The term “weight management” embodies a change in thinking about the treatment of people with excess body weight or obesity during the past 20 years. Before 1980, treatment of overweight people focused on weight loss, with the goal of helping the patient reach an “ideal weight” as defined by standard life insurance height-weight charts. In recent years, however, researchers have discovered that most of the negative health consequences of obesity are improved or controlled by a relatively modest weight loss, perhaps as little as 10% of the patient’s body weight. It is not necessary to reach the “ideal” weight to benefit from weight management. Some nutritionists refer to this treatment goal as the “10% solution.” The fact that most obese people who lose large amounts of weight from reduced-calorie diets regain it within five years has led nutrition experts to emphasize weight management rather than weight loss as an appropriate outcome of treatment.
The purpose of weight management is to help each patient achieve and maintain the best weight possible in the context of overall good health. It also involves the prevention and treatment of diseases associated with obesity or with eating disorders.
Overweight and obesity
Being overweight and obese is not the same thing. People who are overweight weigh more than the recommended standard for their height. The excess weight may come from muscle tissue, body water, or bone, as well as from fat. A person who is obese has too much fat in comparison to other types of body tissue; hence, it is possible to be overweight without being obese.
There are a number of methods that can be used to determine whether a person is obese. One method is based on the relationship between height and weight. The older measurements of this correlation are the so-called height-weight tables that list optimum weights for a given height. A more accurate measurement of obesity is the body mass index, or BMI. The BMI is an indirect measurement of the amount of body fat. The BMI is calculated by multiplying a person’s weight in pounds by 703.1, and dividing that number by the person’s height in inches squared. A BMI between 19 and 24 is considered normal; 25–29 is overweight; 30–34 is moderately obese; 35–39 is severely obese; and 40 or higher is defined as morbidly obese. More direct evaluations of body fat include measuring the thickness of the skin fold at the back of the upper arm, and bioelectrical impedance analysis (BIA). Bioelectrical impedance analysis measures the total amount of water in the body using an instrument that calculates the different degrees of resistance to an electrical current in different types of body tissue. Fatty tissue has a higher resistance to the current than body tissues containing larger amounts of water. A higher percentage of body water indicates a greater amount of lean tissue.
Demographics and statistics
Obesity has become a major public health concern in the developed world in the last decade. As of 2003, obesity ranks second only to smoking as a major cause of preventable deaths. It is estimated that 300,000 people die in the United States each year from weight-related causes. The proportion of overweight adults in the general population has continued to rise since the 1960s. About 34% of American adults, or 58 million people, are currently overweight. In addition, there has been a 42% increase in the rate of childhood obesity since 1980.
The rate of obesity increases as people age; those aged 55 or older are more than twice as likely to be obese as those in their twenties. African American men have the same rate of obesity as Caucasian men; however, African American women are almost twice as likely as Caucasian women to be obese by the time they reach middle age. The same ratio holds true for socioeconomic status; people in the lowest third of the income and educational level distribution are twice as likely to be obese as those with more education and higher income. From the economic standpoint, obesity costs the United States over $100 billion each year.
Obesity is considered responsible for:
• 90% or more of cases of type 2 diabetes
• 60% or more of cases of coronary heart disease
• 70% of gallstone attacks
• 35% of cases of hypertension
• 11% of breast cancers
• 10% of colon cancers
In addition, obesity intensifies the pain of osteoarthritis and gout; increases the risk of complications in pregnancy and childbirth; contributes to depression and other mental disorders; and increases the complexity of many surgical procedures. Many surgeons refuse to operate on patients who weigh more than 300 lb (136 kg).
Although fewer people suffer from eating disorders than from obesity, the National Institutes of Mental Health (NIMH) reports that 10 million adults in the United States meet the diagnostic criteria for anorexia or bulimia. Although eating disorders are stereotyped as affecting only adolescent or college-aged women, as of 2003 at least 10% of people with eating disorders are males—and the proportion of males to females is rising. Moreover, the number of women over 45 years of age who are diagnosed with eating disorders is also rising; many doctors attribute this startling new trend to fear of aging, as well as fear of obesity.
At least 50,000 people die each year in the United States as the direct result of an eating disorder; anorexia is the leading cause of death in women between the ages of 17 and 25.
Causes of nutrition-related disorders
Genetics. Studies of twins separated at birth and genetic research in the laboratory point to a genetic component to obesity. Some researchers think that there are also genetic factors involved in eating disorders.
Lifestyle. The ready availability of relatively inexpensive, but high-calorie snacks and “junk food” is considered to contribute to the high rates of obesity in developed countries. In addition, the fast pace of modern life encourages people to select easily prepared processed foods that are high in calories, rather than eat healthy meals that take longer to prepare. Changes in technology and transportation patterns mean that people today do not do as much walking or hard physical work as earlier generations did. This inactive lifestyle promotes weight gain.
Advertising. In recent years, many researchers have examined the role of advertising and the mass media in encouraging unhealthy eating patterns. On the one hand, advertisements for such items as fast food, soft drinks, and ice cream, often convey the message that food can be used to relieve stress, comfort, and reward. At the other extreme, the media can portray unrealistic images of human physical perfection. The emphasis on thinness as an essential component of beauty, particularly in women, is often cited as a major factor in the increase in eating disorders over the past three decades.
Medications. A number of prescription medications can contribute to weight gain. These drugs include steroids, hormones, antidepressants, benzodiazepine tranquilizers, lithium, and antipsychotic medications.
Weight management programs
Since the late 1980s, nutritionists and health care professionals had come to recognize that successful weight management programs have three characteristics:
- Presentation of weight management as a lifetime commitment to healthy patterns of eating and exercise, rather than emphasis on strict dieting.
- Programs tailored at an individual level to age, general health, and life style.
- Recognition that the emotional, psychological, and spiritual aspects of human life are as important to maintaining a healthy lifestyle as medicine and nutrition facets.
Diet. Most weight-management programs are based on a daily diet that supplies enough vitamins and minerals; 50–63 grams of protein; an adequate intake of carbohydrates (100 g) and dietary fiber (20–30 g); and no more than 30% of daily calories from fat. Good weight-management diets are intended to teach people how to make wise food choices and to encourage gradual weight loss. Some diets are based on fixed menus, while others involve food exchanges. In a food-exchange diet, it is possible to choose several items within a particular food group when following a menu plan. For example, if a person’s menu plan allows for two items from the vegetable group at lunch, they can have one raw and one cooked vegetable, or one serving of vegetable juice along with another vegetable. More detailed information about these and other weight-management diets is available in a booklet from the Weight Information Network of the National Institutes of Health, called Weight Loss for Life.
Nutritional counseling. Nutritional counseling is important in successful weight management because many people do not understand how the body utilizes food. They may also be trying to manage their weight in unhealthy ways. One recent study of adolescents found that 32% of the females and 17% of the males were using such potentially dangerous methods of weight control as smoking, fasting, over-the-counter diet pills, or laxatives.
Exercise. Regular physical exercise plays a major role in weight management because it increases the number of calories used by the body and stimulates the body to replace fat with lean muscle tissue. Exercise can also lower emotional stress levels and promote a general sense of well-being. A doctor should be consulted before beginning an exercise program, however. Good choices for most people include swimming, walking, cycling, and stretching exercises.
Cognitive-behavioral therapy. Cognitive-behavioral therapy (CBT) is a form of psychotherapy that has been demonstrated to be effective in reinforcing the changes in food choices and eating patterns that are necessary to successful weight management. In this type of therapy, patients learn to alter their eating habits by keeping diaries and records of what they eat, what events or feelings trigger overeating, and any other patterns that they notice about their choice of foods or eating habits. They also examine their attitudes toward food and weight management, and work to change any attitudes that are self-defeating or interfere with a healthy lifestyle. Most CBT programs also include nutritional education and counseling.
Weight-management groups. Many doctors and nutritional counselors suggest that patients attend a weight-management group for support. Social support is important in weight management, because many who suffer from obesity or an eating disorder struggle with intense emotions. Many isolate themselves from others because they are afraid of being teased or criticized for their appearance. Such groups as Weight Watchers, Overeaters Anonymous, or Take Off Pounds Sensibly help members in several ways: They help to reduce the levels of shame and anxiety that most members feel; they teach strategies for coping with setbacks in weight management; they provide settings for making new friends; and they help people learn to handle problems in their workplace or in relationships with family members.
Obesity and eating disorder medications. In recent years, doctors have been cautious about prescribing appetite suppressants, which are drugs given to reduce the desire for food. In 1997, the Food and Drug Administration (FDA) banned the sale of two drugs: fenfluramine and phentermine when they were discovered to cause damage to heart valves. A newer appetite suppressant, known as sibutramine, has been approved as safe. Another drug that is sometimes prescribed for weight management is called orlistat. It works by lowering the amount of dietary fat that is absorbed by the body. However, it can cause significant diarrhea.
People with eating disorders are sometimes given antidepressant medications, most often fluoxetine (Prozac) or venlafaxine, to relieve the symptoms of depression or anxiety that often accompany eating disorders.
Surgery. As of 2003, bariatric surgery is the most successful approach to weight management for people who are morbidly obese (BMI of 40 or greater), or severely obese with additional health complications. Surgical treatment of obesity usually results in significant weight loss that is successfully maintained for longer than five years. The most common surgical procedures for weight management are vertical banded gastroplasty (VBG), sometimes referred to as “stomach stapling,” and gastric bypass. Vertical banded gastroplasty works by limiting the amount of food the stomach can hold, while gastric bypass works by preventing normal absorption of the nutrients in the food.
Complementary and alternative medicine (CAM) approaches. Some forms of complementary and alternative medicine are beneficial additions to weight management programs. Movement therapies include a number of forms of exercise, such as tai chi, yoga, dance therapy, Trager work, and the Feldenkrais method. Many of these approaches help in the improvement of posture and body mobility. Tai chi and yoga, for example, are good for people who must avoid high-impact physical workouts. Yoga can also be adapted to a person’s individual needs or limitations with the help of a qualified teacher following a doctor’s recommendations.
Prayer, meditation, and regular religious worship have been linked to reduced emotional stress in people struggling with weight issues. In addition, many people find that spiritual practice helps them to keep a healthy perspective on weight management, so that it does not dominate other important interests and concerns in their lives.
Over-the-counter herbal preparations advertised as “fat burners,” muscle builders, or appetite suppressants sell well but should be treated with caution.
