Deadly Harvest: The Intimate Relationship Between Our Heath and Our Food (55 page)

Hunger Signals

Our bodies rely on a complex interplay of signals to regulate food consumption. Hormones and nerves are constantly relaying “eat” or “don’t eat” messages to our brain and back again to various parts of our digestive system.
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The details of this “chaotic” system are still not fully known and they are extraordinarily difficult, if not impossible, to analyze. However, one thing is clear: a wide variety of factors disturb the naturally adapted “eat” or “don’t eat” instructions. To date, two dozen chemical agents have been identified that stimulate appetite, and a similar number that suppress appetite. These agents, many of them hormones, have names like ghrelin, PYY, agouti, and leptin. These complex signals get misrouted when we live in ways they do not recognize. For example, compared with other people, the obese remain hungry longer and don’t feel full as quickly.
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Lack of sleep generates signals that drive up hunger pangs.
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Pharmaceutical companies are trying to find drugs to change these signals, but with little prospect of success. The chaotic nature of the interactions means that they cannot be micromanaged. Of course, we advocate dealing with root causes and not trying to second-guess nature. Appetite signals go haywire because our whole lifestyle is out of whack. Get it back into line with the Savanna Model and appetite sensations will fall into line too.

Unlike some creatures (gorillas, for example), humans were not living surrounded by their food. We do not have a well-developed “satiety reflex”—our bodies do not have strong signals telling us when to stop eating. For our ancestors, food bonanzas were rare, so we have a little voice inside us urging us to keep eating while the going is good.

Today, of course, in the affluent countries, we are surrounded by food. We can, with no effort, satisfy our desire to eat. As one wag observed: “When you hunt animals, you might succeed or you might not. But when you open the fridge door, you will succeed 100% of the time.” Instead of the discipline being exerted on us by our environment, we have to exercise self-discipline. Prosperous times do have drawbacks! A second factor is the free-for-all in the supply of food. Supermarkets are modern-day Horns of Plenty, overflowing with substances, most of which are not proper human food at all. So, we have a double challenge: to exercise self-discipline in regulating both the quantity and the nature of what we eat.

Obesity

Carrying extra fat is not just a cosmetic issue. Everything we know about our biology is that it is unhealthy to have too much body fat—it is not how nature intended. Fat in your abdomen (a potbelly) is not just sitting there as dead weight—it produces all kinds of inflammatory chemicals called cytokines. By eliminating fat, you also get rid of a very dangerous inflammation-producing organ. Inflammation is linked to many chronic illnesses, including heart disease, syndrome X, dementia, depression, cancer, osteoporosis, and autoimmune diseases.
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In chapter 1, we saw how San and Aborigine foragers had low body fat. So, why do our bodies make it so easy to put on weight? On the savanna, our bodies had to be good at storing excess food in times of abundance to see them through the times of scarcity. This storage mechanism has no upper limit: there was never a need to have one in the Pleistocene past, because scarcity was as common as abundance. Today, times are always abundant and our waistbands expand indefinitely to store the available food.

There are two major ways that food gets turned into fat. The body works to keep the level of blood sugar just right, neither too little nor too much. To do this, it uses the body’s fat cells like a bank. Sugar is not actually stored as sugar, it is stored as fat. Fat is a concentrated, space-saving form of sugar. When there is too little blood sugar, the pancreas sends out the hormone glucagon to the fat-cell bank to draw out some sugar. When there is too much blood sugar, the pancreas sends out the hormone insulin to deposit surplus sugar in the bank. In a body that is living like nature intended, these banking transactions are going on all the time. Half the transactions are credits and half are debits. In the long run, our bank balance stays modestly in credit.

In the case of obesity, far more sugar is being deposited than is being drawn out. Where does this excess blood sugar come from? By far the biggest source is “bad” carbohydrates, chiefly grains, starchy vegetables, most sugars, some drinks, and some fruits. A secondary source of blood sugar is the liver: it converts some excess protein into sugar and puts it into the bloodstream. If there is too much sugar in the blood already, it gets deposited in the fat-cell bank.

The second major way in which we get fatter is more straightforward: the fat-cell bank also accepts deposits of fat directly. However, to do this, the bank requires special instructions or the deposit will not be accepted. These instructions are given, once again, by the hormone insulin—no insulin, no deposit. This explains why Eskimos, who eat a high-fat diet, are skinny under their voluminous furs. Their diet contains no carbohydrates whatsoever to trigger insulin release. Neither Eskimos nor San Bushmen make much insulin.

So, starch is stored as fat, sugar is stored as fat, protein is stored as fat, and fat is stored as fat. With all these alternatives, it is not surprising that the way we eat today is fattening. Insulin is the common factor in these activities. Nevertheless, in natural circumstances, neither protein nor good carbohydrates cause it to be secreted in large amounts.

Finally, let us look at one more factor working to make us fat. Although protein on its own does not provoke much insulin, when we eat protein together with bad carbohydrates, the effect is multiplied.
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Insulin levels skyrocket, meaning that certain combinations of foodstuffs are exceptionally fattening. Popular foods combine bad carbohydrates, protein, and fat all the time. Examples are hamburger (bun and meat patty), hot dog (roll and sausage), French fries (potato and cooking oil), pizza (pastry and cheese), pasta (spaghetti and meat Bolognese), BLT sandwich (bacon and bread), deep-fried breaded chicken, and so on. We do not have to look far to see why Americans, and industrialized populations generally, are becoming obese.

Our diet, high in bad carbohydrates and fats, is making us fat. We put too much blood sugar and fat into storage and do not withdraw it often enough. We need to feel hungry on a regular basis, a signal that the “slimming down” hormone glucagon is operational and drawing down fat. We also need to consume fat frugally and bad carbohydrates not at all.

Seven Ways to Reduce Obesity

These steps for reducing obesity are all in accordance with the Savanna Model.

1. Consume a strictly low-glycemic diet (no starches or sugars).

2. Adopt a low-fat diet.

3. Consume protein-rich foods modestly.

4. Keep a check on alcohol intake and avoid “empty calories.” Alcohol gets in the way of glucagon working properly, so that withdrawals are harder to make from the fat-cell bank. Also, alcohol loads the body with calories that serve no useful nutritional purpose. The body uses these up first, putting calories from other sources in the fat cells. Plus, many alcoholic beverages are glycemic. Beer, with its malt sugars, is a common example. Heavy beer drinkers are much more likely to develop a “beer belly” and suffer from the diseases of a high-glycemic diet.

5. Practice the recommended amount of physical activity every day. Physical activity performs an essential role in making our body function properly. This applies just as much to weight control. The more active we are physically, the more likely we are to burn off a high intake of calories. Physical activity, at levels which conform to our naturally adapted pattern, makes wondrous improvements to blood sugar control and fat burning.
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In particular, glucagon is encouraged to withdraw fat from the fat-cell bank. Physical activity also suppresses appetite, especially in obese people.
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6. Feel hungry several times a day.

7. Get proper sleep.

Diabetes

Diabetes is the condition in which the body either does not produce enough insulin or the fat cells do not react to insulin’s signal. In other words, diabetes results when the blood sugar control mechanism goes haywire. There are three main types of diabetes: type 1, type 2, and gestational diabetes. Here, we feature type 2 diabetes, which is by far the most common (90% of all cases) and it is also a purely lifestyle disease.

Type 2 diabetes can occur for either or both of the reasons cited above: not enough insulin is made by the pancreas or the fat cells do not listen to insulin’s instructions. The latter scenario is called “insulin resistance.” In insulin resistance, the pancreas (under instructions from the brain) senses the danger and churns out yet higher amounts of insulin. The fat cells sense this flood of insulin and become yet more resistant, a vicious cycle of high glucose levels and often high insulin levels. The result is that dangerously high levels of sugar remain in the bloodstream. Over time, this leads to gangrene, limb amputations, blindness, kidney failure, and nerve death. High insulin levels increase the risk of stroke, clots, heart disease, cancer, and other serious ailments.

Insulin Medication

An outstanding event of early 20th century medicine was the discovery of insulin by the Canadians Sir Frederick Banting, Charles H. Best, and J.J.R. Macleod in 1921. Almost overnight, the fate of diabetics changed from a sentence of almost certain death to a prospect of a long and healthy life. For many decades, it was thought that insulin was a miracle cure. However, the medical establishment has come to realize that there is a dark side to insulin injections. As a powerful hormone, insulin acts on all sorts of other body functions that give rise to the higher risk of cardiovascular and many other diseases. Perhaps half the number of diabetics do not actually need insulin injections at all. In spite of that, their risks are hardly lower. They still have insulin levels out of control and similar risks of disease.

Diabetes wreaks havoc on the body. Half of all amputations of hands and feet in the United States are due to diabetes. Similarly, it is a leading cause of blindness. People who are diabetic are much more likely to be obese and have heart disease, kidney disease, high blood pressure, thromboses, strokes, and Alzheimer’s disease.
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The U.S. Centers for Disease Control predicts that the number of Americans with diabetes will double from 12 million to 24 million in the 25 years from the year 2000.
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Diabetes was unknown among hunter-gatherers like the San Bushman and the Australian Aborigines.
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It used to be a rare disease even in industrialized societies, until recent times. When it did occur, this form of diabetes used to be called “adult onset” because it happened later in life, often around middle age. This name has been dropped because it is now happening at much younger ages. In fact, it is increasing out of control among the young. A study of 10- to 19-year-old diabetics in Cincinnati, Ohio, found that doctors were diagnosing ten times the number of adolescents suffering from diabetes in 1994 compared to 1982.
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Eskimos, Aborigines, Polynesians, and American Indians develop high rates of diabetes as soon as they adopt a Western diet.
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We can take just one example, the Pima tribe of Gila, Arizona: 45% of people over 55 were already suffering diabetes in 1965. Yet, that number could soar even higher—to 80%—by 1996.
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These peoples have blood sugar control systems that cannot cope with a high-glycemic diet. This is an interesting and rare example of how the bodies of farming peoples, over the millennia, have become slightly better than hunter-gatherer bodies at handling glycemic food, but only to a point. Nobody on the planet can cope with the extreme high-glycemic diet now commonplace in Western societies.

So, why do our blood sugar control systems go haywire? Because they have caved in to the onslaught of foods that provoke an explosive blood sugar rush. The most important thing a diabetic and pre-diabetic can do is to stop presenting unreasonable demands for insulin. Avoid requiring the body to deal with foods that it was never designed to process, and insulin levels will be kept low all the time. This is how our ancestors operated, and when Aborigines and Polynesians return to their ancestral eating patterns, their diabetic symptoms improve dramatically.
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Everyone on this planet could avoid type 2 diabetes if they adopted a hunter-gatherer lifestyle.

The essential points about the hunter-gatherer lifestyle and diabetes are that their food supply was low glycemic, they had low body fat levels, and they got regular exercise. Studies demonstrate that these are vital conditions for fighting diabetes. There are further factors of secondary importance: a low omega-6 to high omega-3 ratio, a low-fat diet, the absence of smoking, suitable exposure to sunshine, and a rich intake of plant-food micronutrients are all helpful for diabetes.