Commercial Weight Loss Programs.  This report cannot possibly address the many commercial and nonprofit weight-loss programs currently available or assess their claims. Most of the commercial programs, such as Weight Watchers, Jenny Craig, and NutriSystem offer lifestyle changes and packaged meals. Most tend to be expensive and have not publicized their results.

Commercial Meal Replacements. Studies are reporting good success with meal replacement beverages (Slim-Fast, Sweet Success). They contains major nutrients needed for daily requirements, each serving typically contains between 200 to 250 calories and replaces one meal. (Using them for all meals reduces calories to a severe extent and can be harmful.) One reported that most subjects who had undergone a 12-week weight loss program and then used Ultra Slim Fast supplements as directed for maintenance kept off more than half their weight loss after more than three years. A quarter of the subjects was still losing weight.

Exercise
As people age, they need to exercise more to keep off the same amount of weight. In spite of this, a 2001 study reported that over half of American adults either do not exercise regularly or at all. Exercise, which replaces fat with muscle, is the critical companion for any weight control program. Moreover, exercise improves overall health. In fact, a British study found that overweight fit individuals have half the death rate of unfit trim individuals. Studies show that exercise has the following benefits:

 
• burns calories  
• improves metabolism  
• suppresses appetite  
• lowers risk for coronary artery disease and high blood pressure  
• improves insulin sensitivity

It should be noted that because obesity is so often related to heart and other diseases, anyone who is overweight must discuss their exercise program with a physician before starting. The following are some suggestions and observations on exercise and weight loss:

 
• Most experts recommend building up to 45 to 60 minutes a day of mostly aerobic exercise, such as hiking, brisk walking, or energetic dancing.  
• The treadmill burns the most calories, and may be particularly effective when used in short multiple bouts during the day. In fact, frequent exercise sessions as short as 10 minutes in duration may be the most successful program for obese people.  
• Although even vigorous workouts do not immediately burn great numbers of calories, the metabolism remains elevated after exercise, and the more strenuous the exercise, the longer the metabolism continues to burn calories before returning to its resting level. This state of elevated metabolism can last for as little as a few minutes after light exercise to as long as several hours after prolonged or heavy exercise.  
• Resistance, or strength training should be included in any regimen. If performed two or three times a week, it is excellent for replacing fat with muscles.  
• Fidgeting may be very helpful in keeping pounds off. Regular exercise is certainly the best course, but for people who must sit for hours at work, frequently shifting positions while sitting may have some benefit. (One study even suggested that chewing gum helps increase energy expenditure.)  
• Exercise improves psychological well being and replaces sedentary habits that usually lead to snacking. Exercise may even act as a mild appetite suppressant. People who exercise are more apt to stay on a diet plan.  
• It is important to realize that as people slim down, their initial level of physical activity becomes easier and they burn fewer calories per mile of walking or jogging. The rate of weight loss slows down, sometimes discouragingly so, after an initial dramatic head start using diet and exercise combinations. People should be aware of this phenomenon and keep adding to their daily exercise regimen.

Behavioral Approaches
Cognitive-Behavioral Therapy. The goal of cognitive-behavioral therapy is to change the daily patterns associated with eating; it is very useful for preventing relapse after initial weight loss. It may work as follows:

 
• The patient first records in a diary all activity related to eating patterns, including the times of day, length of meal, emotional states, companions, and, of course, the kind and amounts of food eaten. (Patients tend to underreport their dietary intake, but it is still a good method for increasing their awareness of eating patterns.) One patient said that recording circumstances surrounding relapses was a particularly valuable guide for understanding the stresses leading to her own eating behaviors.  
• The therapist and the patient review the diary to set realistic goals and identify patterns that the patient can change. For instance, if food is normally eaten while watching television, then the patient may be advised to eat in another room instead.  
• Good eating habits are reinforced by rewards, other pleasures that substitute for high calorie consumption and sedentary activities.

Behavioral modification has been shown to be helpful particularly for people who have an overly strong response to the taste, smell, and appearance of food.

Behavioral Support Groups. Overeaters Anonymous, or TOPS (Take Off Pounds Sensibly) are nonprofit support groups that offer behavioral methods and support for losing weight and maintaining weight. Some Internet web sites now offer interactive behavioral programs that appear to be effective.