There are two primary reasons why obesity is a major health problem in the United States. First, it increases a person’s risk for some of the most serious diseases that afflict our society. Second, it can impair our quality of life, even without any of these diseases. Obesity is risky because of what it does and because of what it leads to. In this chapter, we will discuss prevention and treatment of this disorder. Proper diet is a cornerstone of both. But before we discuss either prevention or treatment, it is very important that we understand what obesity is, how it develops, and why it is dangerous.
Obesity is not simply being overweight. An obese individual is a person whose body contains too much fat. The 280-pound linebacker for the Dallas Cowboys is not obese; nor is the gold medalist in the women’s Olympic shot-put competition; nor is the well-conditioned heavyweight boxer. These people may be overweight, but their excess weight is in the form of muscle tissue. For most of us, overweight means too much fat.
The simplest way of judging whether you have an excess of fat in your body is to examine your weight relative to height. Are you too heavy for your height and body build? Table 11, adapted from Metropolitan Life Insurance data, shows the ideal body weights for both men and women of a given height and body build. This table was constructed from actuarial data. Although we cannot say that these are necessarily the best numbers for you, they serve as a good general guide.
As any population begins to exceed ideal weight, the life span of that population starts to decrease. If you weigh 10 percent above your ideal weight, you are bordering on obesity. A figure of 20 percent above your ideal weight means definite obesity. If your weight is between those ranges, you are in the caution zone. If you are obese, you are at risk of shortening your life span.
If you are not sure that your overweight means too much fat, there are sophisticated ways of determining the amount of fat in your body. One of these methods employs skin calipers to measure the thickness of the fat layer on your arms or back. The skin-caliper is useful in differentiating the very muscular individual from the person who is equally overweight because of too much fat tissue. This method is also valuable in following the course of weight gain in infants and children. It can pick up small deviations that may be early warning signals for impending obesity. However, for most of us, special techniques like these are not necessary. Ten to twenty percent above ideal weight means danger. More than twenty percent means obesity—too much fat in our body.
Table 11. The Metropolitan Height & Weight Table
Height Small Medium Large
ft. in. Frame Frame Frame
4 10 102-111 109-121 118-131
4 11 103-113 111-123 120-134
5 0 104-115 113-126 122-137
5 1 106-118 115-129 125-140
5 2 108-121 118-132 128-143
5 3 111-124 121-135 131-147
5 4 114-127 124-138 134-151
5 5 117-130 127-141 137-155
5 6 120-133 130-144 140-159
5 7 123-136 133-147 143-163
5 8 126-139 136-150 146-167
5 9 129-142 139-153 149-170
5 10 132-145 142-156 152-173
5 11 135-148 145-159 155-176
6 0 138-151 148-162 158-179
Height Small Medium Large
ft. in. Frame Frame Frame
5 2 128-134 131-141 138-150
5 3 130-136 133-143 140-153
5 4 132-138 135-145 142-156
5 5 134-140 137-148 144-160
5 6 136-142 139-151 146-164
5 7 138-145 142-154 149-168
5 8 140-148 145-157 152-172
5 9 142-151 148-160 155-176
5 10 144-151 151-163 158-180
5 11 146-157 154-166 161-184
6 0 149-160 157-170 164-188
6 1 152-164 160-174 168-192
6 2 155-158 164-174 172-197
6 3 158-172 167-182 176-202
6 4 162-176 171-187 181-207
Although obesity simply means too much body fat, the nature of that obesity may vary, depending on how that fat is stored in our bodies. Like any other tissue, fat or adipose tissue is composed of hundreds of millions of cells (adipocytes or fat cells), each of which contains a droplet of fat within its walls. When the body burns more fat, the droplets shrink. When the body needs to store more fat, the droplets swell. In some obese persons, fat cells are swollen to three or four times their normal size. Thus, one way to become obese is to expand our fat cells. A second way in which the body can deposit excess fat is by creating more fat cells. If you are obese, your body contains too much fat. This fat may be packaged in different ways. You may have a normal number of fat cells, each swollen with an excess of fat and, therefore, too large. You may have too many fat cells, each containing a normal amount of fat and hence of normal size. Or you may be obese as a result of an excess number of fat cells, each of which is too large.
It is important that we understand the differences between these types of obesity. The nature of the obesity may determine the success or failure of treatment. Weight reduction is accomplished by shrinkage in fat-cell size and not by a reduction of fat-cell number. If you have excess fat cells, you will always have too many fat cells, no matter how much dieting you do. For example, let us suppose a person has twice as many fat cells as normal and that each cell contains just the right amount of fat. Such a person would be quite obese. His or her body would contain twice as much total fat as it should. For that individual to achieve normal weight, half of the fat from each cell would have to be burned. Thus, the fat cells would shrink to half their normal size. The fat tissue of this person, who has painfully dieted down to ideal weight, would appear more abnormal than when he or she was obese. There would be too many fat cells, which are now too small as well. The body somehow senses this double abnormality and struggles to rectify it by filling “depleted” fat cells with more fat. For this reason it is very difficult for a person whose obesity is due to too many fat cells (hyperplastic obesity) to lose weight. It is even more difficult for that individual to maintain the weight loss.
By contrast, let us examine the obese individual who has a normal number of fat cells, each containing twice as much fat as it should. The fat cells shrink as this person loses weight. When ideal weight is attained, the fat cells return to their normal size. This person’s weight is normal. He or she has fat tissue composed of a normal number of normal-sized fat cells. This condition, with normal fat cells, is therefore much easier to maintain. Since the most dangerous form of obesity is characterized by an increased number of fat cells, it is fair to ask how this happens.
Most tissues of the body increase their cell number only during the early phases of their growing period (from fetal life through early childhood). Adipose tissue also adds new cells early in life. The period during which this can occur extends from before birth to the end of adolescence. Thus, the person who first became obese as an adult will simply have enlarged the size of already existing fat cells. By contrast, obesity beginning any time during childhood incorporates an increased number of those cells. This is why childhood obesity is particularly serious. It almost invariably leads to adult obesity, usually the kind that is very intractable. The causes of childhood obesity are very similar to those of adult obesity. The consequences, however, may be quite different.
Fat is deposited when the energy from the food we eat is greater than the energy expended to keep our body functioning at rest and during exercise. It seems simple enough. Energy in equals energy out plus fat. The person who is fat consumes more energy than he expends. For years, however, people have interpreted this to mean that the obese person consumes more food or exercises less than the lean person. This may be true for a few obese people; but, for the vast majority, it is not. They simply do not eat more than lean people; and while they may exercise less, many will have exercise patterns similar to those of their lean counter parts but still gain weight or remain obese.
Some basic experiments dramatized this paradox.
Some obese volunteers spent several weeks in specially constructed rooms in which the amount of energy expended by all forms of exercise could be measured. One obese female patient gained weight. Yet, she was given the same number of calories necessary for a lean woman to maintain her weight; and she burned the same number of calories by physical exercise. To reduce, she needed to lower her caloric intake to levels below that necessary for the leaner woman to lose weight. Even more impressive was that a person weighing 250 pounds, but whose ideal weight was 150 pounds, first reduced to that weight and then stayed in the type of room described above. In an adjoining room was a woman who was always at her ideal weight of 150 pounds. Both women received the same number of calories daily. Both did the same daily exercises; and measurements showed that both expended the same amount of energy doing the exercises. Yet, over the course of several weeks, the formerly obese woman gained significant weight; whereas, the woman who had been lean all her life remained the same.
Why obese and lean people respond differently is now understood. Most of the energy in our food is expended to keep our complex body machinery running. Energy is used in every heartbeat, in every breath we take, in the contraction of our stomachs, in the functioning of our kidneys, etc. It is also used to maintain our body temperature at 98.6°F. The amount of energy necessary for all these functions varies from person to person. Some people are much more efficient than others. When food is scarce, the people who use energy most efficiently have an advantage. Their bodies run smoothly on fewer calories. They will survive longer periods of famine than their neighbors will. Thus, as the human race evolved in a world constantly plagued by food shortages, the more efficient calorie converters were favored to survive by the process of natural selection.
Obesity is not a punishment for gluttony but a “reward” for efficiency. The abundance of food in modern Western societies is a disadvantage for the efficient calorie converter. At any given level of intake, such an individual requires fewer calories to run his metabolic processes, and he rapidly develops a calorie surplus that his body converts to fat. The obese individual handles calories more efficiently than the lean one who can eat seemingly unlimited calories and not gain weight. With our abundance, inefficiency is rewarded
One observation that has provoked a great deal of speculation is the existence of a thermogenic organ known as brown fat. This organ converts food energy into heat energy. It is very pronounced in hibernating animals, which explains why they can stay warm without any physical activity and without shivering in the cold. In rodents, brown fat can increase energy expenditure by as much as 200 percent. It is not as pronounced in humans. Yet, our two ounces of brown fat can increase our energy expenditure by nearly 25 percent. This explains why babies can stay warm without putting on clothes, lighting fires, or shivering. We lose most of our brown fat at around thirty years of age. Is it a coincidence that this is when we start putting on our “middle age spread”? Do some people retain their two ounces of brown fat longer than others? We don’t have the answers.
There are three ways to lose weight: Reduce the number of calories to such an extent that even an efficient metabolism is starved; change the metabolic rate to become less efficient; or increase the amount of physical exercise to burn off the excess fat. In practice, only the first and last alternatives are available. There are no good methods for making our bodies waste calories. Certain drugs do this either temporarily or permanently, but they have serious side effects. Various diets have been advocated to waste calories, or change the metabolic rate; but some of these diets may be dangerous. If you try one of the unbalanced regimes, consider yourself a “human guinea pig.” There are some studies on low carbohydrate diets, for example, that show promise for quick weight loss; but the long term consequences are not known. Until we devise a safe method for altering an obese person’s metabolism, the only way to lose weight is to consume fewer calories, exercise more, or (preferably) both. Neither of these options is easy for obese people. Some will have to consume fewer than 1,500 calories per day to keep from gaining weight, even if they exercise quite vigorously every day. It is not surprising that most reducing diets fail to achieve and maintain ideal weight.
Like most nutritionally related diseases, obesity has several causes. There is a genetic component, which we are just beginning to understand. Other components are related to lifestyle. The person with a genetic predisposition to obesity becomes obese because of his or her way of life.
Obesity runs in families. If one parent is obese the chances of a child’s being obese are about 30 percent. The chances increase to over 60 percent if both parents are obese. These statistics alone, however, do not prove that obesity is in any way a genetic disease. Obese parents may simply tend to overfeed their children. In fact, a study published several years ago in an attempt to “disprove” the genetic theory of obesity suggested a prediction that not only would obese parents have obese children, but that the family dog, too, would be obese.
Accurate studies have revealed more directly the importance of genetics in obesity. For example, identical twins raised in different foster homes tended to conform to the same body type regardless of whether the foster parents were obese. Thus, if one twin was fat, the other was fat. If one was lean, the other also was lean. The genetic similarity between identical twins was so close that it overrode all the contributions of the children’s different environments. By contrast, as the genetic similarity became less close (fraternal twins or siblings), the environmental effect was more noticeable. The children began to assume the body type of the rest of the family in which they were raised. From these observations, we can deduce that two factors contribute to the high incidence of obesity in children of obese parents. One is the child’s genetic background. The other is the environment in which the child grows up.
Animal studies suggest the nature of one type of genetic abnormality. Several strains of laboratory rats and mice are genetically obese. In some of these strains, the type of obesity resembles that in humans. The animals formed too many fat cells early in life. Later, the fat cells swelled. Careful evaluations showed that beginning at about two weeks of age, the rate of replication of fat cells is faster than normal. Thus, genetically obese animals lay down more fat cells because the fat cells replicate themselves too quickly. However, this is not the only reason these animals wind up with an enormous excess of fat cells. In normal rats, fat cells stop dividing by one month of age. In genetically obese animals, fat-cell division continues until they are at least six months of age. The genetic abnormality lies in both the speed at which the fat cells divide and the length of time they continue to divide.
If we can draw an analogy to humans, it means that division of fat cells continues beyond adolescence in genetically susceptible persons. This has enormous implications for both prevention and treatment. Until recently, we believed that if we could prevent obesity in childhood we would be able to eliminate the kind of obesity in which fat-cell numbers increased. We now know that this may not be true in all genetically prone people. In such people, preventing the creation of too many fat cells may require special precautions through middle adult life. Another aspect of this phenomenon involves the differences between men and women. It appears that women may increase their number of fat cells during pregnancy. With multiple pregnancies, this can result in cumulative growth in fat cell numbers.
While cellular abnormality may be the genetic weakness in some obese people, the genetic factor is probably quite different in most of us. As we have seen, some people are more efficient in the way they handle calories. They inherited this increased efficiency from their parents; and it puts them at increased risk for obesity. The more efficient we are, the higher our risk.
The number of calories that constitutes an excess varies from person to person. Thus, our risk for obesity depends on our metabolic efficiency and how many calories we consume. Our efficiency, as far as we know, is genetically determined. By contrast, the calories we consume are largely a function of our lifestyle, and therefore under our own control.
If we agree that the amount of fat we gain depends on the number of calories we consume minus the number of calories we expend on metabolic processes and on physical exercise, then the way we can reduce that fat is to reduce the calories we ingest, or increase the amount of our exercise (or both). This means that we must alter our lifestyle—sometimes radically!
The number of calories a person consumes depends on the amount and the kinds of food he or she eats. However, the quantity and quality of our diets are influenced by a great number of additional factors—appetite, culture, religion, ethnicity, social customs, and many others. Therefore, while it is easy to agree that calorie control is the cornerstone of any program to prevent or treat obesity, limiting the number of calories we consume may be very difficult.
Let us begin with appetite. Some people appear to be hungry all the time. Others consume tiny amounts of food and have to force themselves to do that. Appetite is controlled by a center in our brains called the hypothalamus. That center is divided into two areas, one that stimulates appetite and another that inhibits it. In addition, when one of these areas is turned on, it turns the other off. Thus, a control mechanism within our brains can make us eat more or less. In animals, destroying the appetite-stimulating area of the hypothalamus will cause the animal to starve itself to death in the presence of an abundance of food. By contrast, destroying the appetite-inhibiting area causes the animal to eat enormous amounts of food and rapidly become obese. There are people with tumors of the hypothalamus that have affected their appetite regulation so that they have become morbidly obese. Their obesity is cured when the tumors are removed.
A network of nerve connections from other parts of the brain influences both the appetite-stimulating and appetite-inhibiting areas of the hypothalamus. These nerves can be activated by “cues” from outside the body (external cues) or from inside the body (internal cues). In other words, our appetite can be stimulated or inhibited by what we see, what we smell, or what we taste (all external cues). It can also be aroused by contractions in our gastrointestinal tract or even by the thought of a delicious meal (both internal cues).
There is a natural substance (ghrelin) that carries messages between the brain and the digestive system. Secreted by specialized cells in the stomach and the upper part of the small intestine, it acts on the brain. Ghrelin levels in the blood spike before meals and drop afterward. People given ghrelin injections felt voraciously hungry, and, when turned loose at a buffet, ate 30 percent more than they normally would.
Dieters who lose weight and then try to keep it off make more ghrelin than they did before dieting, as if their bodies are fighting to regain the lost fat. By contrast, very obese people who have an operation called gastric bypass to lose weight wind up with relatively little ghrelin, which may help explain why their appetites decrease markedly after the surgery.
Leptin, an appetite suppressant made by fat cells and once thought to have great promise as a treatment for obesity, has turned out to be a disappointment because most overweight people are resistant to its effects.
Because it occurs outside the brain, ghrelin may be a relatively easy target for scientists looking for ways to manipulate weight.
Indeed, you may think that we already have a “safe” medication for obesity; and it is true that some of the worst hazards of “diet pills” have been reduced or eliminated with the introduction of some drugs now available by prescription. These prescription drugs act much like amphetamines but are not nearly so addictive; and they do not seem to have as much danger of the severe mind altering effects of amphetamines. But they introduced a new hazard (pulmonary hypertension), which does not threaten everybody who takes them but is often fatal to those who are afflicted with this drug-induced disorder. Also, the drugs do not “cure” obesity. People who take them usually gain the weight back when they discontinue the drugs. And, even if drugs do succeed in eliminating the need for “reducing” diets, our need for nutritional balance in what we eat will still be there.
If we could control our hypothalamus, we would have a powerful weapon for combating obesity. We are beginning to understand how this complex area of the brain works. However, we have not reached the stage where we can safely alter hypothalamic function in obese people. We do known that the function of the hypothalamus, and, hence, control of appetite, differs between obese and lean people. A dramatic example comes from a series of studies in which obese and lean subjects received all their food in liquid form. The supply of this liquid was kept in a refrigerator that had a drinking tube protruding through one of its walls. Whenever the person was hungry, he or she drank as much as desired. The amount consumed was registered electronically in another room.
After a few days, each person reached a constant caloric intake. Not surprisingly, the obese subjects did not consume very many more calories than the lean subjects did. After a few days at this intake level, the calorie content of the liquid diet was cut in half while its taste and consistency remained the same. The subjects were unaware of the change. Lean subjects almost immediately began to consume almost twice as much of the liquid diet. By contrast, obese participants continued to consume roughly the same quantity as before. In a lean subject the number of calories being offered was somehow communicated to the hypothalamus, which by regulating the appetite centers was able to control the amount of food intake. For an obese individual, there seemed to be another kind of control. Either this type of feeding regimen did not influence the hypothalamus or the volume of liquid was governing the food intake.
Another series of studies was devised to differentiate between these two possibilities. Lean and obese subjects were given access to unlimited quantities of food in a smorgasbord fashion. Again, over a few days, both lean and obese subjects reached a constant intake. In this experiment, however, the obese individuals did tend to take in more food than the lean ones—but not enough to account for the obesity. Then a sugar substitute was incorporated into the foods to reduce their caloric content. Again, the subjects were unaware of the change. The lean subjects, as before, increased their food intake enough to reach the caloric level they had previously been consuming. The obese subjects changed their eating patterns very little. In addition, since a great variety of foods was available and all the subjects had free choice, markedly different volumes were consumed by subjects in both groups.
There was no relationship between the amount of food consumed and the change in appetite that occurred when the caloric content changed. Again, the lean individuals were responding to an internal cue sent to the brain in response to the number of calories in the diet. By contrast, the obese subjects were not responding either to the caloric content of the food or to the volume consumed. Experiments such as these have led us to believe that the food intake of obese individuals is regulated more by external cues than by internal cues. Or, simply, lean individuals eat when they are hungry. Obese individuals are more likely to eat out of habit—when they are bored, when they are nervous, when they watch television, and so forth. The eating pattern of an obese individual, then, is much more sensitive to certain lifestyle components not usually associated with diet. It is not yet clear which came first, the obesity or the altered response of the hypothalamus. Do obese people respond more to external cues because they are obese? Or do people who respond more to external cues tend to become obese?
One external cue that we have assumed for years to be much more sensitive in obese people is their preference for sweet-tasting foods. Obese individuals were said to have a “sweet tooth,” and this sweet tooth was thought to be largely responsible for their obesity. Controlled studies show that neither of these statements is valid. Obese adults given a series of liquid solutions of increasing sweetness preferred the less sweet solutions. Their lean counterparts did not. This preference persisted even after weight reduction. In obese adolescents the results were somewhat different. They, also, preferred less sweet solutions, but after weight reduction their preference was the same as in the lean subjects. Thus, obese individuals, if anything, have less of a sweet tooth than lean people. Even after losing weight, they show no increased preference for sweet foods.
Other data suggest that obese subjects do prefer fat in their diets. This preference may persist after weight reduction. Since fat contains more than twice as many calories per gram as either carbohydrates or protein, this suggestion could be very important. Reducing diets low in fat may be particularly difficult for obese people to maintain. Since low fat is a cornerstone of most sensible reducing diets, and since Americans consume a high-fat diet, which also increases their risk for certain other serious diseases, the challenge may be in determining how to reduce the fat in an obese person’s diet without destroying his or her incentive to continue that diet.
One approach that has had perhaps more success than any other in achieving lasting weight reduction has been behavior modification. This method uses the premise that by altering our behavior we can minimize our exposure to the external cues that stimulate our appetite center. As important as appetite is, it alone does not control the number of calories we consume. People do not eat simply because they are hungry. They also eat and drink for social reasons. Almost no social occasion is observed without some kind of food or beverage. These are often very high in calories.
Even more important is the kind of foods consumed at regular meals. This will vary with a person’s ethnic background, family customs, and many other factors. Italians eat quite differently from the Japanese. And, even after several generations in the United States, many ethnic differences remain. Religious practices, such as keeping kosher or eating no meat, carry with them certain obvious nutritional implications. Often the kind of foods eaten will determine the number of calories consumed. Seventh Day Adventists are almost always on a low-calorie diet. Eastern European Jews often eat more fat and hence have a higher-calorie diet than do Orientals. Therefore, any weight-reduction program must take into account that person’s eating habits. There is no sense in trying a diet that consists of foods that you will not be able to incorporate into your way of life. Even if you can stay on such a diet long enough to lose some weight, you will gain it back as soon as you resume your previous eating habits.
Physical exercise will affect our weight in two ways. First, exercise burns calories directly. Second, exercise, in some manner, causes the body to consume more energy than can be accounted for by the amount of physical work. Whether certain exercises cause the body to become less “efficient” in handling calories is still unclear. We do believe that this is an important mechanism by which exercise aids in weight reduction.
A pound of body fat contains about 3,500 calories. To lose one pound of fat, you must burn 3,500 calories more than you eat. If you burn 500 calories more a day than you eat, you will lose one pound of fat a week. Thus, if you normally burn 1,700 calories a day and you stick to a 1,200-calorie per day diet, you can theoretically expect to lose a pound of fat each week. When you begin a weight-reduction diet, you may at first lose weight somewhat faster, primarily because of loss of water.
Alternatively, you may continue to eat the same number of calories (1,700 calories in the example given above) and burn 500 calories more a day by increasing your exercise. Or, better yet, you may lose weight by combining both exercise and reduced caloric intake. To determine how you can lose one pound per week, first decide what is you ideal weight (from Table 11, for example); estimate your activity level; and then subtract 500 calories from the corresponding calorie level in Table 12.
Table 12: Ideal Caloric Level Based on
Desirable Weight, Activity Level, and Sex
Desirable Very Sedentary Mod. Super
Weight Sex Sedentary Active Active Active
90 M 1170 1260 1350 1440 1530
F 1053 1134 1215 1296 1377
95 M 1235 1330 1425 1520 1615
F 1111 1197 1282 1368 1453
100 M 1300 1400 1500 1600 1700
F 1170 1260 1350 1440 1530
105 M 1365 1470 1575 1680 1785
F 1228 1323 1417 1512 1606
110 M 1430 1540 1650 1760 1870
F 1287 1386 1485 1584 1683
115 M 1495 1610 1725 1840 1955
F 1345 1449 1552 1656 1759
120 M 1560 1680 1800 1920 2040
F 1404 1512 1620 1728 1836
125 M 1625 1750 1875 2000 2125
F 1462 1575 1687 1800 1912
130 M 1690 1820 1950 2080 2210
F 1521 1638 1755 1872 1989
135 M 1755 1890 2025 2160 2295
F 1579 1701 1822 1944 2065
140 M 1820 1960 2100 2240 2380
F 1638 1764 1890 2016 2142
145 M 1885 2030 2175 2320 2465
F 1696 1827 1957 2088 2218
150 M 1950 2100 2250 2400 2550
F 1755 1890 2025 2160 2295
155 M 2015 2170 2325 2480 2635
F 1813 1953 2092 2232 2371
160 M 2080 2240 2400 2560 2720
F 1872 2016 2160 2304 2448
Desirable Very Sedentary Mod. Super
Weight Sex Sedentary Active Active Active
165 M 2145 2310 2475 2640 2805
F 1930 2079 2227 2376 2524
170 M 2210 2380 2550 2720 2890
F 1989 2142 2295 2448 2601
175 M 2275 2450 2625 2800 2975
F 2047 2205 2362 2520 2677
180 M 2340 2520 2700 2880 3060
F 2106 2268 2430 2592 2754
185 M 2405 2590 2775 2960 3145
F 2164 2331 2497 2664 2830
190 M 2470 2660 2850 3040 3230
F 2223 2394 2565 2736 2907
Activity levels are defined as follows:
Very Sedentary: Limited activity, confined to a few rooms or a house. Slow walking, no running. Most major activities involve sitting.
Sedentary: Activities involve mostly walking or some sporadic slow running at a jogging speed of approximately ten minutes per mile. Recreational activities include bowling, fishing, target shooting, horseback riding, motor boating, snow mobiling, or other similar activities. Less than ten minutes of continuous running (faster than a jog) per week.
Moderately Active: Activities include golf (eighteen holes), doubles tennis, sailing, pleasure swimming or skating, aerobic dancing, Jazzercise, downhill skiing, or other similar activities. Between ten and twenty minutes of continuous running at least three times per week.
Active: More than twenty minutes of sustained activity, such as jogging, swimming, competitive tennis, or cross-country skiing, more than three times per week or more than forty-five minutes of recreational tennis, paddle ball, or other activities at least three times per week.
Super Active: At least one and a half-hour of vigorous activity (training for competitive athletics, full-court basketball, mountain climbing, weight training, football, wrestling, or other similar activity) four days per week or more than two and a half hours of recreational activity four or more times per week.
To summarize, obesity occurs when the body is taking in more energy than it is expending. This condition can occur in anyone consuming enough calories. In most obese individuals, however, it occurs at caloric intakes that are not greater than the caloric intakes of lean individuals. The obese person may handle calories more efficiently. Hence, at the same caloric intake as a lean person, he or she will have an excess that becomes fat! To treat obesity, we must reduce the number of calories consumed or increase the amount of physical exercise (or both). As yet, we are unable to alter the body’s metabolism safely to make it a less efficient calorie converter.
Thus, the treatment of obesity does not really get at the core of the problem. In order to reduce caloric intake we must decrease an appetite that may be perfectly normal. This is not an easy task. We must try to alter the pattern of food intake and the kind of foods eaten, a system that may be deeply rooted in religion, ethnicity, and family background. Finally, we can increase the amount of exercise. This approach is an excellent one in the prevention of obesity but of limited use in its treatment.
Is it any wonder that more people are cured of even the most malignant type of cancer than are permanently cured of obesity? What happens, then, to those people not cured of obesity? Is it worth the effort a person must go through? Is our society too concerned about being overweight? Is the billion-dollar-a-year diet industry producing any effect on our health?
In order to answer these questions, let us examine the health consequences of obesity:
1. Obesity increases our chances for developing three of the major risk factors for atherosclerosis: high blood pressure, high blood levels of cholesterol, and diabetes. In addition, obesity directly increases our risk for gall bladder disease and for certain forms of cancer. Thus, obesity can lead to premature death—directly and indirectly.
2. Obesity by itself can cause health liabilities such as shortness of breath, sleep apnea, increased risk for any surgical procedure, and a greater propensity for certain kinds of accidents.
3. Obesity will result in major restrictions on a person’s living habits and interfere with the quality of life. The obese individual is a member of an oppressed minority. He or she is often viewed by society as deformed through his or her own gluttony.
It is ironic that the third problem, which in many ways is the most serious an obese person faces, is not his or her fault but that of the society in which he or she lives. In Polynesia, if you are obese, you are worth your weight in gold. In the United States, at best, society pities you. As we shall see, the health risks attributed to overweight, while real, are minimal for most people. If only those people who are truly obese and at increased risk for major health problems were to undertake serious weight-reduction schemes, a billion-dollar diet industry would shrink to nothing and book publishers would be in financial trouble. Let us therefore examine obesity as a major health risk.
We have already defined obesity as 20 percent above our ideal weight. In this section we are not discussing the person who is five, ten, fifteen, or even twenty pounds overweight. If you should weigh 150 pounds, you are obese at 180 pounds. If you should weigh 180 pounds, you are obese if you weigh 216 pounds.
There is no evidence that people who are overweight but not obese are at any significantly increased risk for any of the major diseases listed above. Your ideal weight is the weight that offers you the greatest longevity. Statistically, the risk curve rises sharply only after we are well into the obesity range. For practical purposes, then, you should be concerned about overweight potentially shortening your life when you approach the obesity range. If you are 10 to 20 percent above ideal weight, you are in a caution zone. If you are in this zone, you do not necessarily need to lose weight. It is much more important that you don’t gain any more weight. A person who is 10 percent above ideal weight and has been that way for ten years may need only to keep careful watch on his or her weight. By contrast, a normal person whose weight begins to creep up slowly but steadily and approaches the 10 percent mark should begin an active program to stop any further weight gain.
Once we have reached the obesity range, our risk for the abnormalities and diseases listed above increases. But the risk does not increase linearly the heavier we get. At most, there is a small increase in risk until we are moderately to severely obese. The number of pounds we can sustain before this sharp increase occurs will vary from person to person and with the abnormality or disease in question. Thus, we may have to be forty pounds overweight before our risk for high blood cholesterol has increased significantly, and perhaps thirty pounds for high blood pressure or diabetes. If you are at the lower end of the spectrum, though technically obese, your risk may not increase very much. We do not mean to say that if you are mildly obese, don’t worry about it. What we are saying has very practical value in weight reduction. The most important objective of any weight-reduction program should be to lower our risk for the diseases we have discussed. It is much more important for us to lose enough weight to change our risk category than it is to reach an “ideal” weight.
One major reason that most reducing programs fail is because we set inappropriate goals. For the man whose ideal weight is 180 but who weighs 240, a loss of twenty-five pounds may reduce his risk markedly even though it won’t change his physical image very much. Most important is that a loss of twenty-five pounds may be attainable and sustainable. If he attempts to lose forty or fifty pounds, he will most likely fail and wind up frustrated.
Atherosclerosis, hypertension, and diabetes are the three major killer diseases to which obesity makes a significant contribution. (Obesity also increases the risk slightly for a few rare cancers.) As we have seen in Chapters 2 and 3, atherosclerosis and hypertension both involve multiple risk factors. We shall see in Chapter 5 that the same holds true for diabetes. The nature of obesity’s contribution to the risks for these major diseases is still not entirely clear. The distribution of excessive body fat is also significant. In general, people with excessive fat below the waist line (pear shaped) are at lower risk than those with excessive fat above the waist (apple shaped). Sex hormones play an important role in distribution of body fat, and men more often exhibit large abdomens while women accumulate fat in the hips and thighs.
Careful analysis of available data has led some experts to believe that obesity is important only if we already have a genetic predisposition to the diseases, and only if we are severely obese. If you fall into this category, you are at high risk and should make every effort to lower your weight sufficiently to reduce that risk. If you do not fall into this category and are not very obese, while there is no room for complacency, weight reduction may be less of an emergency.
Many of us are above our ideal weight, but not all of us in that category are obese. Before considering a crash diet, assess your personal condition. Are you obese? If so, how obese? Do you have a positive family history for atherosclerosis, high blood pressure, or diabetes? Are you in the danger zone? Only after you have answered these questions honestly can you decide whether weight reduction will improve your health and how much adjustment is necessary in your particular case.
Perhaps with no other disease is the old adage “An ounce of prevention is worth a pound of cure” as true as with obesity. It is, therefore, well worth the trouble to assess our risk for becoming obese and, if we are in danger, to do something about it. As we have seen, there is a strong genetic component to obesity. Therefore, family history is important. If your family health tree shows obesity, your own tendency to become overweight increases. Even if there is no history of obesity in your family, a careful examination of the rest of your propensities is still important. Since obesity is particularly hazardous when coupled with a genetic inclination for high cholesterol levels, high blood pressure, or diabetes, a history of any of these conditions in our family background makes obesity more dangerous. While a positive family history for any or all these abnormalities may not increase our risk, conversely, if we do become obese, our risk for heart attack or stroke will increase.
If you were obese as a child, you are at increased risk of being obese as an adult. You must consider yourself at risk even if your weight is normal. Beyond your own history and your family background, consider your lifestyle. Are you becoming more sedentary because of your age, your job, or just because of a new way of life? Are you a compulsive eater whose appetite is triggered by external cues, especially during periods of tension? Have you increased your consumption of alcohol, a major source of hidden calories? If the answer to any of these questions is yes, you are at increased risk. Finally, if you are a woman and have children, did you gain a little weight permanently after each pregnancy? Do premenstrual tensions result in your eating more? If the answer is yes, your risk increases. To get a numerical rating of your risks for obesity, evaluate:
First, your present weight: if you are 10 to 20 percent above ideal weight, you are in the danger zone, and you should score 5.
Second, your family history on a scale of 1 to 5: if your family health tree is abundant with obese relatives, score 3; if your father or mother was obese, score 4; if both parents were obese, score 5.
Third, your own history: if you were truly obese as a child, score 5. If you have always had a problem controlling your weight, score 3.
Fourth, your lifestyle: if you are a compulsive eater, score 2 to 5, depending on how much tension you are under and how much food you consume during periods of tension. If you are a moderately heavy drinker, add 2. If you live a moderately sedentary life, score 2; if you do almost no exercise, score 4. If you are a woman and have been getting heavier with each pregnancy, add 2.
A score of 5 or more places us at risk for obesity. As our score increases, our risk rises; but anyone scoring 5 or above should take measures to prevent obesity. If you suffer from atherosclerosis, or have high blood-cholesterol levels or high blood pressure or diabetes, you should start preventive measures, even if you are of normal weight. It is also good advice to use preventive measures even if you do not suffer from those diseases but do have a strong family history for one or more of them. Again, your risk for obesity may not be high; but the potential for becoming obese is greater.
There is no specific number of calories that must be consumed to prevent obesity. The right number for you may be too much for your friend, even though you are both of the same age, gender, and body build. You have to find your own level. Begin by checking your weight several times a week. If it is stable and you are not in the danger zone, check it once a week. Note the amount of food you take in and estimate your average daily caloric intake. As long as it remains stable, no other measures are necessary. If your weight begins to increase, even by one or two pounds, recalculate your caloric intake. If your intake has gone up, cut back to where it was before. This may be difficult if your eating pattern has changed. It may require some modifications. By using some simple measures you may nip a potentially serious problem in the bud.
If you are in the danger zone (10 to 20 percent above ideal weight) and your weight is stable, you need to lose some pounds; but you have plenty of time in which to do it. You can decrease the number of calories you consume, increase the amount of physical activity you perform, or both. Don’t go on a crash program; you will just bounce back after you stop. Most Americans on crash diets at any given time are either in the caution zone or are even less overweight. Only a few are obese. Remember that you are not at increased health risk. You should lose some weight to prevent yourself from becoming obese later in life when there is a tendency to gain more weight. If you take your time making a few changes in your diet and your lifestyle and aim for any weight loss that you can comfortably sustain, you are more likely to succeed in losing those pounds.
Certainly, you will have to reduce the number of calories you take in. The best way to do this is to identify the sources of calories in your diet that contain the lowest nutrient value. The principle we wish to convey is not to go on any special diet but rather to modify the one you are on now to reduce the number of calories in it without affecting the amount of nutrients it contains. If your diet has been poorly balanced to start, it may still be poorly balanced and probably should be changed. The time to change it is after you have reached the proper caloric level and sustained that level for several months. The less radical the changes as you begin to limit your calories, the better.
What contributes the unwanted calories in our diets depends on our individual habits. For some of us, it may be beer or other alcoholic beverages; for others, refined sugar or chocolates; for others, fat; and for many, all three. There are some general rules to help us decide what foods or beverages to eliminate or reduce in quantity. Fat has twice the number of calories per gram as sugar. Thus, eliminating a given quantity of fat reduces our calories twice as much as eliminating the same amount of sugar. Suppose you consume 2,500 calories per day from the following foods: whole milk, toast and butter, coffee (three cups a day) with two teaspoons of sugar, tuna fish or chicken salad sandwich, steak, home-fried potatoes, vegetables, salads, and cheese-cake or apple pie—a standard American diet. In addition, you have one martini before dinner and a glass or two of wine with dinner.
You want to reduce your intake to 2,200 calories. What are your options? First, identify those sources of calories that have little or no nutrient value:
Alcohol—Cutting out the martini will save calories.
Sugar—Eliminating the sugar from your coffee or substituting a non-caloric sweetener saves calories.
Fat—Carefully trimming your meat and having a baked potato may save calories (if you don’t add butter or sour cream to the potato).
Combined fat and sugar—Replacing the cheesecake or apple pie with a piece of fruit can reduce our caloric intake by more than 100 calories.
The number of ways in which we can eliminate 300 calories from our diet and still keep the nutrient values the same is almost infinite. Just be aware of what you are eating and initiate the kind of changes that are easiest for you. Your main goal is to reach the caloric level that will begin to bring about weight reduction.
Be sure to incorporate balance into your menus. To attain rigid control of you calorie count, use the exchange lists explained in Chapter 5. Start with the normal number of calories you eat in a day and then divide by 300. If you normally eat 1,200 calories a day, you should limit your fat intake to 40 grams of fat. For 1,500 calories, it is 50 grams; for 1,800 calories, 60 grams; for 2,000 calories, 66 grams; and for 2,500 calories, 83 grams. By staying within these guidelines, you will be able to keep to the limit of 30 percent of calories from fat. Do not try to reduce your fat calories to less than 30 percent without professional help. Some fat in our diets is important for its satiety value, for flavor enhancement and as a media for some of the essential nutrients. Excessive use of “fat free” products is a potential hazard to your health.
Sometimes the number of calories we consume can begin to creep up because of a change in our lifestyle. For example, a job promotion could make it necessary to entertain clients at lunch once or twice a week. Likewise, eating in the company cafeteria instead of the executive dining room can increase our caloric intake enough to result in a slow weight gain. Be alert to this possibility. If you do begin to gain, cut your calories back to the previous level. This doesn’t mean you have to give up your new lifestyle. It means you have to adapt it to the number of calories that maintain your own weight at a healthy level. Maybe ordering differently at lunch is the answer, or perhaps modifying your dinner, or both. Choose whatever methods work best for you. Once your caloric intake is at its previous level and you have shed the extra pound or two, maintain this pattern of eating while continuing to weigh yourself several times a week. Usually you will have stabilized at your previous weight and will have averted a potentially serious weight problem.
Changes in lifestyle often occur so subtly that they go unnoticed for a long time. Sometimes these changes are accompanied by significant weight gain. The gradual shift from the active exercise pattern of high school and college to the less active pattern of a young man or woman entering the workforce can often result in a weight gain. Increasing our alcohol intake, giving up smoking, traveling more often for business or pleasure, all may be accompanied increased caloric intake and gradual increases in our weight. In today’s hectic pace of life the American people are not getting enough sleep, and that changes our eating habits. We tend to eat more for comfort or to wind down after a stressful day. If you are at risk for obesity, you should be always on the alert for these changes. Anticipate them and adjust your calorie intake accordingly.
Finally, certain activities are usually accompanied by eating. Who can go to the movies without eating some popcorn? A baseball game is not complete without a hot dog or soft drink. Part of going to the theater is the coffee and pastry we have after the show. All these activities enrich our lives. To suggest giving them up is neither necessary nor practical. If they occur only occasionally, don’t worry. If they form a regular and frequent part of your life, then the calories you consume at these events must be considered as part of your daily calorie intake. It is important for us to be aware of what we are eating. We can change the pattern in a way that preserves the social event and at the same time eliminates unwanted calories.
Perhaps watching television is the most significant sedentary activity contributing to obesity. For many of us, it is also a time for unconscious eating. Finally, at least half the commercials are for food or beverages. Analyze your television viewing time. Are you a beer and pretzels football game spectator? Do you nibble on candy or crackers throughout your favorite program? For several evenings, write down everything that you eat as you watch. Then calculate the calories: how many? 500? 750? Find a way to bring that number down. Put the peanuts on the top shelf of the closet. Substitute fruit for pretzels, and juice or sugar-free iced tea for beer. You don’t need a prescribed plan to tell you how to reduce your television calories. You only need to be aware that you are consuming calories as you watch. You need to know how many you are consuming; and you need determination to alter the pattern and reduce your caloric intake. There is no single best way. If one method fails, try another. Use any method that works for you, but control the amount and kind of food. Keep the number of calories to a level that sustains your weight and prevents it from creeping up.
Between the ages of twenty-five and fifty, Americans do not increase their food intake to any great extent. Yet, we all tend to gain weight. Do you eat more now than when you were twenty-five? If anything, you probably eat less. This gain is due partly to changes in our metabolism; but, mainly, it results from a steady decline in physical activity in the normal course of the day. Many opportunities can easily go unnoticed. Simply walking a few miles a day or taking the stairs instead of the elevator can make a big difference. The key is regularity. We should make exercise part of our regular daily habits. We need to introduce more activity into each routine. This may be the greatest challenge any of us face in our struggle to prevent obesity.
Regular physical activity will increase both our caloric expenditure and our physical fitness. Some of us jog or walk briskly every day. Some people play tennis, others work out in gyms, but whatever activity it is, it should be done on a regular basis. It must become an integral part of our lifestyle. Therefore, it is essential that we enjoy it. Don’t run because everyone else does. If running bores you, you’ll never sustain it. Besides, running may be too hard on your joints. Even Dr. Cooper, the “father of aerobic exercise,” now feels that he overdid himself in his early years of zest. If you like to dance, do it regularly. Take a daily walk to the post office, the supermarket, or a friend’s house. Ride a bicycle; swim, if you have access to a pool. Any of these activities will consume calories. The best one is not the one that consumes the most calories but the one you can make a part of your daily routine. Whatever you do, your bathroom scale will measure your success. But the scales alone won’t tell the full story of your exercise program. Because muscle tissue is denser than adipose tissue, you can gain weight while losing fat. This is particularly true of “body building” exercise. You can, theoretically, lose two inches in your belt line while gaining twenty pounds on the scales. You are simply changing fat to muscle.
Two major incentives must be kept in mind in treating obesity:
1. You wish to reduce your body weight to a range that lowers your risk for the complications of obesity.
2. You wish to start preventive measures against atherosclerosis, high blood pressure, diabetes and other disorders that are more common in obese people.
Unfortunately, true obesity is an affliction that will most likely plague you the rest of your life. Most obese people have tried many plans, lost and regained hundreds of pounds, with little permanent success in controlling their weight. Therefore, while it is important that you lose weight, it is equally important that you accept the possibility that you may always be obese. Try to protect yourself from its complications.
Just as there is no perfectly safe and effective pill for obesity, there is no such thing as the “perfect diet” which will take off thirty pounds in three weeks. Such a diet does not exist! For an obese person to lose significant weight and to keep it off means a lifetime of hard work. However, we can give you some tips that might help lessen the burden of constantly watching your diet. Remember that you may not be an overeater. Instead, you may be an under-user of calories. This means that, for you to lose weight, you may have to reduce your number of calories to a level below that which a non-obese individual would have to consume. The number of calories we can take in while still losing weight will vary from person to person. For some obese subjects, 2,000 per day will achieve weight loss; for others, 1,500; for some, 1,200 or even less. Find your level and construct your own diet by eliminating fat, sugar and alcohol, and by using foods whose caloric value totals the necessary number of calories per day. If you find that you must consume 1,500 calories or less to begin a slow but steady weight loss, take a multivitamin and mineral supplement. Any brand that gives you the Recommended Daily Intake of B vitamins, vitamin C, iron, zinc, and calcium is right.
Continue at this caloric level until you stop losing weight. This plateau will often occur after two to three weeks. Your initial weight loss is partly water, and the resulting tissue dehydration is correcting itself. You are still losing fat tissue, but the scale isn’t showing it because you are replacing water. Be patient! In another week, after you re-hydrate, you will begin to lose weight again. After a few weeks, you may reach another plateau. Your metabolism is fighting you by increasing its efficiency. This is time to fight back. Reduce your caloric intake by another 100 to 200 calories. Your weight will begin to decrease again.
The procedure we have outlined does not take two weeks or two months. It takes much longer: six months, nine months, or twelve months, depending on how obese you are and also on your metabolism. Remember that your primary goal is not to achieve ideal weight but one that will minimize the risks of obesity. Any weight that is below the danger zone is excellent. Even if this results in your remaining within the danger zone, you are much better off than you were before.
Here is an example: Suppose you weigh 250 pounds and your ideal weight is 180 pounds; 110 percent of your ideal weight would be 198 pounds, so at 216 pounds you are obese. Thus, to reach ideal weight, you must lose seventy pounds and maintain that weight loss. To be below the danger zone you have to lose fifty-two pounds and maintain that weight. To be no longer obese you will have to lose thirty-four pounds. Thus, you need to lose half as much weight to be no longer obese than to achieve your ideal weight. However, by losing those thirty-four pounds you may reduce your risk for the complications of obesity by 40 percent or more. The next thirty-six pounds will only reduce your risk by an additional 15 to 20 percent. Certainly, it would be best for you to achieve and maintain your ideal weight, but experience has taught us that this goal is almost unattainable. Therefore, you should set a goal you can achieve and which eliminates the major portion of your risk.
Maintain that weight until it becomes your new stable level. Then if you wish to take off more and can succeed, you will have reduced your risk a little more and obtained important cosmetic and psychological effects to boot. If you fail and return to your new baseline, you will still be at much lower risk than when you started. Keeping your weight stable with the least amount of caloric restriction possible is easier if you are active. Therefore, when you reach your desired goal, begin a moderate exercise routine that can be incorporated along with your new eating habits. Exercise will not only help you keep your new weight, but may directly reduce your risk for atherosclerosis and hypertension and their dreaded complications—heart attack or stroke.
The best way for any of us to minimize the risks of obesity is to lose sufficient weight that we are no longer obese. Unfortunately, even if they set proper goals, many obese people will not or cannot permanently reduce their weight. These people are at increased risk for several diseases, including high blood pressure and atherosclerosis, which can be influenced by diet. If you are obese and have not been able to reduce your weight, you should be constantly alert for these diseases. Your blood pressure should be taken at least twice a year and your serum lipids should be analyzed with the same frequency. If you have a serum cholesterol above 200, you should alter your diet as set forth in Chapter 2. If you are a male with a family history of atherosclerosis and you are obese, you should consume a low-fat diet even if you have no other risks for atherosclerosis. If you are a female with marked obesity (30 percent or more above ideal weight) with a positive family history for atherosclerosis, you should similarly modify your diet.
As for hypertension, obesity itself is reason enough to reduce the amount of salt in our diet (see Chapter 3). If you are African-American or have a family history of high blood pressure, you must be even more careful about your salt intake.
Beyond these dietary changes, it is important to have your blood pressure carefully monitored. It may go up even if you modify your salt intake. Today, very effective drug therapy exists for hypertension (high blood pressure). The key is to begin early. This can be done only if you are aware that your blood pressure is high. If you are obese, you are more at risk for hypertension, and therefore must take special pains to start controlling this disease as early as possible.
Once you have achieved you goal in weight reduction (whether by “sensible dieting,” “crash dieting” or with a “miracle drug”), place more emphasis on healthy eating patterns for you and your family, i.e., your maintenance program. The following guidelines will help you maintain proper balance in your daily menu plans:
Eat 6 to 11 servings per day of whole grain, enriched breads, cereals and other grain products. One serving equals 1 slice of bread: 1/2 hamburger bun; 1/2 English bun; a small roll, biscuit or muffin; 3 to 4 small crackers; 2 large crackers; ½ cup cooked cereal, rice or pasta; 1 ounce of ready-to-eat cereal.
Eat 2 to 4 servings per day of fruits (citrus, melon, berries and other fruits). One serving equals a whole fruit such as a medium apple, banana or orange; ½ grapefruit; a wedge of melon; ¾ cup of juice; ½ cup of berries, ½ cup of cooked or canned fruit, ¼ cup dried fruit.
Eat 3 to 5 servings per day of vegetables (dark green leafy, deep yellow, dried beans and peas or legumes, starchy and other vegetables.) Include a wide variety by eating from all five vegetable subgroups (dark green, bright yellow, legumes, starchy vegetables, and other vegetables), but make sure to use dark green leafy vegetables and dried beans and peas several times a week. One serving equals ½ cup of cooked vegetables; ½ cup of chopped raw vegetables; or 1 cup of leafy raw vegetables such as lettuce or spinach.
Eat 2 to 3 servings per day of meat, poultry, fish or vegetarian alternates such as eggs, dried beans and peas, nuts and seeds. Try to limit this to about 5 to 7 ounces of cooked lean meat, poultry or fish each day. One ounce of meat equals 1 egg; ½ cup cooked beans; 2 tablespoons of peanut butter.
Eat 2 servings per day of milk, cheese and yogurt. Try to stick to the low-fat or no-fat varieties. Women who are pregnant or breast-feeding, as well as teenagers, should get 3 servings per day. Pregnant or breast-feeding teenagers should increase this to 4. 1 serving equals 1 cup of milk; 8 ounces of yogurt; 1 ½ ounces of natural cheese; 2 ounces of processed cheese.
Fats, oils, sweets and alcoholic beverages should be consumed sparingly.
If 3 to 5 servings of vegetables and 6 to 11 servings of “grains” seems like a lot to you, remind yourself that these are not the serving sizes that you are accustomed to. You can include multiple servings of one or two foods. When you have “seconds,” (or if you eat two slices of bread, instead of one) that doubles the number of servings in the pertinent food category. However, “Variety is the spice of life!” Eat as many different foods as you can. Limit the meat items, milk fat and other fatty foods.