of appetite and laziness. Eating a second meal without fully digesting the first is harmful. Al-Suyuti also wrote that one should avoid food and drink that has been left uncovered. The Prophet, upon him be peace and blessing, commanded this: Cover your containers and stop up the mouths of your water bottles.

The Prophet disapproved eating food while it is too hot. He never used to blow on his food or drink, or breathe into a container. He also forbade eating lying down.

Taking a walk after eating a meal or doing the prayer is beneficial, specially for the digestive process. The Prophet said: Digest your food with the Name of God and with doing a prayer. And do not go to sleep immediately after eating as this will make you constipated.

The hands should be washed alter as well as before eating. One whose stomach is over-stuffed with food cannot think clearly or wisely. The less a man eats, the less he drinks; and the less he drinks, the less he sleeps; and the less he sleeps, the better he will be in old age. The body of a man over-filled food will be badly nourished, his self will be in a bad state, and his heart will grow hard. Therefore one should avoid too much food as it poisons the heart and slows down the limbs of the body in fulfilling one’s responsibilities toward God. One should also avoid drinking very cold water, for it is harmful to the respiratory system, specially after a hot meal, or after sweet food, or after a hot bath.

The Prophet, upon him be peace and blessing, forbade drinking water at a single gulp. Anas ibn Malik transmitted the tradition that the Prophet used to drink with three pauses and, at each pause, remove his mouth from the container.

Healthy exercise

Moderate exercise is a most effective means of preserving good health. It warms the organs, helps dissolution of waste products, and makes the body light and active. The best time for exercise which does not over-tire the body or make it red. When sweating begins, exercise should be stopped. The type of exercise which increases sweating is not ‘moderate’ but ‘heavy’.

The body’s organs are strengthened and made more vigorous by regular exercise. The same applies to the inner faculties. One who wishes, for example, to improve his memory will improve it by memorizing. There is a specific exercise proper to every organ.

The Prophet, upon him be peace and blessing, advised a form of exercise which is good for our bodies and our hearts when he said: Travel, for you will grow healthy. He also said: Fasting brings health.

Sleep

According to al-Suyuti, the best time to go to sleep is after food has been digested. Over-sleeping is bad for the health; and sleeping face down is forbidden. Sleeping during the hour following sunrise and before sunset is bad for one: it may lead to ailments and indolence. However, a short sleep in the middle of the day is useful for the health and helps one to rise for prayer during the night.

The Prophet, upon him be peace and blessing, used to sleep on his side, facing the qibla (the Ka’ba in Makka). And it is better o go to sleep in a state of wudu.

References

1. The narrations can be found in Tanbih al-Ghafilin by Abu’I Leys al-Samarkandi, (Turkish translation), p. 799, and, lhya Ulum al-Din by Imam Ghazali (Turkish trans.) Vol. 3, p. 186.
2. al-Ghazali, ibid., 3.186.
3. Celal Yildirim, Asrin Kuran Tefsiri, Izmir, :1987, 1.478.
4. Imam Dhahabi, Sifa Demetleri, Istanbul, 21.
5. I. Haldun, Muqaddima (Turkish trans.), Ank. 1977, 1.232.

No religion commends self-indulgence;all religions, and all traditional ways of life inspired by religious principles, commend self-discipline, that is containing and limiting, rather than expanding, one’s needs. Islam, with its conspicuous patterns of regular prayers, fasting and taxation of one’s wealth and property is particularly emphatic about the importance of self-discipline. Within the norms of Islam, self-discipline means a controlled, moderate, balanced way of living – not orgies of self-denial, followed (inevitably enough) by orgies of self-indulgence. Modern Western ways of life are not traditionally based, not inspired by religion, but motivated instead by what the economic market requires, which is for individuals to spend more and more, regardless of need. One area of such spending is food and drink: certainly among the better-off classes in Western societies, food is purchased, partly eaten and partly wasted, on an unimaginable scale. Muslims who are responsive to the Qur’an’s command to avoid squandering and waste, and to avoid activities or habits which cause harm to oneself (as over-indulgence always does), can never feel at ease living according to the modem Western values and norms.

But the reality is that non-Muslims cannot do so either, at any rate not for long, certainly not for ever. Just as over- exploitation and abuse of the environment demands, sooner or later, a return to saner and ethically more sound relationships with the earth’s finite resources, so too overindulgence at the level of individual lives demands, sooner or later, a return to a healthier life-style, a simpler, more sustainable diet. For the present, this reassertion in Western societies of the saner traditional norms (which, as we have noted, are common to all religious traditions) appears in many individual lives as an unpredictable swing between extreme over-indulgence (visible as obesity) and extreme self-denial (seen in crash courses to lose weight). It is true that vast, even obscene, amounts of wealth are engaged in the slimming industry which (as it were) feeds on the inability of many people to achieve a change in life-style and eating habits which they can sustain. Nevertheless, there is a growing understanding that, in the end, fat-free fats are a real waste of energy: the only point in slimming foods and dieting generally is to train oneself to live in a different, healthier way, and do it for good.

What is obesity?

Generally, obesity is regarded as being synonymous with being overweight. This is not strictly accurate. What actually matters is the excess of fat present in the body. One man may be overweight because he sits all day and eats but does no exercise; another, say an athlete, may be overweight because intensive training has increased his muscle bulk. The first man might be called obese, the second could not. However, as it is difficult to measure the amount of fat present in the body but easy to measure weight by simply using scales, the terms overweight and obesity are for everyday purposes interchangeable.

Does obesity matter?

Statistical studies (done by life assurance companies who have to be good at assessing health risk) provide undeniable evidence that obesity increases morbidity (illness) and the likelihood of early death. Fat people are more likely to suffer, among other things, from increased blood pressure (which may be the cause of stroke, kidney disease or coronary thrombosis), diabetes, arthritis, gallstones, varicose veins, complications of pregnancy or labour, and post-operative problems. Other illnesses not necessarily directly caused by obesity may be aggravated by a person being overweight. For example, a man suffering from angina (pain caused by impaired circulation of blood to the heart muscles) is more likely to die suddenly if he is overweight than if he is of normal weight. Obesity matters therefore because it can lead directly to illness (often serious) and reduces lifespan.

Causes of obesity

The one obvious and direct cause of obesity is that food intake is in excess of the body’s energy requirements or, in plain English, overeating. Why do some people eat more than they need?

By far the commonest reason is that their energy use slows down while their food intake remains the same. This happens in many people as they grow older because little by little they slow down physically, whereas their eating habits remain unaltered. This leads to the well-known condition of middle-age spread. Just one potato or one slice of bread more than the body needs each day can add to its weight each week until, perhaps, by the end of the year the excess amounts to a whole stone.

The genetic make-up of some individuals can make it difficult for them to avoid putting on excess weight because their bodies function at a low metabolic rate. Many fat children, though by no means all, probably fall into this category. It is well recognized that fat parents often produce fat children, and it is unlikely that this phenomenon can he explained entirely on environmental grounds as the children adopted by fat parents are no more likely to become fat than other children.

There are people who overeat because they have a psychological or psychiatric disorder of a lasting kind. Others may overeat when they are temporarily depressed or under emotional stress: they look for consolation for their trouble in eating. For example, some cigarette smokers when trying to give up their bad habit try to compensate by eating. It has also been suggested that, after giving up smoking, the bowel tends to absorb food more efficiently which may aggravate the problem of increased weight.

According to a theory that has been popular for some years now children who are allowed to become fat during the first two years of their lives form a large number of fat cells. They then spend the rest of their lives filling up these cells with fat that is, they have an increased predisposition towards depositing fat within their bodies. However, though popular, this theory has not yet been proved.

Cultural norms and expectations influence people in all sorts of ways, among them, in the way they look. In most Western societies of the present, the cultural preference is for slimness. But this is not true of all societies, not even all Western ones – for example, in southern Italy and elsewhere in Europe, a mother is expected to be ‘well-rounded’.

Treatment of obesity

Treatment of obesity requires a reduction of calorie intake to below the level of the body’s daily energy requirements. Weight will he lost only if there is a negative calorie balance. Eating less food than the body requires means that the body uses up its own fat to meet its energy requirements. In extreme cases, where losing weight is of paramount importance and where, for one reason or another (usually psychological), dieting has failed, surgical procedures may be necessary. These can include wiring up the jaws to prevent entry of solid food while allowing liquid matter to enter the mouth, or even more rarely, short-circuiting large sections of the bowel, a high risk procedure that carries with it a very significant mortality rate.

Nutrition and diet

Nutrition is concerned with the correct provision of essential factors for body growth, maintenance and repair, together with the necessary number of calories to meet the body’s energy requirements. A correct slimming diet is one that reduces the daily intake of calories without depriving the body of its nutritional needs. Some understanding of nutrition and correct dieting is important not only for those who are already obese, but for many young, normal individuals who, without this knowledge would be likely in the course of time to become obese. A well-balanced diet must have adequate amounts of proteins, carbohydrates, fats, vitamins, minerals, mineral salts and water. Proteins, fats and, particularly, carbohydrates, are important sources of calories and hence of energy. Proteins also supply the amino acids essential to body growth and repair. Fat in addition to being a subsidiary source of energy is the principal source of some vitamins.Vitamins are important in the utilization of energy and in the body metabolism but are not themselves a source of energy and do not contribute to body weight. Lack of vitamins causes disease but so too can an excessive intake of some vitamins. 

A number of mineral salts are essential for the human body. Iron, for example, is essential for the formation of hemoglobin. Calcium is necessary for ossification of bone (the change of cartilage into bones). Phosphorus is required for many purposes including the manufacture of ATP. Iodine is necessary for the correct functioning of the thyroid gland. Other important minerals include potassium and sodium.

Water is one of the most important elements in our diet. It makes up about 70% of body weight and shortfall in its intake results in dehydration. Caloric foods are essential for body energy requirements. To appreciate their importance it is necessary to understand both how calories are expended by the body and how these calories are provided by the food eaten. The total calories expended by the body each day is the sum of the calories required for basal metabolism and those required for physical activities. Basal metabolism is the chemical change occurring within the body in the state of complete physical rest when the only bodily functions that are occurring are respiration, growth and repair of body tissues. Physical activity includes obvious exercise such as walking or running and other activities such as digestion and absorption of food. The requirements of basal metabolism depend on the size of the person, but on average about 1,700 calories per day. For comparison it is interesting to note that walking utilizes about 200 calories per hour, household work about 100 calories per hour, and mental work no calories.

Calories are provided by certain constituents of the diet. The most prolific source on a calorie-per- weight basis are fats, which yield 9 calories per gram, followed by carbohydrates and proteins which each yield 4 calories per gram. It would appear that, in order to lose weight with maximum efficiency, the part of the diet which should be reduced is the fat content. However, the average diet contains nearly twice as much carbohydrate as it does protein and fat put together. Therefore, in practical terms, most slimming diets concentrate on the reduction of the carbohydrate content of the food eaten.

Dieting

By ‘dieting’ people usually mean a ‘reducing diet’, that is, a programme of eating less in order to achieve weight reduction. But there are other types of diets used for different purposes such as lowering the level of cholesterol or increasing the bulk content of food in the bowel.

Reducing diets are designed to provide less calories in the food intake than are used by the body in the expenditure of energy. There are infinite variations, both in the content of such diets and in their efficacy.At its simplest, good diets are diets that work. The important criteria of such diets are:

1. Palatability: it is pointless following a diet which forbids all foods that one likes and allows only foods that one dislikes.
2. Practicability: that is a diet that can be followed with a minimum of fuss and preparation and can be used when one is out at work or at a restaurant.
3. Moderation: a diet should be one that ensures a weight loss of not more than 2 lb a week. Diets which produce weight loss in excess of 2 lb are usually crash diets and come into the second category namely, bad diets.

Bad diets fail to satisfy the criteria described above. They fail because they are monotonous or cause tremendous hunger and are soon abandoned, with a consequent return to previous eating habits and the regaining of weight lost. Even if maintained with perseverance and weight is successfully lost, when the diet is eventually stopped, when the desired weight has been achieved, former eating habits are almost always resumed and weight rapidly regained. Weight rapidly lost is weight rapidly regained in almost every instance. It hardly needs saying that the most important aspect of dieting is the re-training of one’s eating habits so that after a time dieting is no longer a conscious activity but a totally natural and permanent way of eating for health. In practical terms the most effective way of achieving this is by gentle reduction of the amount of food eaten. For example, one potato less, one slice of bread less, substitution of artificial sweeteners instead of sugar, are all ways of reducing calorie intake in a gentle and painless manner. There are numerous other tactics (usually classed as behaviour therapy) such as eating from a smaller plate, which can all help different individuals to adapt gradually and permanently to a different regime of eating.

Slimming tablets are controversial. Opinion as to their usefulness is divided. They appear to be very popular with patients but not so popular with doctors. It is possible that tablets have a use particularly when hunger is a problem during sensible dieting or when the reduction of weight has reached a plateau which appears to be permanent or long-lasting. A short-term plateau is a common occurrence while on a reducing diet and perseverance is required as weight loss is usually resumed after a short period. The problem with slimming tablets is that they can cause unpleasant side effects such as insomnia or, conversely, drowsiness, and they may cause dependency. 

Exercise

The importance of exercise in the context of weight reduction is frequently overstated. For example, a walk of one mile will probably use up less than 60 calories. If this activity is undertaken every day it will probably achieve a weight loss of less than 1 lb a month. However studies have shown that sedentary individuals appear to lose weight with more difficulty than active individuals on identical diets.

Bran

Recently doctors have become aware of the importance of something that has been missing in the refined diets of Western societies for a long time: this is vegetable fibre. Observation of peoples in the African continent have shown that the local inhabitants rarely suffer from constipation, bile and other bowel disorders so common in Western countries. This has been convincingly explained as being due to the presence in their diet of vegetable fibre. The theory has been advanced that if vegetable fibre is added to our Western diet the incidence of such bowel disorders will be reduced and this appears to be borne out. The addition of vegetable fibre, generally in the form of bran, may well prove to be a useful constituent of our everyday diet. A further advantage of bran, particularly while on a reducing diet is that it has a tendency to fill up one’s stomach and thus alleviate hunger.

Diet and corona heart dease

Cholesterol is a fatty substance present in everyone’s blood. It causes problems as it is deposited in the lining of arteries making them narrower. Cholesterol also forms an important constituent of arteromatous plaques (lumpy deposits on the inner lining surface of arteries) which may cause narrowing or blockage of the coronary arteries (those supplying the heart), leading to pain on exertion (angina pectoris). Blockage of the coronary arteries causes coronary thrombosis which results in destruction of the heart muscles. The relationship between high blood cholesterol levels and coronary heart disease is undisputed. Numerous studies have shown that the risk of dying from coronary heart disease is more than doubled if one has an abnormally high level of cholesterol in the blood. The relationship between blood cholesterol levels and coronary heart disease is probably a direct causal one. The classic observation is that Japanese men who came to live in San Francisco acquire high blood cholesterol levels and suffer an increased incidence of coronary heart disease in similar proportions to those of the indigenous population and in marked contrast to the low cholesterol levels and low incidence of heart disease of the indigenous population of Japan. However, the possibility remains that some other factor or factors are responsible for both the high cholesterol level and coronary heart disease has been postulated.

Cholesterol is derived partly from the diet and partly from the breakdown of other food substances within the body. The main sources of cholesterol are animal fats and dairy products. These include fatty meats, liver, milk, cheese, cream and butter. All these foods contain a good deal of saturated fatty acid which in the body breaks down to form cholesterol. In addition, eggs contain pure cholesterol. When the amount of cholesterol and saturated fatty acids in the diet is reduced the level of blood cholesterol is also reduced.

What does seem likely is that even a moderately raised level of cholesterol over a long period of time may predispose towards coronary heart disease. Doctors and nutritionists are therefore becoming increasingly aware of the importance of correct diet starting in childhood. It is likely (and certainly it is to be hoped) that, with increased general awareness of the importance of cholesterol levels, there will be some alteration of the present eating habits in schools – informed teachers could provide an important impetus. This is particularly desirable as the eating habits of adults and their likes and dislikes are acquired largely during childhood. There should be a trend towards a reduction of the animal fat and dairy product content of the diet (though by no means their total exclusion because they still form an important source of certain essential nutrients) together with an increase in food containing more polyunsaturated fats (which do not lead to the rise in cholesterol levels) such as lean meat and the substitution of soft margarine high in polyunsaturated fats in place of butter, and the use of corn oil, sunflower oil and safflower oil in cooking instead of cooking fat.

As Muslims, of course, we must be abstemious and refrain from overindulgence. Good health is a valuable gift from God Almighty and we shall he held accountable for how we treated our bodies. In the inimitable words of the Wise Qur’an: Let not your own hands contribute to your own destruction’.