Research on hummingbirds (also known as nectar birds or Colibris), the smallest of the 9,800 bird species living today, has revealed remarkable facts. The world’s smallest birds are equipped with mind-blowing structures and functions that push all physiological and anatomical boundaries. The bee hummingbird (Mellisuga helenae), considered to be the smallest bird in the world, is only 1.96-inch-long and weighs 0.06 ounces.

There are around 330-340 species of hummingbird and they live only in North and South America and the nearby oceanic islands. With their colorful feathers, they are some of the most beautiful birds.

How the hummingbird flies

A hummingbird flaps its wings so fast that the motion cannot be seen by the human eye but only detected through special cameras. The wings move at an incredible speed in a seemingly complex pattern, drawing circles back and forth 50 to 80 times per second, depending on the species. Under the genus Colibri, the horned Sungem (Heliactin bilophus) species flaps its wings 90 times per second; the purple amethyst Colibri (Calliphlox amethystina) flaps its 80 times per second. This speed increases up to 200 per second during a short spike while escaping from an enemy. Moving back and forth, the wings oscillate in the form of the figure 8 in the air. While in most other birds the movement of the wings produces the power to lift up and down, Hummingbirds, like helicopters, can perform movements such as hanging in the air or standing steadily as well as flying backward or rising in a vertical direction.

Figure 8

Metabolic rate and energy consumption

Flying requires a lot of energy. The amount of energy spent is related to the bird’s body size and flapping speed. In this regard, given that a colibri flaps its wings 80 times per second, it takes a great deal of energy to maintain such a rapid movement. The colibri’s chest muscles were perfectly created for flapping quickly and take up 40% of the hummingbird’s total body mass. Therefore, a colibri consumes more energy than other birds; it’s basically a fighter jet.

In order to meet this high energy demand, the amount of nectar a colibri consumes every day has to be equal to their body weight. Living at such a high metabolic rate requires a fine adjustment of food consumptions with precise calculations.

Such a high food intake requires a high metabolism – and thus, the need for oxygen increases dramatically. When the need for oxygen increases, there can be two kinds of conditions. Those animals with very large lungs can intake a lot of air at once. And those with smaller lungs can produce the required oxygen by breathing many times a minute. Colibri or Nectar birds are the ones that can breathe the most in one minute. The lungs of the world’s smallest birds breathe 250 times per minute to transfer oxygen to their hearts weighing a mere 0.003 ounces and beating 1,200 times per minute.

Toronto University’s Kenneth C. Welch Jr. studied the metabolism of hummingbirds for more than 10 years. He discovered that there is a relationship between the size of hummingbirds, energy efficiency, and oxygen consumption, and that larger hummingbirds are more efficient energy users than smaller ones. A hummingbird can take 2.44 cubic inches of oxygen per 0.03 ounces an hour. When a small weight is added to the bird, this amount increases to 3.66 cubic inches, and their tissues use oxygen very efficiently.

Energy requirements

A hummingbird’s metabolism is the fastest among all vertebrates. It needs to eat almost constantly to get the energy it needs to produce fuel for its breathtaking metabolism, which functions like a power plant. It receives nectar from 2,000 flowers every day. If we humans could work at this bird’s energy levels, we’d have to eat about 1,300 sandwiches a day to produce energy, and our body temperature would rise to 725 °F! Also, our hearts would have to beat 1,260 times per minute. Although nectar from flowers is the main fuel source driving the bird’s metabolic engines, it also occasionally eats insects, for protein needs.

During any given 30-minute period, hummingbirds burn the sugar they had taken in an hour ago. If we apply this rapid intake of sugar and the metabolic cycle in human beings, we would have to drink a large bottle of soda and burn the sugar in it every minute.

Unlike us, hummingbirds use both glucose and fructose from nectar in their intestines, circulatory systems, and muscle cells. However, we can support our bodies at urgent needs with an intake rate of 30% of glucose. Half of the nectar that hummingbirds take is glucose and half is fructose. In this modern age, high fructose derived from corn in our diets has paved the way for metabolic diseases and obesity – that is, people cannot metabolize high fructose.

Scientists are trying to determine how hummingbirds can process fructose. It is known that there is a carrier molecule different from glucose in fructose. This carrier is very rare in human muscle cells, but it is found in abundance in hummingbird’s muscle fibers; so we believe the mystery of how they utilize fructose so fast is about to be solved.

Hummingbirds have been equipped with mechanisms to increase the rapid introduction of nutrients such as fructose and glucose – which are basically small sugar molecules – or amino acids into their metabolisms. Their hearts and blood vessels work at a high speed to carry the sugar into their tissues as well as to transfer a lot of blood. In addition, a large number of capillaries have been implemented close to the muscle cells so that the blood can reach each and every cell.

Wing design

While humanity has not yet invented a machine that can move in a figure-8 pattern 80 times per second, including forward and backward, the ultra-flexibility of a hummingbird’s unique wing strokes demonstrates the special creation of its bones, muscles, and joints. The colibri’s brain and nervous system, which control these muscles and joints by transmitting signals, require infinite knowledge and power. The flexibility of the shoulder joint in the movement of the wings, which allows them to bend to extreme positions not found in other birds, gives us an idea of the wing’s unique design and architecture. Although biomimetic engineers have spent millions of dollars applying this complex system to technology, they have so far failed in their attempts to produce a similar machine.

Cooling the feathers due to the friction of the muscles and the tremendous movement of the wings is a problem in itself. While man-made machines need advanced cooling systems, the hummingbird has been created with a such a built-in system.

Unique tongue structure

Biologists from the University of Connecticut have discovered that hummingbirds’ tongues have a very special design and work like micro pumps. Tongues about twice the length of their beaks allow them to reach deep into flowers. The nectar is then pumped into the body in less than 1/20^th of a second. This occurs thousands of times each day. Tai-Hsi Fan and Margaret A. Rubega, who for a long time examined how hummingbirds stick their tongues 15 or 20 times a second into the tubular part of a flower, said that they “could not clearly understand how they drink the nectar.” In their latest study, they showed that it was only possible for the birds to hold nectar through two channels in their tongues. It was once thought that the physical rule of the upward movement of liquids in capillary tubes, even without suction, worked in the hummingbird’s nectar intake; but when special video recordings of the movement of their tongues were examined, it became evident that the tongue first compressed the nectar in a series of movements, then sprung up very quickly and the nectar was suddenly sprayed into the channels.

It would seem that both the hummingbirds and the flowers they need for sustenance were created in perfect harmony.

Red hummingbirds migrate from Alaska to Mexico every year. They can fly 56 miles per hour. Prior to this journey, they feed for one or two weeks to fill their fuel tanks, forming a layer of fat equal to half their body weight. Since these activities cause a lot of heat loss on the body surfaces, they cannot provide enough energy to stay active for more than 12 hours at a time. To counter this, they fall into a deep sleep every night for 12 hours. The energy storage, flight endurance, long-distance migration, and returning with the young ones are each complicated factors that their coming together to make this journey possible cannot simply be explained by blind chance.

Of course, the smallest bird in the world would have the smallest egg size: a mere 0.5 x 0.3 inches, for a total weight of 0.007 ounces. Considering that this wonderful bird’s design is embedded into this egg, which is about the size of the nail of our little finger, it can be understood how perfect a creation it is.

A sugar is a monosaccharide if it is made up of a single sugar molecule; it is disaccharide if it is built by two sugar molecules; and a polysaccharide if it is composed with multiple sugar molecules.

Sugars that we ingest are broken, in the digestive system, into monosaccharides of glucose, fructose, and galactose. Almost all of the absorbed monosaccharides are first converted into glucose in the liver. This conversion is a very important task of the liver: 80% of the sugars passing into the blood are glucose. As a result, very limited amounts of fructose and galactose are present in the blood. Therefore, when blood sugar is mentioned, normally glucose is taken into consideration and the fructose and galactose levels in the blood are ignored. Glucose, which is also called grape sugar, is most abundantly found in grapes, while fructose is called fruit sugar, as it is plentiful in fruits, and galactose is named milk sugar after its dense presence in milk. The most important characteristic of fructose is that it is sweeter compared to other simple sugars.

Insulin is secreted from the pancreas in order to lower elevated blood glucose levels after digestion. Insulin functions in the transport of glucose from the blood into cells to provide necessary energy, therefore reducing blood sugar levels; furthermore, it also plays a role in the storage of excess glucose as glycogen, which is found primarily in the liver. Once glycogen storage limits are reached in the liver and muscles, glucose is then stored as fat. Fat tissue acts as sustenance during long fasting periods.

Differences between fructose, glucose, and galactose

Glucose and galactose are absorbed actively, depending on salt. They cannot be absorbed without salt while passing through the intestines. Salt is necessary for the absorption of glucose which is present in the starches of potatoes and other foods. Thus, when potato is consumed with salt, the transport of glucose into the blood is facilitated.

However, salt is not necessary in the case of fructose absorption. The intestinal absorption of fructose contained in fruit is delayed by fruit fibers, since these fibers prevent or balance the transport of fructose into the bloodstream. However, when fructose is ingested as a fruit juice, it is absorbed and joins the bloodstream much faster because of the lower fiber content.

A person feels full after a meal when neurons in the satiety center of the hypothalamus are stimulated by elevated blood glucose. Then, hunger center neurons are repressed, eliminating the feeling of hunger. Therefore, a person reduces their food intake during a meal as their blood glucose levels increase. Increased levels of amino acids and fatty acids in the blood also suppress hunger and stimulate fullness after meal. However, one important point is that fructose does not stimulate fullness in the brain. Therefore, if the blood fructose levels are elevated instead of glucose, a person cannot generate a sensation of fullness sensation. As a result, a person desires to intake more food during consumption of fructose. It is only possible for fructose to generate fullness after it has been converted into glucose by liver.

How to consume fruits?

We should prefer direct consumption of fruits instead of drinking natural or industrial fruit juices because of the high fructose content of fruits. The Prophet Muhammad, peace be upon him, consumed fruits before meals, the wisdom of which we learn only today. Fruits should be consumed at least an hour before or two hours after a meal, for sufficient time should be given for the fructose of an ingested fruit to be absorbed by the intestines and converted to glucose by the liver. Such practices will result in a reduced appetite and food intake. If fruit is consumed after a meal, a delay occurs in the conversion of fructose into glucose since the liver will be occupied by other biochemical processes, along with a full storage of nutrients; this will increase blood fructose levels and fail to reduce appetite. Fatty liver occurs as a consequence of high fat content of the blood. Arteriosclerosis and cirrhosis of the liver may be seen in people with a habit of excessive post-meal fruit consumption.

In a research carried out on laboratory animals, it was found that glucose induces fullness in the hypothalamus and suppresses food intake, whereas fructose was found to repress this effect of glucose, stimulating food intake.¹ Insulin reduces the harms of accumulating sugar in the blood by increasing lipid synthesis. Insulin also takes place in leptin secretion from adipose (fatty) tissue. Leptin is important in the prevention of obesity; therefore, insulin helps in weight loss, too. The leptin hormone causes reduced food intake by stimulating nerve cells in certain parts of the hypothalamus.² Fructose does not cause any leptin secretion because it does not stimulate an insulin release; therefore, it is not effective in generating a sense of fullness.

Ghrelin is a hormone secreted into blood by stomach cells during hunger. This hormone, which produces stomach acids, is enacted through the hypothalamus. It induces hunger, and therefore increases appetite. Insulin secretion increases along with the blood glucose levels during satiety. This eventually causes the increase of the leptin hormone, which also leads to a decrease in ghrelin secretion. As a result, fructose gets absorbed more than glucose in the intestines. Elevated fructose in the blood leads to insufficient or reduced insulin secretion. In this case, a person continues eating.

Fructose and diseases

Free circulation of lipids in the blood damages arteries and veins. For this reason, lipids are transported in “molecular vehicles” that are called as high, low, and very low density lipoproteins (HDL, LDL and VLDL). Neutral lipids (triglycerides) that are present on VLDL (very low density) vehicles are broken down with an enzyme. These lipids are then unloaded from the vehicles by cellular uptake and stored as fats. This transfer of lipids into adipose (fatty) tissue is enhanced via the insulin hormone. In the case of fructose intake, without its insulin secretion effect, lipids accumulate in the blood and liver and eventually prepare ground for liver damage and arteriosclerosis.As the result of a fructose based diet in laboratory animals, it was discovered that lipid production shifted from adipose tissue into the liver, therefore elevating the risk of high blood and liver fat levels.

There are two reasons for this shift. The first one is that fructose acts on the fat producing enzymes of the liver whereas it does not act likewise in adipose tissue.

Secondly, fructose plays an inhibitory role in the conversion of glucose into lipids in adipose tissue. Also, fructose consumption in humans has been linked to elevated blood fat levels.

Overconsumption of fructose causes increased liver fat synthesis. Phosphofructokinase is the limiting enzyme regarding the breakdown of glucose in the liver. This enzyme is regulated by citrates and ATP produced by glucose catabolism and the Krebs cycle, limiting glucose breakdown. However, there is no such limitation in fructose breakdown. Through fructose catabolism, glucose, glycogen, pyruvate, lactate, glycerol and the acyl part of acylglycerol are synthesized. This synthesis can not be limited. As a result of this excessive output and high amounts of triglycerides, VLDL is produced.³ It has been found that persons who consume two or more boxes of fructose sweetened beverages every day carry a 35% higher risk of heart disease.⁴

This isn’t the only disease associated with fructose. In some studies on laboratory animals, it has been reported that a high fructose diet is associated with hypertension.⁵ A lot of research exists suggesting that excessive fructose consumption leads to insulin resistance in both the liver and peripheral tissues, which can often cause diabetes.⁶ In a recent study, it was claimed that excessive fructose intake poses risks for renal diseases leading to glomerular hypertension, renal damage, and inflammation and damage to renal tubules and tissues.⁷

In a study conducted on 21,483 Americans who were older than two years, daily consumption of 37 gr. of fructose (8% of total calorie need) was found to be elevated to 54.7 grams (10.2% of total calorie need) gradually between the years of 1988-1994, mostly consumed by younger people. Increased use of fructose syrup was linked to obesity during the last 35 years.⁸ Furthermore, in a study carried on 1,749 male and female children and teenagers, a positive relation was found between body mass index (BMI) and excessive consumption of carbonated beverages containing high fructose concentrations.⁹ There many studies that support this report.¹⁰ Excessive fructose consumption is known to cause “metabolic syndrome” in which many diseases like obesity, arteriosclerosis, and diabetes emerge together.

Are fruit juices harmful?

Fructose syrup is being used at increasing rates in the food industry. According to the annual report of US Food and Drug Administration (FDA) for the year 2000, fructose syrups are sugar solutions containing approximately more than 50 % fructose. It is often synthesized by a conversion of corn starch into glucose by glucose isomerase.¹¹ There is also a third syrup type containing 90% fructose, however this has limited uses.

The sweetness of fructose syrup is similar to that of table sugar. It prevents the dehydration of food with its hydrophilic character. It is mostly used in aromatic foods, especially carbonated beverages and fruit juices. It prevents the proliferation of microbes with its high osmotic pressure property and makes food more resistant against them. Syrups containing 42 to 55% of fructose are used in baked goods, cereal products, dairy products, processed foods, both carbonated and regular beverages, ice creams, and frozen desserts. High fructose syrups are used in foods to decrease water activity and prevent spoilage.

Fructose syrups have a very low ash level due to application of intense purification processes during production and product color is water-white. Therefore colors of fructose used industrial foods are white as well. Fructose syrups have a lower viscosity and density compared to glucose syrups and therefore it is runny like water and not as sticky.

How to consume sugars after a meal?

Especially after a fatty meal, our body seeks sugar. The reason behind this is the requirement of sugar for the storage of lipids into fat tissue. However, this sugar should absolutely be glucose instead of fructose. Therefore, some amount of sugar can be consumed to facilitate the removal of lipids from blood after meals. This is recommended to lower blood lipid levels. However, this should not be done with fruits but with natural sugars like grape molasses. A baklava or a dessert made with industrial sugars (fructose) will not be beneficial but harmful.

In conclusion, the consumption of corn-derived fructose syrup is gradually increasing in recent years. Fructose syrup is used both in various carbonated or regular soft beverages, and in desserts. The reason for our fructose syrup preference is that it helps preserve foods longer and it leads to food addiction because it enhances appetite due to its strong sweetness. Fructose syrup is synthesized by the conversion of natural glucose in corn into fructose by isomerase enzymes. In this sense, today’s increased consumption of fructose is altering the existing sugar balance of natural food items. Overconsumption of fructose can pave the way to obesity, metabolic syndrome, arteriosclerosis, diabetes, hypertension, and arteriosclerotic heart and kidney diseases.

Arifagaoglu is a professor of medicine in Ankara, Turkey.

References

1. Wolfgang MJ, Cha SH, Sidhaye A. et al. Regulation of hypothalamic malonyl-CoA by central glucose and leptin. Proc Natl Acad Sci USA. 2007; 104: 19285-19290.
2. Guyton AC, Hall JE. “Dietary Balances; Regulation of Feeding; Obesity and Starvation; Vitemans and Minerals.” Textbook of Medical Physiology, Saunders, 2010, 843.
3. Rutledge A, Adeli K. Fructose and the metabolic syndrome: pathophysiology and molecular mechanisms. Nutr Rev. 2007; 65: 13–23.
4. Fung TT, Malik V, Rexrode KM, Manson JE, Willett WC, Hu FB. Sweetened beverage consumption and risk of coronary heart disease in women. Am J Clin Nutr. 2009;89:1037–42.
5. Barone BB, Wang NY, Bacher AC, Stewart KJ. Decreased exercise blood pressure in older adults after exercise training: contributions of increased fitness and decreased fatness. Br J Sports Med. 2009;43:52–6.
6. Blakely SR, Hallfrisch J, Reiser S, Prather ES. Long-term effects of moderate fructose feeding on glucose tolerance parameters in rats. J Nutr. 1981;111:307–314.
7. Johnson RJ, Sanchez-Lozada LG, Nakagawa T. The effect of fructose on renal biology and disease. J Am Soc Nephrol. 2010; 21(12): 2036-9.
8. Bray G. Fructose: should we worry? Int J Obes 2008;32: S127-131.
9. Forshee RA, Storey ML. Total beverage consumption and beverage choices among children and adolescents. Int J Food Sci Nutr. 2003; 54: 297–307.
10. Forshee RA, Anderson PA, Storey ML. The role of beverage consumption, physical activity, sedentary behavior, and demographics on body mass index of adolescents. Int J Food Sci Nutr. 2004; 55: 463-478.
11. Melanson KJ, Angelopoulos TJ, Nguyen V, Zukley L, Lowndes J, Rippe JM. High-fructose corn syrup, energy intake, and appetite regulation. Am J Clin Nutr. 2008; 88(6):1738S-1744S.

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.

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’.