The foot is a limb that is not given much importance when compared to other vital organs such as the brain or heart. However, the foot is a very complex mechanical structure that is made of 26 bones, 33 joints, and more than 100 muscles and ligaments. About a quarter of the bones in the human body and about a fifth of the joints are found in our two feet. That is why Leonardo da Vinci described the human foot as an engineering and artistic masterpiece.

A healthy person takes about 5,000 steps a day. Given a life of eighty years, a person takes about 150 million steps throughout their life. Assuming that each step is 75 cm, a person walks about 110,000 kilometers throughout his life. This corresponds to walking around the equator about 3 times. Apart from that, a typical person stands for around 2-4 hours a day. During all these activities, the human foot carries the entire body’s weight. In standing position, body weight is supported by two feet while activities such as walking and running are done by only one foot for a certain period of time. While standing, the feet carry 100% of their body weight, while walking, this rate rises up to 150%. While walking, the foot that needs to be lifted from the ground approaches the ground again with an acceleration in the same direction as gravity. Therefore, the impact force at the moment the foot touches the ground corresponds to 150% of a person’s body weight. In cases of severe effects such as running and jumping, this force easily increases up to 5 times the body weight and up to 10 times in some people. For a person weighing 70 kilograms, this force can be 105 kg (or about 1050 Newton) in walking, and easily 350 kg (or about 3500 Newton) in running or jumping. Assuming that a person walking for an hour takes 5,000 steps, the foot pulls a total of about 500 tons of load (5,000 steps x 105 kg). In running, this figure will increase approximately three times.

The foot has been created with a wonderful mechanical and construction design that is able to consistently sustain such high loads. The bones and muscles of the foot add two different belt designs to it. One of them, the structure called the longitudinal belt starts from the heel bone (calcaneus) and ends with its metatarsal bones (Figure 1). Some researchers claim that the long arch is divided into two parts as the inner (medial arch) and the outer arch (lateral arch). However, both structures resemble bridges built in arches. The second arch on the foot is called the transverse arch. This belt is perpendicular to the long belt from the right side of the foot to the left side and is shorter in length (Figure 2).

Therefore, the foot is a marvelous structure consisting of roughly two arches. This structure of the foot can be compared to arch bridges or a dam. The arch structure is known as the strongest structure against steep loads in construction areas due to the robustness of the designs against compression forces in cases of vertical loading. Therefore, hydroelectric dams are constructed in the form of arches or arcs in order to make the most resistant model against hydrostatic pressure.

The arch structure of the foot is very flexible and can also move up and down like a car suspension and acts as a shock absorption. If there was no such structure on the foot, the impact forces during walking and running activities would be higher and cause chronic foot pain. The flatfoot complication is a result of a damage in the arch structure in the foot which comes from birth or develops afterwards. Flatfoot patients are often unable to perform long-term activities and experience foot pain as well as complications in other organs of the body.

Our feet’s arch structure is not the only factor involved in shock absorption that is designed against mechanical forces. The layer of fat on the bottom of the foot also contributes to this process. In a healthy person, this fat layer, which has a height of 2.5 cm under the heel, drops to 5-7 mm in the front part of the foot. It also helps to distribute the vertical and horizontal forces caused by standing or walking evenly on the sole of the foot. At the same time, it serves as a source of heat insulation and helps protect our feet from hot or cold surfaces. In some diseases such as diabetes, in which this fat layer melts or decreases, wounds called foot ulcers can develop because the shock absorption and load distribution get damaged. Mechanical pressure is calculated by dividing the amount of mechanical force by the surface area on which it is applied, meaning that smaller surfaces areas are subjected to more pressure. This is why very tiny needles, despite weighing almost nothing, can pierce our skin and cause pain. Similarly, damage to the fat layer under the foot causes the forces applied under the foot to act on a limited surface area. For example, the reduction of fat in the area just below the heads of the metatarsal bones reduces the “cushioning” effect in this area and causes a pressure in high values. This extra pressure can cause tissue damage along with the aforementioned foot ulcers.

Such a situation that will cause pain in a normal person cannot be felt by many diabetics. If diabetes is not well controlled, neuropathy or a “lack of feeling” may occur as a complication. Dead nerve cells become unable to feel pain which can result in people not knowing about harm that is being done to their body. Diabetic patients who develop neuropathy would not feel fatty layer damage and accompanying high pressure values whereas a typical person normally would. Untreated foot ulcers can become infected and can turn into gangrene. Since the gangrenous foot has to be cut, diabetes unfortunately causes a large number of amputations. Such amputations are sadly quite frequent throughout the world due to diabetic neuropathy. Dr. Paul Brand, who studied diabetic foot ulcers, defined pain as a gift from God that no one wanted. Sometimes, what we do not like might be better for us (Qur’an 2:216); likewise, pain can cause a lot of trouble to people but it can also alert us of dangers and harm to our bodies.

Thus, foot care is very important in diabetics. The following three actions are recommended to patients; daily inspection of the foot; daily washing; and control of the inside of the shoes. The pest, pebble, or similar hard object in the shoe that can be very harmful for diabetics with loss of sensation would be removed this way. On the other hand, when such a hard object remains in the shoes, patients may step on them repeatedly without feeling it which will likely lead to an ulcer case.

With its pain that works like a health alarm, extraordinary mechanical loads it carries, heat insulation and shock absorbing features, the human foot is a wonder of art that calls for contemplation.

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.

“Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.” Cree Indian Proverb

The table I have under my laptop while writing this article, the materials used for my laptop, the cover case for my phone, the pen I have by my phone, the package for the mail I have received, the dividers I have in my notebook, the hair dryer I have for drying my samples before performing FT-IR on my samples, the FT-IR machine itself … They are all made up of plastics. I could go on and on, giving examples of what I observe in my immediate environment made of plastics. It would not be exaggerated to say that after the Stone Age, Bronze Age, and Iron Age, we are now living in the “Plastic Age” given the fact that the production of plastics has increased from 1.5 million tons per year in the 1950’s to 260 million tons per year in 2007.1 The majority of plastics we use in our daily life are petroleum-based plastics. What that means is, the starting materials of these plastics are chemicals derived from crude oil. There are some major concerns related with these petroleum based plastics – the Earth may run out of oil one day, or the questionable durability of how these plastics biologically degrade. Further environmental concerns exist, such as the toxic additives these plastics contain, including plasticizers like adipates and phthalate. Burning these plastics can release billions of tons of toxic pollutants every year; moreover, most plastic production reactions are done in toxic solvents, so the disposal of these solvents becomes a problem.2 Reflecting on it, it’s an incredible mercy that we have been able to get away with all the waste we have produced up to this point. But the question is: how much longer can we get away with such wasteful behavior?

One of Paulo Coelho’s passages from his book The Winner Stands Alone exactly describes my attitude and desire to “go green.” My heart pounds as I read the sentences that so touched me:

It seems now that-despite wars, famine in Africa, terrorism, the violation of human rights, and the arrogant attitude of certain developed countries-our main preoccupation is saving poor planet Earth from the many threats created by human society. “Ecology. Save the planet. How ridiculous.”

Hamid knows, however, that there’s no point in fighting the collective unconscious. The colors, the accessories, the fabrics, the so-called charity events attended by the Superclass, the books being published, the music being played on the radio, the documentaries made by ex-politicians, the new films, the material used to make shoes, the new bio-fuels, the petitions handed in to members of parliament and congressmen, the bonds being sold by the largest of the world banks, everything appears to focus on one thing: saving the planet. Fortunes are made overnight; large multinationals are given space in the press because of some completely irrelevant action they are taking; unscrupulous NGOs place advertisements on the major TV channels and receive hundreds of millions of dollars in donations because everyone seems obsessed with the fate of the Earth. Whenever he reads articles in newspapers or magazines written by politicians using global warming or the destruction of the environment as a platform for their electoral campaigns, he thinks:

“How can we be so arrogant? The planet is, was, and always will be stronger than us. We can’t destroy it; if we overstep the mark, the planet will simply erase us from its surface and carry on existing. Why don’t they start talking about not letting the planet destroy us? Because ‘saving the planet’ gives a sense of power, action, and nobility. Whereas ‘not letting the planet destroy us’ might lead to feelings of despair and impotence, and to a realization of just how very limited our capabilities are.” 3

On that note I would like to share some amazing facts I found while searching articles written on bacterial biopolymers, but first of all I would like to introduce some definitions on the concepts I will be writing about.

Plastics have many definitions, but usually, in a daily conversation, plastics mean “anything that can be molded or shaped.” Scientifically, a plastic is a sub category of a polymer. Poly- meaning “more than one” and -mer meaning “member of a particular group.”[4] Basically, a polymer is a naturally occurring or synthetic compound made of many relatively simple repeating units that are linked together in the same fashion, forming a carbon rich backbone in most cases. For example, PVC is a well known synthetic polymer, in which the monomer (the repeating unit) as seen in Figure 1 is repeated several times. A well known natural polymer is cellulose, in which the monomer as seen in Figure 2 is repeated several times.

Here it is important to note the difference between a polymer and a plastic. All plastics are polymers, as in the example of PVC, whereas not all polymers are plastics, as in the example of cellulose. The combination of the chemicals, and the type of bonds these chemicals are linked to each other by, determines the properties and applications of the polymers. The molecular weight of the polymer depends on how many times the monomer repeats itself. The molecular weight of polymers can be controlled during production with chemical techniques. One significant difference between natural vs. synthetic polymers is the molecular weight distribution. When the polymer is synthesized in the lab, the polymer product is a combination of different molecular weight chains. In other words, when a polymerization reaction takes place, lots of polymer chains are produced and one chain is never the same length or weight as another. Instead, there is a molecular weight distribution as seen in Figure 3, where most of the polymer chains in the solution have a molecular weight close to the value of Mw. So in the solution, we will have polymer chains that have molecular weights close to each other, and some extreme short or long polymer chains. It is impossible to synthesize a polymeric solution where all the polymer chains are of identical length and weight; therefore, we speak about the average molecular weight when the case is synthetic polymers. However, when we look at any polymer produced in nature, we see that the polymer chain length and molecular weight are the same every time the polymer is produced. So instead of a molecular weight distribution, natural polymers have a molecular weight value. This is important because the narrower the molecular weight distribution is, the better.

When talking about bio plastics, it is important to make the differentiation between bio-derived plastics and bio-based plastics. As Dr. R. Narayan explained in his talk at Johnson County Community College[5] , bio-derived plastics means that the plastic is isolated from a living organism, meaning that the living organism performs the polymerization reaction and then you extract the polymer from the organism.

On the other hand, bio-based plastics mean that the starting material of the plastic is derived from a living organism instead of a petroleum-based material, but it is polymerized into a plastic by humans. Therefore, not all bio-based plastics are biodegradable; however, the fact that the starting material is from a plant that can be replaced in a couple of years rather than a petroleum-based product which can only be replaced after a couple million years, drives motivation for their usage. There is the ethical concern that bio-based plastics are usually made from food sources, such as corn, however Dr. R. Narayan, who is one of the leaders in the field, argues that if the situation is handled appropriately, this should not be a problem. He argues that one up-side of the situation would be to increase values of crops and the prevention of mass migration to big cities. It’s your call to decide which side you favor more.

What is more interesting to me is the polymers being created in nature. A chemistry doctorate, Dr. Lon J. Mathias, writes that “We humans make nylons in tons per day in huge chemical plants where simple molecules are joined together in large quantities to give products that we need or want. Nature is much more careful and concise in how she does things. For a living organism to make an enzyme, another enzyme or active species must be involved. The synthesis always involves a template, or recording, of how the individual amino acids are to be joined together to give the final polymer. The enzyme adds a single amino acid, one at a time, as indicated by the mRNA. This is a slow and tedious process and takes a long time. Sometimes the enzyme gets frustrated, waiting for the right amino acid to come along, and slaps a wrong one on instead. To compensate for this, the enzyme is made to back up occasionally to check its work. If it has made a mistake, it has a process for clipping out the wrong amino acid and inserting the right one. We humans never do this. If we make a mistake, we simply grind it up and throw it away.”6

Dr. Mathias goes on, comparing the manufacturing conditions between nature’s form of polymerization and humanity’s. He says polypeptides in nature are synthesized in water, whereas we synthesize our polypeptides in toxic organic solvents. “This leads us to a problem: what do we do with the organic solvents when we’re through? Sometimes we burn them, but more commonly we try to recycle these materials, which not only are getting more expensive to buy in the first place (compared to cheap water, which is everywhere, or almost everywhere) but are also a responsibility for their recycling, purification, and final disposal. An example of how nature uses water in this way, and one which we still haven’t figured out, is the production of spider silk. Spiders spin their webs from solutions of polypeptides in water. These solutions are squeezed through the spider’s tiny spinneret and elongated quickly to form the spider webs which we’ve all seen and sometimes become tangled in. What’s really weird is that, once these spider webs form, they are no longer soluble in water. If we could just figure out how spiders first make spider silk in water and then spin their webs from it, we could make nylon the same way. This might save us a lot of waste disposal problems, and money.”6

Another spectacular creation in nature is polymers produced in bacteria which can be used as plastics once isolated from the bacteria. A wide range of biopolymers that are synthesized in bacteria serve diverse biological functions and have material properties suitable for numerous industrial and medical applications.7 Different carbon sources are efficiently converted into a diverse range of polymers with varying chemical and material properties.7 To be a little more specific, four major classes of polymers are produced by bacteria: polysaccharides, polyesters, polyamides and inorganic polyanhydrides (such as polyphosphates).7 These polymers serve various biological functions, for example, as reserve material or as part of a protective structure, and can provide a substantial advantage for bacteria under certain environmental conditions.7 Some of these biopolymers can be isolated from bacteria and can be used as plastic. Biopolymers are, by definition, biodegradable, and so their application as commodity products becomes increasingly attractive in view of the desire to avoid the use of recalcitrant oil based polymers that will accumulate in the environment.7 Biodegradable means that when exposed to the microbial flora present in a given environment (for example, in soil or water), biopolymers are fully degraded and mineralized to CO2 and H2O.5 The reason biopolymers are 100% degradable is, as they are produced in bacteria as storage material, they have sites where bacterial enzymes could attack to break them down when they search for nutrients. Whereas other polymers – even bio based polymers – will not have these enzymatic sites, so they are not always biodegradable.

One popular class of polymers produced by bacteria which can be used as plastics is called polyhydroxyalkanoates (PHA’s). PHA’s are a class of polymers produced in nature by the bacterial fermentation of sugar or lipids. They are produced by bacteria to store carbon and energy when there is a nutrient lacking from the environment. Many kinds of bacteria are able to produce PHA’s, such as soil inhabiting bacteria, and many bacteria in activated sludge, high seas, or extreme environments. 8 As we store fats in our bodies, the bacterium store PHA’s. In an environment that contains all of the necessary nutrients, bacteria grow and reproduce – in other words they produce biomass. However, when subjected to specific nutrient depletion (nutrients such as nitrogen or phosphorus) and excess amount of carbon resources, the bacterium starts storing PHA granules (Picture 3). The moment the missing nutrient is introduced back into the environment, the bacterium starts degrading the PHA granules and continues to produce biomass. Therefore, by manipulating the nutrient resources in the environment and providing optimum conditions, bacterium can be pushed to produce PHA’s.[9]

There are metabolic pathways involving various enzymes for the conversion of carbon sources to polymers. Scientists have been trying to genetically engineer bacteria for the increased production of these polymers. In some cases it is possible to over-express the key enzymes in the pathways to achieve increased production of PHA. However, this kind of research takes a lot of time and effort because altering biological activity is a very complicated process and in most cases, cells give unpredictable responses to alterations. By feeding the bacterium with different carbon sources at different conditions, it is also possible to alter the composition of the polymers. Moreover, different strains of bacterium produce different types of polymers; therefore, the range of biopolymer research is very wide. With over 150 different PHA monomers (the repeating unit of polymers) being reported, PHA with flexible thermal and mechanical properties have been developed. 7 Such diversity has allowed the development of various applications.

During his speech at the “2nd International PLASTiCE Conference Trends in Bioplastics” in Slovenia, 9 Dr. Martin Koller explained that there are two types of PHA’s that a microorganism produces. The first type are short length PHA’s (3-5 carbons in the backbone) and the second type are medium chain length PA’s (6-12 carbons in the backbone). While the medium chain length PHA’s can be used for biodiesel production, the short chain length PHA’s can be used as thermoplastics (plastics that can melt with heat, and can therefore be processed with the help of heat). These thermoplastics can be isolated from the organisms they are produced in by solvent extraction, mechanical disruption, or by using hypotonic media (having the lower osmotic pressure of two fluids) for cells that have high intracellular osmotic pressure.9 In the last case, the cells will explode due to the pressure difference and release the PHA’s; deionized water can be used as the hypotonic media. However, only specific strains can be treated with this method. At the moment, the most common technique used for extraction is solvent extraction. These solvents – such as chloroform or dichloromethane – are generally toxic, therefore creating a contradiction with the point of producing biopolymers.

Although not mainstream, some of these bacterial plastics are produced in the industrial world.8 The simplest and widest application for bacterial plastics is for packaging purposes. They can also be used in therapeutic applications, as they are generally biocompatible. Drugs can be incorporated into them, therefore as they biodegrade, they release the drug in a controlled time frame.9 For example, Dr. Martin Koller and his group have just finalized a project called “BRIC – BioResorbable Implants for Children,” funded by the Austrian Research Promotion Agency (FFG).10 Their purpose was to isolate a biocompatible polymer produced from bacterium which could be degraded and removed from the body within a certain time. The point of this project is based on the fact that in contrast to the traditional implants that need to be removed from the body after a certain amount of time, such as plates, screws or pins, the newly developed implants could be degraded and removed from the body naturally, preventing the need for a second surgery. This is a great advantage, especially for children, who would suffer greatly from additional surgeries.

Bacterial bioplastics have many other applications; however the biggest obstacle for their usage is the cost of production. During his speech, Dr. Keller stated the production of bacterial bioplastics is around five times more costly than petroleum based plastics. Most of the cost is related with the bioreactors needed to grow the bacterium and the solvents used to extract the polymers. The scientists are hoping to develop new techniques to reduce the cost of the polymers.

It is breathtaking that these creatures we cannot even see with the naked eye have been synthesizing polymers as well as we do, if not even better, and for a lot longer than us. The polymers they synthesize are completely biodegradable, have a constant molecular weight, and do not require toxic chemicals for their production, unlike the synthetic polymers we produce in the lab. They don’t harm nature as we do. And THAT is powerful.

References

1- Simon, Tristan (2007). “Experience Curves in the World Polymer Industry” Utrecht University, Netherlands.

2- Lei Pei, Markus Schmidt and Wei Wei (2011). “Conversion of Biomass into Bioplastics and Their Potential Environmental Impacts, Biotechnology of Biopolymers.” InTech.

3- Coelho Paulo(2008), “The Winner Stands Alone.” pg: 139.

4- http://dictionary.reference.com/

5- Narayan, Ramani (2013)”Bioplastics and Reducing Carbon Footprint.” JCCC Video. Johnson County Community College, USA.

6- Mathias, Lon J. (2005).”Natural Polymers.” Polymer Science Learning Center. The University of Southern Mississippi, USA.

7- Rehm, Bernd H.A.(2010). “Bacterial polymers: biosynthesis, modifications and applications” Nature Reviews Microbiology. Massey University, New Zealand.

8- Chen, Guo-Qiang (2010). “Plastics Completely Synthesized by Bacteria: Polyhydroxyalkanoates”. Plastics from Bacteria: Natural Functions and Applications, Microbiology Monographs, Springer. Tsinghua University, China.

9- Koller, Martin (2012). “Polyhydroxyalkanoates: Biodegradable polymeric materials from renewable resources” Plastice Project Video. 2nd International PLASTiCE Conference Trends in Bioplastics, Slovenia.

10- No name (2013).”Plastics from Renewable Raw Materials:Body automatically breaks down implants” Graz University of Technology, Austria.

11- Nishiyama, Yoshiharu; Langan, Paul; Chanzy, Henri (2002). “Crystal Structure and Hydrogen-Bonding System in Cellulose Iβ from Synchrotron X-ray and Neutron Fiber Diffraction”. J. Am. Chem.The University of Tokyo, Japan.

12- Ritter, Stephen(2005). “Green Success.” Science and Technology. pg: 40-43.

13- Waters Co. (2013). “GPC-Gel Permeation Chromatography”. Web.

Elephants can determine ethnicity, gender, and age from acoustic cues in human voices. McComb et al. February 2014, PNAS.

African elephants (Loxodonta africana) are the largest land animals on Earth and they have been facing the danger of extinction due to habitat loss and illegal hunting for their ivory tusks. Elephants are also known to be very intelligent creatures and a recent study showed that they can even differentiate between human languages. Researchers at Amboseli National Park in Kenya played two different recordings of human voices for elephants. One group of voices belonged to local Maasai men, who happen to have violent encounters with elephants from time to time while herding their cattle. Other voices belonged to Kamba men, who are farmers or employees of the national park, and usually pose no threat to the elephants. In both cases, researchers played the same phrase, “Look, look over there, a group of elephants is coming,” in two different languages. When elephants heard Maasi voices, they demonstrated defensive behaviors, such as gathering together, investigative smelling through their trunks, and moving cautiously away from the stimuli. Interestingly, elephants showed a greater reaction to the voices of Maasi men than Maasi women or boys, suggesting that they can even differentiate the gender and age of humans. In contrast, when they heard Kamba voices, of any gender or age, they did not show any concern. Ability to recognize predators is a crucial skill for many animals, and elephants seem to be capable of pinpointing the ethnicity, gender, and age of a potential predator, perhaps through recognizing acoustic cues in human voices. This ability serves as an early warning system for elephants and it could become very useful, especially when the predator is out of sight.

Set your alarm early to control weight

Timing and intensity of light correlate with body weight in adults. Reid JK et al. February 2014, PLOS ONE

Early sunlight exposure in the morning has been found to lower a person’s body mass index (BMI). A recent study showed that 20-30 minutes of morning light controls approximately 20% of the variation in a person’s BMI. This effect was independent of physical activity, caloric intake, sleep timing, age, or season. Our bodies have an internal body clock called the “circadian clock.” It roughly controls 24-hour cycles of physical, mental, and behavioral activities. Light is the most potent regulator of our circadian clock. It sends strong signals to our brain and body, which in turn regulate our energy balance and metabolism. Previous studies showed that animals with an altered circadian clock gain weight even though they don’t eat more. Similarly, new research with study subjects showed that missing out on the early rays of sun shifts our circadian clock and alters our appetite, satiety, and even the way that our body processes food, which ultimately leads to weight gain. In modern times, we live and work indoors, thus are often not able to get enough light in the morning. While the daylight is the best source, experts think that standing by the windows or even using a strong desk lamp would be sufficient to properly synchronize our circadian clock in the morning.

Mystery of zebra stripes solved

The function of zebra stripes. Caro T. et al. March 2014, Nature Communications

The black and white stripes of zebras have intrigued people for centuries. Scientists have speculated many hypotheses for the purpose of these stripes, such as camouflage, heat management, social implications, etc. A new systematic study analyzed 7 different equid species with stripes on their bodies and mapped their geographic locations. Then, researchers generated a statistical model by comparing the stripe patterns of these animals and their environmental conditions. Strikingly, they discovered a clear overlap between the range of striped animals and where biting flies, like horseflies or tsetse flies, are highly populated. Scientists noticed greater striping among animals in regions where there were more flies. These results suggest that having stripes may protect zebras from biting flies. Zebras, unlike other African hooved mammals living in the same area, are particularly susceptible to biting, as their hair is shorter than the pinchers of the biting flies. A separate work has shown that some flies tend to avoid black-and-white striped surfaces, supporting the hypothesis that biting flies may avoid the striped surfaces of zebras. As much as these results are encouraging, no one actually observed zebras in the wild to see if biting flies avoid landing on them, in part because it’s almost impossible to stay that close to zebras. The next challenge for the researchers is to observe this phenomena live in the wild.

The Earth’s shape is becoming rounder as a result of the construction of projects like the Three Gorges reservoir. The weight decrease due to the melting icecaps has played a major role in these changes.

From time immemorial, humanity has wondered about the shape of the Earth. Over the centuries countless studies exploring the Earth and its shape have been conducted, and they still continue today. With advancements in technology, the methods and measuring devices have constantly changed. In earlier periods the Earth was believed to be flat; nevertheless from around the fifth century bc there were varying opinions suggesting that the Earth was actually round and calculations were conducted to measure its radius. Particularly from the seventh century ce onwards, the number of studies regarding what the Earth really looked like have increased tremendously.¹

In later years, with the advent of Islam and its open encouragement of Muslims to explore the universe and make advances in science, Muslim scholars made huge progress in astronomical research. Historians who have studied these advancements in astronomical science agree that the era between the eighth and fourteenth centuries can aptly be designated as a period of Islamic astronomy. In the years following the sixteenth century, significant research was undertaken in relation to the shape of the Earth and measurements of its radius in both the Islamic world and the West.

In the eighteenth century astronomic research and the advancement of technology proved not only that the Earth was round, but that it had a distinctive shape. According to calculations, the Earth was bulging around the equator and flattened at the poles. The maps produced by satellite systems show that the Earth is not completely round or smooth, but rather it has protrusions, creating an uneven surface that resembles a face with spots.2

“Geoid” is the term scientists prefer to use when referring to the physical depiction of the Earth’s surface. The shape of the Earth is not a perfect ellipsoid, thus, scientists use this representative surface that is thought to be most approximate to sea level, in order to identify departures from the ellipsoid shape. Due to the events of nature and human-related factors the geoid constantly changes, and this is why a precise mathematical account of the geoid has not yet been possible.

The Earth is known to be a geologically active planet. Just as everything else in the universe, from atoms to galaxies, has not been left to their own fate, the Earth is also constantly being transformed, thus making our magnificent ecosystem possible. The continuous geological process of changes in the Earth’s crust is related to a variety of factors: the varying density of the rock layers which form the Earth’s crust, the activity of the tectonic plates, as well as the movement of the continents, shifts in the center of gravity, tidal activity, hydro-spherical and atmospheric phenomena, and human intervention in some regions.

Researching the variations in the gravity of the Earth with satellite systems is a relatively new method of recording the changes in geoid elevations. The distance between the center of the Earth and its surface is constant (the tallest mountains will rise or decrease 1-2cm per year at most); if we take into consideration that the Earth’s physical body does not vary much and disregard the other forces, then we can say that the main reason for these infinitesimal changes in gravity on the surface of the Earth is due to differences in mass. While there is a decrease in weight in specific regions from melting glaciers, in other areas there is an increase in weight due to melting water flowing into reservoirs; both these phenomena play a significant role in the variations of the Earth’s gravity.

Even a minor variation in mass can be detected by measuring gravity. The change of mass location on the Earth’s surface results in gravity variations in the same region; in brief, today the commonly used gravity measurements are the most important source for detecting and identifying variations in geoid elevations, as well as determining the actual reasons for these changes. Gravity measurements are conducted via satellite systems; these indicate changes in mass location by detecting an increase or decrease in weight. The most modern technological satellite systems that can detect gravity change and allow us to follow the variations in masses on the Earth’s surface are the satellite used by the European Space Agency, called GOCE, and NASA’s satellite, called GRACE. GOCE has been designed to perform accurate studies of the Earth’s gravity field as it progresses into orbit. As the satellite passes over the regions where gravity is intense or weak, it measures the variations in gravity with signals that have been conveyed by a device called a gradiometer. GRACE is a pair of identical satellites that are flying in the same orbit, 136 miles apart; they orbit the Earth at a distance of 300 miles. These satellites can measure distances with microwave signals, and can detect changes of less than 1% the thickness of human hair; thus the twin satellites are able to accurately measure the distance to the surface of the Earth. The measurements provided by this satellite system make it possible for changes in gravity to be calculated. The GRACE satellite data is 1,000 times more accurate than other gravity field detection systems.

The enormous waves that occurred on the sea surface as a result of the Sumatra Island earthquake, which measured 9 on the Richter scale, caused a level ridge, measuring about six meters in height, to form on the shore. According to data produced by GOCE, such changes in the mass of the Earth’s surface caused a variation of 18 mm to occur on the geoid; this is recognized as a relatively high degree of change.

Changes in the polar glaciers also cause variations in the geoid; data provided from satellite GRACE shows that the layers of ice in Greenland and the Antarctica are melting at a higher rate than previously expected. The melting icebergs are causing a rise in sea levels of up to 0.41 mm every year and the weight of water produced from the melting icecaps is causing changes to the shape of the Earth’s surface.3

One of the interesting facts attained by GRACE is the changes in the Earth’s gravity field that have been caused by Three Gorges in China, the largest reservoir ever built. The lake region of the reservoir that is being built measures around 372 miles long, 70 miles wide and approximately 574 feet deep; when the casing of the reservoir is completed it will house an amazing 39.3 billion m3 (9.4 cu mi) of water. The area that this reservoir will cover once the project is completed is so great that it will make an estimated 1.5 million people homeless. It has been observed that the enormous accumulation of water in the completed sections of the reservoir has increased the gravity level in that region, which in turn has caused changes in the geoid structure.4

Scientists have confirmed that the Earth’s shape is becoming rounder as a result of the construction of projects like the Three Gorges reservoir. It is also estimated that the weight decrease due to the melting icecaps has played a major role in these changes. In some regions of Scandinavia and Canada the ground is rising 1 cm every year due to the melting glaciers. The water produced from the melting glaciers is forcing the currents in the Atlantic Ocean towards the equator, while the decrease of mass at the poles and the increase of weight in the equator region have caused significant changes in the shape of the Earth.

Many scientists claim that changes in the Earth’s surface have been caused by changes in the climate. Unfortunately, according to a report published by the UN Intergovernmental Panel on Climate Change (IPCC), humans are responsible for 90% of global warming. As a result of these vast variations, the geoid shape of the Earth is becoming rounder and its radius is increasing annually by 0.4–0.8 mm. The reasons for these changes are being closely monitored by scientists. According to scientists, the variation of the geoid that has been caused by changes in mass location is having an effect on the Earth’s dynamics, with the transfer of mass demonstrated by the changes in gravity causing a reduction in the speed of the Earth’s rotation around its axis; this is expected to result in variations in the daily time-zone.

Abdullah Sancak is pursuing an academic career in engineering in Turkey.

Notes

1. For more information on this topic see James R. Smith, Introduction to Geodesy, The history and Concepts of Modern Geodesy, John Wiley and Sons, Inc., 1997.
2. There are interesting images that show how the earth looks in the following link: University of Texas Center for Space Research and NASA (7 Haziran 2005) http://www.csr.utexas.edu/grace/gallery/gravity/
3. G. Ramillien, A. Lombard, A. Cazenave, E. R. Ivins, M. Llubes, F. Remy, R. Biancale, Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE, Global and Platenary Change 53 (2006) 198-208.
4. San Shaoan, Institute of seismology, CEA, Wuhan, China, Gravity change before and after the first water impoundment in Three Gorges Project. http://www.sgg.whu.edu.cn/icct/html/icct_ppt/S1/sun.s.A___fourth.pdf

Birds, class Aves, are the only animals that have feathers. Aves is a large, highly diverse class with 8,600 species of water birds, songbirds, and birds of prey, including huge flightless runners, deep divers, and migratory species that travel thousands of miles each year. Although most birds have similar body structures, taxonomists, those who classify and name things such as animals and plants in groups, use variations in bone structure, muscles, and internal organs to distinguish one order from another. Variations in the shape and structure of the bills, wings, tails, and feet are also useful for classification and identification. Birds inhabit a wide variety of habitats and can be found on all the continents, most islands, and even on the open sea. They also have a wide range of size. The largest birds are the ostriches of Africa, up to 2m tall and weighing 136kg, and the great condors of the Americas, with wingspreads of up to 3m. The smallest known bird is Helena’s humming bird of Cuba, less than 6cm long and weighing less than 4g.

The skeleton system of birds is highly adapted for flight. In spite of its low weight, a bird’s skeleton is extremely strong. Hollow and fused bones are the two main bone types. Most bones` being hollow lessens overall body weight making flight more efficient. The skeleton of a bird is much lighter than any other kind of warm-blooded animal. However, this is achieved at a cost, and the skull of a bird is thin and susceptible to fracturing. Further lightening of the bird`s head has also been made possible by the absence of teeth. The other noticeable feature of a bird’s skull is the size of the eye sockets, to house the large eyes. This is probably because vision is a bird’s most crucial sense. The skeletal structure of the wing is relatively constant among the different species, but the actual shape of the feathers can be quite variable, depending on the flying capabilities of the species concerned. To provide effective thrust, the bones in the wing move together. As the bird’s wing beats downwards, special bones prevent its chest from being crushed. The thrust of the wing articulates with the scapula on each side of the body. The corocaid and the wishbone also provide reinforcement. The chest cavity is reinforced by the unusual structure of the ribs. The ribs have projections, known as incinerate process, which are directed backwards, overlapping each other. These help to provide support, especially in diving birds. In cross section, the wings are honeycombed. During flight, this lightens the load on the pectoral muscles which, attached to the keel of the sternum, may account for half of the birds body weight.

Flight is one of the most outstanding characteristics of birds. A bird’s body is adapted to meet the two major requirements for flight, which are low weight and high power. Unlike other vertebrates a bird has a skeleton that is very light in relation to body size, e.g. a pigeon’s skeleton accounts for only 4.4 per cent of its body weight. Birds have a compact, streamlined body, and the fusion of many of the bones gives the body the rigidity needed for flying. A birds wing bone is thin and hollow, with criss-cross reinforcements on the inside which provide support while adding little weight. Besides the unusual structure of bones, it is the presence of feathers that distinguishes birds from all other creatures that have conquered flight. Feathers are made of dead cells, and become dehydrated and are exceedingly light. Thus, they can be large and form the flight surface of the wings and tail without weighing much and without being susceptible to water or heat loss. Along with keeping a birds body warm, feathers function for flight. The long overlapping contour feathers streamline the body. These feathers form the wings and much of the tail. Wings made of contour feathers have much surface area and little weight. They are well adapted for fanning the air and for gliding on air currents.

The flight of birds is one of the most beautiful and wonderful things in nature. The make and arrangement of their feathers and bones, and their stream-lined shapes, from beak to tail, are instances of purposive adaptation. They soar with outstretched wings; they dart with folded wings. Their upward and downward mobility, as well as their stability in the air, and when they rest on their feet, have given many ideas to man in the science and art of aeronautics, But who taught or gave to birds this wonderful adaptation? None but God, Whose infinite Mercy provides for every creature just those conditions which are best adapted for its life. This is stated in a verse in the Qur’an (Mulk, 67.19):

Do they not observe the birds above them, spreading their wings and folding them in? None can uphold them except (God) Most Gracious: truly it is He that watches over all things. 

Flying techniques depend on the principles of aerodynamics. Reducing air pressure and friction against the body requires perfect aerodynamic structure. Up to recent times, a rain drop was accepted as the most perfect aerodynamic shape. However, the shape of a bird’s body is now accepted as the most perfect, and aircraft are designed according to the aerodynamic structure of birds. Compared with birds, the latest aircraft are still clumsier and have less agility than birds. Moreover, hypoxia, which is a deficiency of oxygen and results in drowsiness, mental fugitive, headache, and sometimes euphoria, affects pilots severely and can cause them to lose their consciousness on flying upward. But this is not a hindrance for birds because the air between their feathers, their bodies and wings is absorbing and reducing air pressure, Along with this ability, there are some movements which birds can do easily, such as turning sharply, doing somersaults, steep ascents and descents, whereas manmade flying machines face some serious risks in attempting the same movements. Birds can also glide for long periods without beating their wings while aeroplanes cannot sustain flight with stopped engines. Vertical take off and landing is something many flying animals such as bees and birds have been able to do for millions of years. The structure of birds has inspired engineers to design specific modifications in recent models of aircraft, such as the F-14, F-18, and M1G-25, It is true that producing an aircraft requires complex skills and knowledge, improved steadily over a long time. But is it not marvellous that birds have been demonstrating perfect flight for millions of years?

Birds have become adapted to a variety of environments, and various species have very different types of beaks, feet, wings, tails, and behavioural patterns. Although all birds must eat frequently (because they do not store much and yet must maintain a very high metabolic rate), their choice of food varies widely among species-seeds, fruits, worms, molluscs, rodents, rabbits, fish, snakes, lizards, even dead animals. The shape of the bills reflects the birds feeding habits. For example, nectar-feeders have narrow, pointed bills; finches, which consume large quantities of seed, have short, stout bills; and birds that eat insects and berries have a non-specific bill shape and so on.

Birds also lack teeth and this probably reduces body weight for flight. Instead of teeth, their mouths are modified into bills. In addition to this modification, birds have another adaptation for digesting food. A bird swallows small bits of gravel, which act as teeth in the gizzard, mechanically breaking down food. An interesting feature of the bird’s digestive system is the crop, an expanded, sack-like portion of the digestive tract below the oesophagus, in which food is temporarily stored, and where food such as hard seeds is softened with mucus. As a storage organ, the crop allows the bird to feed rapidly and to store large amounts of food. The bird also produces a white secretion, sometimes called crop milk’, which is rich in proteins and fats, and birds use this secretion to feed their young. Birds (except for the ostrich) do not possess a bladder, and so the uric acid passes directly, through the uretors, to the cloaca. After reabsorbing water back into the bird’s body, uric acid is excreted in the form of a semi-solid, whitish concentrate.

Birds often build up high concentrations in their bodies because they consume salty foods or sea water and lose water through evaporation in the urine and feces. To rid themselves of this excess salt, these animals have salt glands, special secretary organs near the eye or in the tongue that remove excess salt from the blood and secrete it in a solution of tear-like drops. Sensors in the wall of a bird’s heart apparently monitor the osmotic pressure of the blood and send nerve signals to the brain that trigger activation of the salt glands. Thus, the animal can drink sea water and yet, by excreting some of the water and all the salts, achieve a net water gain. This is an adaptive mechanism that helps to maintain a light body weight.

Birds have a well-developed nervous system with a brain. They rely heavily on vision; their eyes are proportionately larger than those of other vertebrates. Hearing is also well developed, in striking contrast to most animals, birds have developed the voice. The spoken word in human speech is different from the means of communication which birds have between each other. But no man can doubt that they have means of communication with each other, if he only observes the orderly flight of migratory birds which live in communities. This is also stated in the sacred book, Qur’an (al-Naml. 27.16):

And Solomon was David’s heir. He said: ‘O ye people! We have been taught the speech of Birds, and on us has been bestowed (a little) of all things.’ this is indeed Grace manifest (from God.)

Most birds have short simple calls that signal danger, or that influence feeding, flocking, or interaction between parent and young. Songs are usually more complex than calls and are performed mainly by males; they are related to reproduction, attracting and keeping a mate, claiming and defending territory.

Birds have a special system of air sacs that make fresh air almost continuously available to the sites of gas exchange. This provides the animal with the large quantities of oxygen needed for long distance, high- altitude flights — even a flight over Mt. Everest. A bird’s many air sacs also lower the body weight relative to its size. Air sacs lying between certain flight muscles are squeezed and relaxed on each stroke of the wing and this helps increase the amount of air during inhalation and exhalation. The faster the bird flies, the more rapid is the circulation of air through the lungs.

The paired lungs are relatively small and nine or more hollow air sacs are attached to the lungs and fill much of the body cavity. They are like balloons that lighten the body and serve as reservoirs for air that will later be needed. Experiments show that air flows continuously during both inhalation and exhalation, in one direction through the lungs, and the air is renewed during each inspiration. Therefore, oxygen and carbon dioxide exchange occurs in the lungs’ air capillaries during both inhalation and exhalation. The direction of blood flow in the lungs is opposite to the that of air flow through the parabrocni, tiny, thin-walled ducts in the lungs. This counter current flow increases the amount of oxygen that enters the blood.

This system enables birds to do the intense work of flying, even at high altitudes, and still maintain a high body temperature. Interestingly enough, rapid breathing also contributes to such a high performance; a Venezuela hummingbird, the sparkling violet ear, breathes 330 times per minute at sea level and 380 times per minute at high altitudes. This is a very high heart beat such as no other warm-blooded animal can accomplish.

The very effective respiratory and circulatory systems provide enough oxygen to the cells to permit a high metabolic rate. This is another important adaptation of birds: the maintenance of a high and constant body temperature in spite of changes in the external environment. High metabolic rate is necessary for the tremendous muscular activity required for flying. Some of the heat generated by metabolic activities is used to maintain a constant body temperature (between 35 and 42 degrees C) which permits birds to remain active in cold climates. Birds are among very few animals able to maintain a constant body temperature. Though birds are sometimes called warm-blooded, the preferred term is homeothermic.

One of the most interesting types of behaviour in birds is migration. Migration is the instinctive movement of animals, usually between their wintering grounds and their breeding grounds. Migration provides birds a better chance of surviving. By instinct, migrating birds make their long journeys each year to reach more favourable habitats. Some birds, such as the golden plover and arctic tern, fly from Alaska to Patagonia, South America, and back each year, flying 25,000km en route.

Migration is probably set in by several external stimuli, such as temperature and length of daylight. It is also triggered by the secretion of hormones. For many species the direction of migration is probably based on such factors as the bird’s observation of the sun and stars and even by the earth’s magnetic field. Few modern biological discoveries have been more surprising than the finding, in the 1970s, that bird’s, bacteria, and perhaps many other types of organisms orient their bodies to the earth’s magnetic field, How such animals can have acquired this magnificent ability is a question yet to be answered. How can living things perceive a force as elusive as magnetism?

Many birds and at least one mammal-the porpoise-have a small number of tiny crystals of magnetite (a form of iron oxide) in tissues near the brain. Likewise, magnetobacteria, have magnetite crystals in their cytoplasm and swim toward or away from the poles of an applied magnetic field. How some higher organisms use magnetic particles to sense the direction of the lines of magnetic force generated by the earth’s core remains a subject of research. One hypothesis suggests that the crystals in, for example, a pigeons head, function like tiny compass needless, and mechanoreceptors might detect their relative movement. Other work indicates that in the rat, changes in magnetic yield can alter enzyme activity and levels of melatonin in the pineal gland. Still other work suggests that regularly arrayed layers (also present in pineal glands) undergo certain changes as the head and eyes move relative to the earth’s magnetic field. They could allow the animal to sense magnetic fields, but not by a mechanoreceptor mechanism. Whatever the mechanisms, homing, migration and many other directional animal behaviours depend on detecting magnetic fields.

Birds with their perfect features are wonders in nature to be marvelled at as such. All creation, both animate and inanimate, celebrates Gods praise and bears witness to His power, wisdom and goodness. We can aspire to true knowledge of God through observing the wonders in nature. However, this is possible only if people do not insist on their positivistic viewpoint and see the direct manifestations of God’s Names in His creation:

The seven heavens and the earth, and all beings therein, declare His glory: There is not a thing but celebrates His praise. And yet you understand not how they declare His glory! Truly, He is Off-Forbearing,’ Most Forgiving! (Bani Israll. 17.44)

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’.