Food for Life: How the New Four Food Groups Can Save Your Life (18 page)

Some weight-loss plans, such as Dr. Atkins’s
Diet Revolution
, have promoted diets that eliminate carbohydrates and push high-protein products like meat and eggs. There are several things wrong with that. First, they are not a formula for permanent weight loss. High-protein diets will cause a loss of water from the body, and fairly quickly too. But soon the weight returns because the body tissues require a certain amount of water in order to function normally. Water can be temporarily removed, but it quickly comes back. Besides, the weight that people carry in their abdomens, hips, and thighs is not mostly water, but fat.

There are also serious dangers in high-protein diets. The first is that high-protein products are usually high in fat. The “lean” beef, chicken, fish, dairy products, and eggs that are a big part of these diets are often accompanied by generous amounts of fat and cholesterol. Second, high-protein diets are strongly linked to osteoporosis and kidney disease. As we saw in
Chapter 1
, high-protein diets cause calcium to be lost in the urine, and may be a principal reason for osteoporosis in the United States. High-protein foods also release by-products that act as diuretics, forcing the kidneys to work much harder than they should, gradually wearing out the
nephrons
, which are the kidneys’ filter units. Although we do need protein in the diet, scientists
now know that the dangers of too much protein are very real indeed.

If you have a single eight-ounce serving of haddock, you eat the recommended daily allowance of protein for the whole day in that one serving. The same is true of any similar quantity of beef, pork, poultry, or other fish. Including such foods in your daily diet makes it very difficult to limit your protein intake to a safe level. The same problem applies to egg whites. Of the calories in an egg white, fully 85 percent are from protein. A person who has two eggs for breakfast gets 12 grams of protein with virtually no complex carbohydrate, no fiber, and no vitamin C.

Grains, beans, and vegetables contain more than enough protein, but not an excess. There is no need to combine these foods in any particular way. Any normal variety of plant foods provides the protein your body needs. Meats, chicken, fish, and high-protein drinks drive the protein content beyond what the body can handle safely.

If we discover that we are heavier than we want to be, there is a natural inclination to eat less food. We may skip lunch, eat only a tiny amount of our dinner, and hope that, if our body is not getting much in the way of food, it will burn off some of its fat. Many diets are based on the theory that overweight people got that way from overeating and the answer must be to cut back.

Nature will have none of this. Nature fights diets. The human body took shape millions of years ago, and at that time there were no diets. The only low-calorie event in people’s lives was starvation. And those who could cope with a temporary lack of food were the ones who survived. So our bodies have built-in mechanisms to survive in the face of low food intake.

When you start a low-calorie diet, you know that you are trying to lose weight. But as far as your body is concerned, you must be starving. And biological mechanisms automatically kick into action to counter starvation. First, your metabolism slows down. Next, your body gets set to binge on the first available food. But let’s take a closer look at what happens.

Our bodies are always active. Even when we are asleep, we are breathing, our blood is pumping through our veins, our body temperature is carefully monitored and regulated, and our minds are conjuring up
dreams of our worries and desires. The body is expending a fair amount of effort every minute keeping its machinery in running order. When we awaken, the activities of the day demand much more of the body’s energy.

To power all these activities, our bodies can use the energy of foods or the energy stored as fat. We use up these fuels the way an automobile burns gas. A car that is roaring up hills and zigzagging through traffic uses up a fair amount of gas, while a car that is idling or slowly moving along will leave a lot in the tank.

The speed at which our bodies consume energy is called the
metabolic rate
. In periods of food shortage the body slows down the metabolism to conserve energy. Just as a motorist who is running out of fuel tries to go easy on the accelerator and drive very smoothly to conserve gas, the body does the same sort of thing when food is in short supply. It turns down the metabolic flame to save as much of the fat on your body as possible until the starvation period is over, because fat is the body’s fuel reserve. Body functions are turned down a bit, body temperature may fall, constipation will occur, and menstrual periods may stop.

If you go on a low-calorie diet, your body thinks you are starving. You can explain to your body that you are not trying to save your fat, you are trying to get rid of it. But your body is not listening. The more your food intake drops, the harder your body tries to keep from losing fat.
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The effect is significant. On a 500-calorie diet, your metabolic rate can drop 15 to 20 percent below normal.
⁵

This is very frustrating to dieters. They often find that, as the diet goes along, it becomes harder and harder to lose weight. Even worse, when the diet is over and they go back to eating normal portions, their slowed metabolism continues, so fat is rapidly accumulated again, often up to and beyond their starting weight. It takes weeks for the metabolism to speed up again. Researchers at the University of Pennsylvania found that five weeks after a group of individuals stopped a very low calorie diet, their metabolic rates had still not fully recovered.
⁵
This leads to the familiar yo-yo phenomenon, in which dieters lose some weight, then rebound to a higher weight than they started with.

The secret to keeping your metabolism from slowing is to make sure that your diet contains at least ten calories per pound of your ideal body weight. If you are aiming for a weight of 120 pounds, your daily menu should contain at least 1,200 calories. If you have less food than this, you run the risk of slowing your metabolism.

The body’s second defense against starvation is the binge. This is an automatic mechanism. Your body cannot differentiate a diet from a journey through the desert, where whatever food you come across could be the only food you will have for a long time. So it gets ready to take maximal advantage of any food source it finds. This is called the “restrained-eater” phenomenon.

Does this sound familiar? You have been dieting for several days. You had a tiny breakfast, skipped lunch, and then in the evening someone brings home a carton of ice cream. A little bit won’t hurt, you decide as you take a taste, and before you know it you are scraping the bottom of the carton and digging around the cracks for every last bit. You then feel remorse for your “lack of willpower.” The truth is that this has nothing whatsoever to do with willpower. Your body disconnected your brain, in effect, in order to accomplish a predictable biological phenomenon. Your body was operating on the assumption that the food in front of you might be the only food you would have for a while, so it demanded a binge.

Diets are not the only thing that leads to binging. Skipping meals also results in overeating later in the day. So if you have been a dieter whose self-esteem has been shot by binges, be kind to yourself. It is not a question of weak will or gluttony. The diet simply ran into something more powerful
than itself—a built-in binge mechanism—and anyone would have had the same reaction.

But frequent binges can turn into bulimia: binge eating often followed by purging. Bulimia almost always begins with a diet and ends with a sense of shame and moral failing. Guilt leads to hiding food and secretiveness about eating habits, while the individual feels out of control and helpless. If this has happened to you, remember that binging is not a moral failing. It is a natural biological consequence of dieting. Many cases of bulimia would probably never occur if dieting were replaced with better food choices, which we will describe shortly.

Unfortunately, children in America are raised on a menu of fatty foods that makes many of them gain weight, especially in combination with an increasingly sedentary life-style. The predictable result is that many people become overweight. They mistakenly believe that the problem is the
quantity
of food they are eating, rather than the
type
of food, so many begin restrictive diets. The natural result is lowered metabolic rates, cravings, and binges.

It is long past the time to set aside a popular misconception. This misconception is the role of the calorie. The myth is that heavy people got that way just by eating too many calories. Calories are a consideration, but overall they are not the cause of obesity in America. If you have been counting calories, it is time to throw the calorie chart away.

For the vast majority of people, overweight is caused not by
how much
they eat but by
what
they eat. Americans actually take in fewer calories each day than they did at the beginning of the century. If calories alone were the cause of overweight, we should all be thin. But we are not. Collectively, we are heavier than ever. Partly it is because we are more sedentary now. And the
content
of the American plate has changed dramatically. My grandparents ate beans, vegetables, fruits, bread, and rice; meat and butter were not everyday fare. But all that has changed. Today we eat meats—and all the fat they hold—two to three times a day, with cheese and fried foods adding even more fat. Indeed, there is 30 percent more fat in our diet today than in 1910.

You might say, so what? What difference does it make if we eat more greasy foods? It makes all the difference in the world. When researchers compare overweight people and thin people, they find that they eat roughly the same number of calories. What makes overweight people different is the amount of fat they eat.
⁶
Thin people generally eat less fat and more carbohydrate. As we will see shortly, fat in foods adds very easily to the fat on your body, while the carbohydrate in vegetables, grains, beans, and fruits helps your body burn up calories.

To follow are some simple but profound ideas for changing your diet that allow you to eat essentially unrestricted portions and maintain permanent control of your weight. The key is to base your menu on grains, vegetables, beans, and fruits. These foods are high in complex carbohydrate and fiber and very low in fat. But let’s take a minute to see why these foods are so powerful for weight control.

Foods from plants are nature’s only supply of complex carbohydrates.
Complex carbohydrate
is a chemists’ term for molecules made up of many sugars linked together. When you eat the starchy white insides of a potato, or for that matter just about any other vegetable, the carbohydrate is gradually broken apart into simple sugars, which are absorbed and used by the body.

Not so long ago people believed that carbohydrates were fattening. Dieters would avoid starchy foods. They never went near bread, potatoes, or pasta. It turns out that carbohydrates were, in fact, innocent bystanders. People would take a piece of toast, which has only 64 calories, and slap on a pat of butter, which boosts the calorie content by more than 50 percent. Or they might take a baked potato, which has only 95 calories, and top it with a pat or two of butter, a spoonful of sour cream, some grated cheese, and some bacon bits. As they gained weight, they blamed the bread and potatoes. But the real culprits were the greasy toppings. In fact, carbohydrates are very important for permanent weight control.

For the calorie conscious, carbohydrates are naturally very low in calories. A gram (about ⅓ ounce) of carbohydrate has only 4 calories. Compare that to a gram of fat, which has 9 calories—more than twice the calorie content of carbohydrate. It is only when carbohydrate-rich foods are covered with fatty toppings that lots of calories are added.

Carbohydrate-rich meals are not just low in calories. They actually change your body. They readjust your hormones, which in turn boost your metabolism and speed the burning of calories. One of these hormones is thyroid hormone. Below your Adam’s apple, your thyroid gland manufactures a hormone called
T4
, so named because it has four iodine atoms attached. This hormone has two possible fates: It can be converted into the active form of thyroid hormone called
T3
, which boosts your metabolism and keeps your body burning calories, or it can be converted to an inactive hormone, called
reverse T3
. When your diet is rich in carbohydrates, more of the T4 is converted to T3, and your metabolism gets a good boost. If your diet is low in carbohydrate, more of the T4 is turned into reverse T3, resulting in a slowed metabolism. The same thing occurs during periods of very low calorie dieting or starvation. Less of the T4 is converted to T3 and more to the useless reverse T3. This is presumably the body’s way of guarding its reserves of fat; when not much food is coming in, the body conserves fat and turns down production of the fat-burning hormone, T3. But a diet generous in carbohydrates keeps T3 levels high and keeps the fat fires burning.
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