Experiments have proved lack of sleep as a cause of death. Lab mice that are deprived of sleep for three to four consecutive days eventually die. Lack of sleep for a long period of time, especially when combined with excessive fatigue, poses a serious threat to our health.

There are intensive research efforts to understand the mysterious workings of the biological mechanisms underlying sleep. Human beings spend almost a third of their lives in sleep. Yet, the basic sleep mechanism and its functions are still not completely known. Each of many theories proposed for understanding the secrets of sleep provide different evidence, but no guaranteed results have been attained so far. Initially, sleep was considered a rest period. However, although brain activity lowers during sleep, the brain continues actively working. It can be said that the brain rests itself by working during sleep.

Scientists classify a person’s state of consciousness as one of three stages:

1. Wakefulness
2. REM sleep
3. Deep sleep

According to this classification, sleep is divided into deep sleep and REM (Rapid Eye Movement) sleep. During a night’s sleep, there is a loop of REM sleep and deep sleep. Approximately 90 minutes of deep sleep is followed by REM sleep, which lasts between 5 and 30 minutes. Approximately 75% of the total sleep span is deep sleep; 25% is REM sleep. REM sleep happens while slipping into sleep from wakefulness. Just before waking from sleep, a short-term REM is observed.

During the first hours of sleep, REM spans are shorter, and they grow longer during the last hours of sleep. If a person is extremely tired, they experience extremely short REM sleep spans within the first hour of their sleep. They may even slip into deep sleep without REM. Right after mid-sleep, REM sleep periods last longer. If a person is deprived of all or partial sleep – such as the deep sleep or REM – they will need to sleep longer at the next opportunity. If they are deprived of REM sleep or deep sleep for longer periods, they will have longer deep sleep.

REM Sleep

REM (Rapid Eye Movement) is given this name due to the intensive and fast eye movements during this sleep stage. During REM, not only the eyes but also hands, arms, legs, and fingers move. An onlooker may think the sleeper is fully awake. However, scientists are unable to fully explain the reason why it is difficult waking a person in REM, although they are active as if they are awake – this is a paradox. In fact, a person in deep sleep may be awakened easier, by either sound or touch. If it is difficult to wake a person during the REM stages in their sleep, it may also be considered as a paradox for that person to wake from REM sleep.

During REM sleep, contrary to rapid eye movements and gestures, a person’s muscles are extremely relaxed and soft, to the extent of a wrist drop. This is called REM paralysis.

The reasons, mechanisms, and even benefits of REM sleep are not known for certain. The newest theory in sleep research claims the relationship between REM sleep and acetylcholine secretion. Acetylcholine is a brain hormone that triggers movement. Yet, acetylcholine typically causes wakefulness. This, too, appears as another paradox.

Dreams seen during the REM stage are remembered more clearly. The limbic system, including the hippocampus and amygdala, is active during REM sleep, thus it is assumed that it is easier to commit dreams to memory during this stage. The hippocampus is tasked with committing (reinforcing) information.

During REM sleep, a person’s heartbeat and breathing are more frequent and irregular. This also relates to what a person sees in their dream. During this stage, the basal metabolism rate is higher or equal to that of wakefulness. Electroencephalography (EEG) readings register beta waves, which normally show during wakefulness. Alpha waves show during times of calm, when the brain rests during wakefulness, such as at times when one closes their eyes and dispels thoughts. However, when the brain is actively dealing with an issue or when a person experiences an upset, beta waves appear. Beta waves also show during REM stage. This shows that the brain is active during REM stage.

Deep sleep

This stage of sleep is also called low wave sleep or delta sleep. During this stage, movements are at minimum, and the muscle tone is harder. Heartbeat, breathing, basic metabolic rate, and blood pressure are low. Internal organs like the stomach, intestines, urinary tract, and even the liver minimize their activities and slip into an actual rest.

During this stage, dreams and even nightmares may also be seen. However, one cannot remember a majority of dreams when they wake up. It is assumed that the traffic between the cortex and the lower structures of the brain are disengaged during the deep sleep stage. People wake up from nightmares, only to usually remember the last part.

EEG readings during deep sleep stage show delta waves. The presence of delta waves hints at the disengaged traffic between the cortex and the lower nervous system components (thalamus, hypothalamus, brain stem, hippocampus). This condition also shows that the person is in deep rest, free from pain and other bodily stimuli.

Secreted at night, melatonin is a hormone that protects against cancer and slows down the aging process. Melatonin also plays a role in lowering bad cholesterol (LDL) and balancing body heat and blood pressure. Melatonin secretion starts around 10:00 p.m. and reaches its maximum around 5:00 a.m. That’s why, the most ideal sleep is after 10:00 p.m. when melatonin secretion starts. Bedside lamps are not suggested as they hinder the secretion of this night-bound hormone. People should also avoid conditions such as stress, smoking, extreme lighting, lack of adequate daylight, and working at lengthy periods, which lower melatonin level.

However, as one’s age increases, most bodily functions peak and then start to diminish. A better aging strategy would be to age in the healthiest possible manner; i.e., keeping the physical and mental functions as sharp as possible, in particular the memory, so as not to lose human dignity in old age.

Aging and Memory

As one ages, reactions start to slow, the speed of understanding and the level of concentration diminish. The precipitous decline of dopamine-containing neurons in the human brain after age 45 is a universal characteristic of the aging process. The nigrostriatal region of the brain is richest in dopamine and undergoes the most rapid aging of any brain area. Age-associated depletion of dopamine also accounts for less noticeable symptoms, like a decline in physical drives and brain functions. These reactions are mostly on a mental or psychological level. In addition to these, wrinkles appear in the skin, hairs gray, and joints become gnarly. Perhaps, most important of all, is that according to recent research carried out on the brain, by the time most people hit 40, their brainpower starts to weaken. This does not mean that people become incompetent, just a bit slower in the cognitive process. This phenomenon is called “generalized slowing” by psychologists. According to James Birren, the Associate Director of the Center on Aging at the University of California, Los Angeles, the first signs of aging appear on tests used to measure mental speed and acuity, in which people count the number of lights flashed on a screen, for instance, or trace a complicated pattern while looking at a mirror.

“But eventually the down-turn affects almost everything we do,” says Birren, “From how fast we hit the breaks when a car pulls in front of us to how quickly we learn new skills on the job or remember old what’s-her-name’s name.”

Then the question is whether the slowing process is unavoidable. According to psychologist Robert Dustman, the answer to this is yes. One of the country’s top experts on aging and the brain, Dustman directs the Neuropsychology Research Laboratory at the Veterans Affairs Medical Center in Salt Lake City. He’s just turned 70 and shows no signs of slowing down himself. “It is true that when we compare 20-year-olds with 60-year olds on almost any test that measures the speed of information processing, younger people on average score significantly better than the older ones,” he says, “But that does not have to be. There is a simple way I can ward off the scourge of slowness,” Dustman says. And the way to do this is to stay in shape.

At first it seems to go against common sense that in some way a mindless act like jogging or striding around a park is relevant to the speed of thinking. But Dustman explains the connection in a very logical way.

Every cell in the body requires a continuous supply of oxygen and nutrients to function at its peak. But surprisingly, no cells need a greater oxygen supply than the gray matter that rests between our ears. The brain, although it makes up only 2% of our body weight, uses up 25% of the glucose and oxygen supply.

Now suppose a person slips out of shape, their heart gets lazy, the arteries get clogged, the blood flow to capillaries slows down, and the oxygen and nutrient supply to the brain falls us. As a result, neurons get less than they need to function properly, the electrical signals slow down, and hence the mind slows down. A recent study shows that blood pressure (or lack of it) is highly correlated to memory; so much so that, a reduction of it causes the memory to weaken.

But getting older does not mean that one must face a full-scale slowdown, Dustman says. The problem is that by 45, when the brain is quickly falling into decline, most of us neglect to perform the activities that keep the arteries open, the heart strong, and blood flowing; namely exercise. Dustman’s own studies suggest that working out might be an antidote. In one of his studies, he ran 60 male volunteers, half in their twenties, half in their sixties, through the standard mental tests. As expected, the younger group had higher mental speeds. But when Dustman looked closely at the older group, he noticed that the ones who were exercising or had remained active had a brain speed that was comparable to that of the younger set.

The tests included actions as simple as pushing a button each time an X appeared in a long string of O’s to memorizing numbers and symbols. “On many measures,” says Dustman “the older men in good condition scored just as well as men 30 and 40 years their junior.” In real life, that is, they could find a number in a phone book or remember that sensible is a synonym for rational.

When one exercise, in other words, the sections of the brain which control movement and balance are fired up, the electrical signals zap back and forth along the nerves from the brain to the muscles and tendons. The eyes, the inner ear, and other sensory nerves all roll into action. The benefits of these can be detected clearly in the brainwaves and electrical impulses recorded by researchers.

Indeed, in Dustman’s study, the older men who were still fit had surprisingly youthful-looking brain waves. They produced more alpha waves, a pattern associated with calmness under pressure, and had steeper peaks and valleys in waves, which signifies an ability to block out distractions. Furthermore, when subjected to a sudden flash of light or a sound blast, they were faster to produce a wave called P-300, which is associated with fast reactions. “People in good shape can really focus,” says Dustman. “They can pen a letter to a friend without the sound of children playing downstairs disturbing them. They can fill out tax forms correctly after reading the directions once.” For someone who’s out of shape, the news is grim. In addition to problems that range from overweight to heart disease and diabetes, the results of a sedentary life style, it turns out that the brain will very likely start to weaken as well. Still, Dustman is optimistic. He once encouraged 42 sedentary people over 55 to exercise (walking or jogging) three times a week. After four months, the aerobic capacity of the volunteers increased 25 % and they scored better on mental speed tests. In light of this study, Dustman thinks that even easy exercise, such as brisk walking can speed up the minds of people after years of inactivity. The time required varies, however. In similar studies, it took about a year to observe an increase in the speed of the brain.

But it is not time that is important here; the goal is rather not to lose brain capacity until a very old age. It would be better if one were always to keep in shape, as it is easier to keep something that works running than to start it up again once it has slowed down. “The real benefit seems to come from making a lifelong habit of staying active,” says Dustman.

It is better to maintain a regular routine of exercises than to start up new ones. Researchers at the University of Illinois compared middle-aged lab rats who padded daily on a running mill to rats who negotiated a complicated obstacle course of rope bridges and seesaws a few times a day. Predictably, both groups got more blood flowing to the brain. But the obstacle-mastering rats had 25% more hard-wired connections between neurons. Assuming the same is true for humans, then exercises which require more brain activity are potentially more rewarding.

Aging and Sleep

The obvious dangers of not getting enough sleep include mental fuzziness, an increased chance of accidents, illness, psychological problems, and decreased productivity at work or school. But Dr. Eve Van Cauter wrote in the prestigious medical journal Lancet that less sleep can actually speed the process of aging. In her informative study, young men who were allowed to sleep only 4 hours each night showed signs of aging in less than a week. Their glucose tolerance dropped considerably, and they started to release cortisol, the stress hormone, at a greater rate than normal.

Sleep offers the body an opportunity to heal and rebuild itself. Pro-sleep nutrients might help in this cause. For example, it has been shown that nutritional supplements containing zinc, magnesium, and pyridoxine (vitamin B6) , among other benefits, help sleep efficiency. A herbal amino acid 5-hydroxytryptophan is another promising sleep aid to use in times of extreme stress. Among sleep promoting herbs from traditional Chinese medicine are ziziphus spinosa (jujube), schisandra chinensis, and bupleurum chinense (Chinese thoroughwax). These herbs seem to relax the muscles and soothe the central nervous system. Sleep is and remains to be the most precious source of energy replenishment.

Melatonin: A God-given Sleeping Pill

Melatonin is a natural molecule made by the pineal gland, which is located in the brain. Melatonin is made from an amino acid called tryptophan. Tryptophan is an essential amino acid, that is, the body cannot make it; we need to get it from the foods we eat. Tryptophan is found in wide variety of foods. As we consume tryptophan during the day, the body converts it into serotonin, an important chemical for the brain that is involved with moods. Serotonin, in turn, is converted into melatonin. This conversion occurs most efficiently at nights.

Melatonin helps to set and control the internal clock that governs the natural rhythms of the body. Each night the pineal gland produces melatonin, which helps us to fall asleep. Research about this molecule has been going on since it was discovered at Yale University by Dr. Lerner in 1958, but recently there has been a great deal more attention being paid to melatonin. About a thousand articles on melatonin are published annually. One major reason is that scientists are discovering that melatonin is not only associated with deep sleep, but also with our hormonal, immune, and nervous systems. Research is accumulating about melatonin’s role as a powerful antioxidant, its possible anti-aging benefits, and its immune-enhancing properties.

Aging and Free Radicals

A free radical is a molecule that contains an unpaired electron through reactions with the essential element oxygen. These molecules “steal” electrons from nearby molecules to complete that final electron pair for stability. Then they are no longer free radicals, but they convert the new combined molecule into a new free radical. In a living organism, this process can cause a chain reaction of severe cellular damage, unless prevented.

The theory that free radicals are agents of bodily destruction is gaining widespread acceptance, as is the value of antioxidants in preventing such an occurrence.

According to the journal Annals of Clinical and Laboratory Science, the excess of free radicals in our body, i.e. “the domino effect”, is a critical factor in many health problems. An interesting and concerning fact about free radicals is that they cause the same reactions within the cells that occur during exposure to radiation. Free radicals released in the body destroy even proteins, the essential constituents of the body that regulate hormones and enzymes and that make up nerves, muscles, skin, and hair. It is usually suggested that antioxidants are used to fight these harmful free radicals. Fruits and vegetables are plentiful in vitamins A, C, and E, the key antioxidants. Polyphenols, which are found in grapes and green tea extracts are potent antioxidants. In fact, scientists have found out that procyanidins are the most promising polyphenols. In Japan, scientists have discovered that they may be 50 times more powerful than vitamins C and E in fighting free radicals. Alpha-lipoic acid, which is soluble in both water and lipids, can neutralize free radicals throughout the body. In fact, alpha-lipoic acid is involved in so many different antioxidant functions that it has been called the “universal antioxidant.” Citrus bioflavonoids and certain fruit and vegetable pigments are also strong free radical fighters.

Deprenyl: An Anti-aging Treatment?

Deprenyl (selegiline) provides selective protection against age-related degeneration of the dopamine nervous system. It is the only inhibitor used in clinical practice. The rate at which dopamine neurons age is quite variable. Before age 45, dopamine levels stay quite stable. Starting at 45, the decrease in average dopamine content in healthy people is linear, at 13% per decade. When it reaches 30%, the symptoms of Parkinson appear.

The sensitivity of the dopaminergic nervous system to oxidizing free radicals has been well established. The protective effect of deprenyl in lessening the neurotoxic effect of the oxidants (6-hydrpxydopa and 6-hydroxydopamine) appears to correlate with increased antioxidant enzyme levels. The increase in the antioxidant level is proportional to the deprenyl intake.

There as yet has been no definitive study of the long-term use of deprenyl in healthy people as a life-extension and cognitive-enhancing drug. But there has been extensive animal research. The lifespan of deprenyl-taking rats is significantly greater than normal rats, in fact, all the control rats died before the first deprenyl-taking rat died. Early research with deprenyl in humans (early-diagnosed Parkinson patients) shows delayed development of symptoms. Deprenyl has also been established as a treatment for Alzheimer’s disease. Eventually, deprenyl has the potential of becoming a general treatment for aging in people above the age of 45.

Conclusion

Although we know for sure that there cannot be an absolute cure for aging, the results of it can be slowed down considerably. Soundness and health of mind are desirable traits for all ages, not just for the elderly. After many years, many elderly people lose much of their memory and mental capacities; this occurs just at the time when they can pass on all their wisdom and experience to the younger generations. Hopefully, with the advent of science and technology, the deficiencies in the brain due to aging can be avoided to a certain extent. The solution lies in a balanced collaboration of modern medicine and traditional natural cures that have been practiced for centuries.

References

• Life expectancy around the world http://www.mrdowling. .com/800life.html
• Peter Jaret, (1997) THINK FAST- from Health Magazine, http://www.brain.com/TFarticle.html
• Ray Sahelian, M.D., (1997) “Melatonin: Nature’s Sleeping Pill,” http://www.brain.com/melatonin.html
• Ward Dean, M.D., and Steve Wm. Fowkes. “Deprenyl: A Universal Anti-aging Strategy?,” http://www.ceri.com/ deprenyl.htm
• Spiegel, K. et al. (1999), “Impact of sleep debt on metabolic and endocrine function,” Lancet; 354 (9188):1453-9.
• Amtoft-Nielsen, J., M.D. (2002), “Researchers Find Sleepless Nights Speed up Aging,” Journal of Longevity, Vol. 8/No.5: 38-39.
• Abraham, I., M.D. (2002). “The Domino Effect – The Cause of Rapid Aging?,” Journal of Longevity, Vol 8/ No. 4: 36-38.

“The things that I fear most for my people are being overweight, sleeping too much, laziness and a lack of deep faith.” 1
Prophet Muhammad (peace and blessings be upon him)

Effective time management occurs only when we force ourselves to perform important activities within a plan so that we can reach our goals. Goal setting and planning our activities are important steps in this. But if we fail to engage in these activities and to finish them, then we end up with an unfulfilled plan on our hands. Our mind-body is the only vehicle through which we can accomplish our goals in life. Our eating habits, including the type and amount of food we eat, affect our mind-body in many ways, such as our energy and stress level and our sleep patterns. Hence, it is crucial to examine the impact of eating habits on our mind-body. It is notable that time-management literature’s vast majority pays little or no attention to this aspect of mind-body control. In this article we will consider three factors in this respect: The impact of the amount of food we eat, the timing of meals, and the nature of our food.

“Limit eating, limit sleeping, limit talking. This is the path to the spiritual life.” – Sufi proverb

The Impact of How Much We Eat and Drink

There is little mention of eating habits in time-management literature. However, our eating habits affect our management of time in many different ways. Let us first consider the times of our day that are immediately affected by our eating and drinking habits:

1. Food preparation or waiting time,

2. Eating/drinking time,

3. Digestion and mental recovery time after the meal,

4. The time spent in the lavatory, and finally

5. The extra sleep we may need after a heavy meal.

It is easy to see that the impact of each of these factors is proportional to the size of the meal. The more food we prepare or ask for, the longer the preparation/waiting time will be. More food also takes longer to eat. The next stage, which is very important, is the time needed for digestion and mental recovery after the meal. Depending on the type and amount of food we intake, the digestion time can range from one hour up to three or four hours. When the amount of food is great, our digestive system competes with our brain for the limited amount of sugar in our body. This may prevent our brain from functioning at its peak. Consequently, we may experience a lack of focus, a lack of energy, or we may feel sleepy. Most people try to compensate for such feelings by drinking caffeinated beverages, which have their own disadvantages.

The time we spend in the lavatory is also proportional to the amount of food we eat. When we eat more, our visits are more frequent and more time is spent there. Eating foods that are rich in fiber is also another cause of frequent visits to the lavatory. But a diet deficient in fiber is not healthy, so the way to cut back on time spent there is not to cut back on fiber-rich foods, but rather to cut back on the amount of food we eat.

Finally, the type and the amount of food we eat affect our sleep patterns. First, when we eat more, we need to sleep longer. It is no coincidence that people who overeat also tend to oversleep. But the impact is not limited to sleeping time alone. Stimulating foods or drinks near bedtime disturb our sleep patterns and cause us to benefit less from our sleep. This, in turn, results in our efficiency being affected the following morning.

When we consider all these factors, we begin to realize how overeating makes self-management difficult and we can understand the wisdom behind the prophetic saying “No human being has ever filled a container that is worse than his stomach. . .”2

The Impact of What We Eat and Drink

In addition to the amount of food, the type of food we eat is also important. Certain types of food may energize our brain, while certain others make it sluggish.3 In order to increase one’s energy levels, nutritionists recommend a balanced diet that is devoid of harmful substances. An important property of the food we eat is what is known as the “glycemic index.”4

The Glycemic Index of Foods

Since sugar is the substance that gives us energy, many people are under the false assumption that the more sugar we consume, the more energetic we feel. This view, however, fails to account for the compensatory balance in our body. When we consume large amounts of sugar, either in the form of pure sugar, or via foods that are rich in sugar, the amount of sugar in our blood stream increases. Our body responds to this situation by secreting insulin into the blood stream, reducing the amount of sugar. If the increase in the sugar level is very steep, than the body reacts strongly to reduce it and causes the sugar level to fall to a very low level. This is why we feel sluggish for some time after consuming sugar-rich foods.

In order to avoid the down-time of insulin compensation, nutritionists recommend that we avoid foods that are high in simple sugars and which have a high glycemic index in carbohydrates. The “glycemic index” measures how much the levels of circulating blood sugar increase within a few hours after eating a particular food. Examples of foods and drinks with lots of simple sugars include cookies, cakes and other baked goods, candy bars, sodas, and fruit juices. These foods and drinks include large amounts of simple sugars, such as glucose or fructose. Initially, they give us a quick energy boost. In the longer term, however, the body’s monitoring system increases the levels of insulin in the blood and hence we experience a quick decline shortly after this boost. The brain can only use glucose for energy. When the glucose level drops in the blood, the brain cannot perform at its peak. We may end up feeling even more drained than before we ate or drank. In order to maximize brainpower and mental focus, we need to minimize fluctuations of blood sugar by selecting foods with lower glycemic index numbers. These will break down more slowly and release glucose gradually into your bloodstream. The insulin response will also be more gradual and we will not suffer a mental down time. The following table shows the glycemic indices of certain foods:

The Interaction of Food with Hormones

Our food intake also influences the release of important hormones, such as serotonin, melatonin, and dopamine. Serotonin gives us feelings of well-being, personal security, and relaxation. A shortage of serotonin may leave us feeling very tired, needing excessive sleep, with feelings of low self-esteem, causing negative thinking, and maybe even difficulty in concentrating. However, excessive levels of serotonin are also harmful.

Melatonin is a hormone that is believed to be involved in the regulation of sleep. Melatonin secretion is significantly higher at night, although some is produced during the day. The pineal gland, where melatonin is produced, functions as a biological clock by increasing its output of melatonin at night by more than ten times. This increase in secretion begins around sunset and reaches a peak at around 2 a.m. After this peak, it falls to a low level by the time of sunrise. High levels of melatonin can induce drowsiness.

Dopamine stimulates alertness and awareness. However, excess levels can cause an increased heart rate, muscular tension, and disrupt sleep patterns, as well as resulting in shortened attention span and excessive self-confidence. Excess levels of dopamine have been associated with ADHD (Attention Deficit Hyperactivity Disorder) and risk-taking behavior.

Serotonin, melatonin, and dopamine are constantly being produced in our bodies. But we can increase or decrease their levels by changing our habits. Our eating habits, spiritual well-being, and activity all affect the hormone chemistry in our bloodstream and in our brain. These in turn affect our moods and tendencies.5 This is one reason why we can feel differently about the same task at different times of the day. Carbohydrates, for instance, can alter the level of serotonin in our brains and bring on feelings of calm and relaxation. While these effects can be desirable at night, they are certainly not what we want when we need to increase our energy level. Certain proteins can help increase levels of dopamine. Thus, we may prefer a menu rich in proteins rather than carbohydrates before a mentally demanding task. In the evening, some hours before we go to bed, we may want to avoid stimulating foods as they may interfere with our sleep. If our sleep is affected, we may wake up drowsy and drained.

The Impact of Caffeinated Drinks

Although caffeine can induce a short-term stimulation to our body and mind, it will also cause a negative rebound effect. Furthermore, in the long run the brain adapts to caffeine intake and may not be able to function at its peak when we do not supply it with the accustomed levels of caffeine. This is an unhealthy dependency. If you are already used to taking caffeine regularly to boost your energy, work on slowly eliminating it from your diet. Decaffeinated coffee and tea may help get rid of the addiction while maintaining a placebo effect. One advice for a quick lunch that will not deplete your energy, but rather increase it, is to eat pure protein. Tyrosine, one of the amino acids in protein, is well known for its ability to increase levels of alertness and energy levels. Foods such as broiled fish, sliced poultry, boiled eggs, or tuna are good sources of tyrosine.

Additional advice from nutritionists to prevent fatigue includes getting enough iron, taking advantage of herbs, and preferring natural foods over artificial ones.

Conclusion

In this article we have addressed a commonly overlooked aspect of time management: The impact of our eating habits on self-control and productivity. In addition to its negative consequences on our health, eating too much also affects how we make use of our time. Overeating is one of the primary causes for excessive sleep, fatigue, and loss of mental energy. Foods rich in simple sugars in particular are responsible for dips in performance shortly after consumption. The type of food we eat and the timing of our meals also impact our mind-body. Various hormones that affect our performance are affected by our nutrition pattern. In the prophetic saying we quoted above, Prophet Muhammad, peace and blessings be upon him, links excessive sleep, laziness, and a lack of reflection with overeating. It is remarkable that such sound medical advice came from a person who lived in the 7th century. The recommendation in this prophetic tradition is fully applicable today: Moderate eating is the key to self-control and effective time management. 

Footnotes

1. Suyuti, Jam’ul Jamawi, 832.
2. Tirmidhi, Zuhd 47; Ibn Maja, At’ima, 50.
3. Chafetz, M., Smart for Life, Penguin Books, New York: 1992.
4. Jennie Brand-Miller et al., The New Glucose Revolution –
5. Complete Guide to Glycemic Index Values, Marlowe & Company, New York: 2003.
6. Kotulak, R., Inside The Brain: Revolutionary Discoveries of How the Mind Works, Andrews McMeel Publishing, Kansas City: 1997.