Sharon awoke with hope and apprehension—hope because she was starting a new diet, apprehension because this was quite possibly her thousandth attempt to lose weight. But this time she would succeed. No more excuses, no more frustration, no more failures. This time she was going to lose weight and keep it off.
Sharon had been dieting for over twenty-five years but had never achieved permanent weight loss. She remembered weighing in at a pleasingly plump 135 pounds as she entered high school. As she stepped on the scale, the nurse had shouted out her weight for everyone to hear. She was ashamed to weigh so much and had no idea why she was heavier than the other girls. She only knew she didn’t want to be different, so she bought a calorie counter and started on a series of diets.
It was always the same. She would lose a little, then gain a little, but could never keep her weight down. As she continued to diet, she became more and more miserable.
As she grew older, she found she could not stick to a diet for more than a few weeks, and she gained more weight. The more she gained, the more she dieted, and a vicious cycle was established.
With these memories running through her mind, Sharon suddenly decided to give up dieting. After all, it had never made her thin. In all her twenty-five years of dieting she had done nothing more than feel miserable. Her excessive dieting had also endangered her health and destroyed any normal feeling she had about food. In fact, her journal revealed that being fat had not been as big a problem as dieting.
But Sharon was surprised at how difficult it was to stop dieting. She had alternately stuffed and starved herself for so long that her body did not know how to react to regular feedings. Gradually, though, after a few weeks of disciplined “nondieting,” she began to develop a normal relationship with food. She also lost some of the guilt feelings she had developed and began feeling more confident. She also began to exercise. She had tried to exercise many times before but had been unsuccessful.
After being on her “nondiet” for a few months, a most interesting thing began to happen: she began to lose weight. Her clothes got looser, and friends began to notice her weight loss. Interestingly, she lost more than fifty pounds the first year and continues to lose weight. Although she doesn’t understand what is causing this miraculous change, the change is occurring nevertheless. (See Patton, bibliography.)
Based on similar experiences of many dieters, we might well ask, “What is it about dieting that makes it so hard to lose weight?” A new theory of weight control—“setpoint theory”—seems to answer this question and others.
For many years, our prescription for obesity has simply been to decrease food intake by diet or to increase the energy output by exercise. Although this sounds reasonable enough, it has actually proved relatively unsuccessful for long-term weight control. The old “energy-in versus energy-out” theory is based on the fallacy that the body doesn’t care how much fat it stores, that weight loss is purely mathematical. Since fat contains 3500 calories per pound, says this theory, a decrease of 100 calories a day for thirty-five days should result in the loss of one pound of fat. In reality, however, people tend to maintain the same weight for long periods of time, almost regardless of food intake and physical activity. So it is very difficult to lose weight as predicted.
If weight loss were merely a reflection of total caloric intake, it would be a simple matter to lose weight by simply skipping breakfast and eating normally the rest of the day. With more drastic changes in eating patterns, even more dramatic weight changes could be expected. For instance, a change from 3000 to 1000 calories daily should reduce the weight by seventeen pounds the first month and over two hundred pounds in a year. Although predictable weight loss may occur at first (which may be as much the loss of muscle and water as of fat) the body’s weight tends to stabilize at some new lower level.
According to “setpoint” theory, the brain’s hypothalamus has a mechanism which actually regulates weight. It does this by comparing the body’s current level of fat with some kind of constant internal standard, or “setpoint.” If a person’s fat level falls below the setpoint, the body will respond by increasing appetite. If the person refuses to respond by increasing food intake, the body simply adjusts itself to protect its fat stores. It does this by adjusting its metabolic rate to maintain the body’s usual level of fat. Thus, during a diet, the body learns to burn calories more slowly. So the benefit of a low-calorie diet levels off after several weeks. Then, when the dieter resumes normal eating patterns, he or she regains weight faster than ever before because the body has a slower metabolic rate. The body can shift its metabolic rate as much as 15 to 25 percent, which can become a major factor in total fat-burning capacity over a period of time.
The fat-burning capacity of the body slows down during dieting partly because of a decrease in lean body mass, muscle. Nearly half of the weight loss in dieting comes from muscle. For instance, a twenty-pound weight loss from dieting may include seven pounds of muscle. Because most fat is burned in muscle tissue, muscle loss decreases the body’s ability to get rid of fat from fat cells.
Also, a decrease in metabolic rate and a loss of muscle causes feelings of fatigue, which may be another attempt of the body to conserve energy. In any case, many obese people are less active than their normal-weight peers.
Finally, dieting causes enzyme changes that help the body store fat. Studies have shown that adipose tissue lipoprotein lipase—a fat-storing enzyme—increases dramatically when we cut calories. The body thus becomes a more efficient fat storer than it was before.
In light of these facts, it is easy to see why Sharon’s diets were so unsuccessful. The basic problem was that, even though some initial weight loss occurred, her body’s setpoint remained unchanged. And her body did all it could to compensate for her dieting to preserve its usual fat level.
Exercise: The Key to Weight Loss
The setpoint theory of weight loss is based on the idea that to lose weight, we must lower the body’s setpoint. And the most effective way to lower the setpoint is through simple exercise. Several misconceptions about exercise have made people avoid it for years:
1. The first is that it makes people hungrier and thus works against efforts to lose weight. Research has clearly shown that moderate exercise actually may suppress, rather than stimulate, the appetite. A study by Peter Wood and his colleagues at Stanford has shown that people who run even a few miles a week eat much less than inactive people.
2. The second myth is that so few calories are burned during an exercise bout that they cannot possibly make a difference in losing weight.
Actually, exercise does burn relatively few calories. But there are still several persuasive reasons for exercise that are sometimes overlooked.
The first is that for some unknown reason, exercise seems to lower the body’s setpoint. Migrant workers, for example, always have a lower body weight during the working season than they do during the off season. And animals in the wild tend to be much leaner than those that are caged. Interestingly, those who run the most and have the highest caloric intake also lose the most body fat. And, once the setpoint is lowered, the body will work to maintain that lower fat level, just as it tried to maintain a higher fat level when the setpoint was high. For example, when experimental subjects were force-fed until their body weight was 20 to 30 percent above setpoint, their weight rapidly returned to normal after force-feeding was discontinued. This occurred because their appetites decreased and their metabolic rates increased, both dramatically.
So, once you lower your setpoint, your body’s natural mechanism will be your aid, not your enemy, in maintaining your normal weight.
Other advantages of exercise are as follows:
1. Weight loss through exercise usually results in the maintenance or increase in muscle mass, which is the place where most fat is burned. Weight lost with an exercise program may seem to be slow because initially muscle may build up as fast as fat is lost. But fat loss, not weight loss per se, is what most dieters really want. Of course, this increased ratio of muscle to fat also has long-term benefits, since muscle requires more calories than fat to maintain itself.
2. Exercise changes the enzymes of the muscle system to be more effective in burning fat. Research with long-distance runners has shown that oxidative enzymes are increased dramatically as a result of moderate aerobic exercise. These changes make it much easier to lose fat stores because of the increased ability of the muscles to burn fat.
Other advantages of exercise include a moderation of the insulin response and the release of a chemical called endorphine that makes us feel good. Obviously, then, exercise is a critical part of the weight control process.
What Kind of Exercise Is Best?
The type of exercise for weight control is crucial. Situps and pushups can tighten muscles, but only aerobic exercise can reduce body fat. Aerobic exercises such as bicycling, swimming, walking, and running are large-muscle, continuous, rhythmic type of exercises. And they cause the changes that make the body an effective machine for using fatty acids released from fat tissues. This kind of exercise is beneficial because it allows muscle to burn fat more effectively during exercise.
To be effective, aerobic exercise must be done at a moderate pace since high-intensity activities such as basketball cause the body to burn sugar and will not have a long-term effect upon the fatty acids. One way to tell if you are working at the proper intensity is to use the talk test. Exercise should be intense enough to elicit heavy breathing, but the breathing should not be so hard that you cannot carry on a conversation.
It is also critical that you get some exercise at least five days a week. Research indicates that three days a week yields a considerable aerobic effect. But four days seems to be the threshold for substantial weight loss, and six or seven days a week seems to be ideal. When a person begins an exercise program, he or she should exercise for about twenty minutes a day, until the body has toughened into the new level of work. At this point, duration should be increased by five minutes per week until forty-five minutes to an hour’s worth of work can be done. Exercising for an hour a day at a moderate pace will burn about three hundred calories of energy a day, which seems to be ideal in terms of weight control. Be sure to start at a moderate level and increase slowly, especially if the weight problem is severe or long-standing. Older people and those with special health problems should check with a doctor before beginning any exercise program. Too rapid an increase in exercise can cause injuries to an inactive or overweight body.
Cut Sugar and Fats
If restricted diets really do stimulate the body’s defenses to help maintain the fat, what kind of diet is best? Over twenty-five years ago a researcher showed that extreme obesity can be elicited in rats by raising the fat content of diets from 5 to 50 percent. Other researchers discovered the so-called “supermarket diet” (peanut butter, marshmallows, salami, chocolate milk, etc.), which consists of foods that are sweet tasting, rich in sugar, high in fat content, and low in fiber, caused obesity in rats that showed no unusual weight gains while eating rat chow. If these rats were returned to their daily routine of rat chow only, they could be returned to normal weight. This same phenomenon has been observed in humans who were transplanted into a new environment where fatty and sweet foods were readily available.
One of our major problems, then, may be that many of us eat the typical “supermarket diet” on a day-to-day basis. Almost 40 percent of the calories in the typical American diet comes in the form of fat, and each American eats over one hundred pounds of sugar per year. Changing the amounts of fat and sugar would obviously help control our weight.
Another advantage of decreasing fats and sugars is that we automatically consume more complex carbohydrates from vegetables, grains, and fruits. These kinds of foods not only have very low caloric density but also contain many vitamins and minerals so necessary for health. Changing to a diet higher in complex carbohydrates also allows a person to eat until he is satisfied. This prevents the changes associated with restricted diets that cause the body to conserve energy and store fat, but still maintains a relatively low caloric intake. A recent research study comparing the typical American diet with a diet high in complex carbohydrates showed that those eating the complex carbohydrate diet ate only half as many calories as those eating the typical American diet.
The Lord’s admonition to eat little meat, eat fruits and vegetables in the season thereof, and use wheat (grain) as the staff of life (see D&C 89) makes infinite sense in terms of new ideas relating to weight control.
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Patton, Sharon Greene. “I Quit Dieting and Lost Weight.” Family Circle, 16 Nov. 1982.