Weight Management

The South Beach and Zone diets encourage healthy fats. They also allow certain carbohydrates. For example the Zone uses healthy carbohydrates (vegetables and dried beans) and unsaturated fats. The South Beach diet uses carbohydrates that have a lower impact on blood sugar levels. This is called a low-glycemic index. Low-glycemic foods include barley, dried bean and peas, milk, strawberries, and apples. High-glycemic foods include refined grains, white bread, white potatoes, and bananas and other tropical fruits. The glycemic index was developed for use in diabetes--not for weight loss. Nevertheless, there is some evidence that foods with low glycemic indexes may produce a feeling of fullness and so discourage further eating. As with any high-protein diets, people at risk for kidney stones or have other kidney problems should avoid these plans.

Liquid Meal Replacements

Some studies have reported good success with meal replacement beverages (Slim-Fast, Sweet Success). They contain major nutrients needed for daily requirements. Each serving typically contains between 200 to 250 calories and replaces one meal. (Note: Using them for all meals reduces calories to a severe extent and can be harmful.)

One study 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 3 years. A quarter of the subjects were still losing weight.

Magnesium and Diet

Medical evidence suggests that a diet rich in magnesium could reduce a person’s risk of metabolic syndrome, a cluster of problems including obesity, high blood pressure, and cholesterol. Metabolic syndrome can lead to diabetes and heart disease. A long-term study of thousands of Americans found that the risk for metabolic syndrome decreased in those who consumed the most magnesium from meals. The findings were published in the journal Circulation.

Support Groups and Behavioral Approaches

Commercial and Non-Profit Support Programs for Weight Loss. There are many different types of weight-loss program. (This report cannot address all of the many commercial and nonprofit weight-loss programs currently available, nor can it assess their claims.)

Taking off Pounds Sensibly (TOPS), a nonprofit support organization with many local chapters, is one of the least expensive programs, costing $20 a year.

Most of the commercial programs such as Weight Watchers, Jenny Craig, and NutriSystem offer individual or group support, lifestyle changes and packaged meals. These programs tend to be expensive. There are few well-conducted studies on these programs. One 2003 study reported modest weight loss over 2 years with Weight Watchers compared to a self-help program. There were no differences in heart risk factors.

Cognitive Behavioral Approaches. Most support programs use some form of cognitive-behavioral methods to change the daily patterns associated with eating. They are very useful for preventing relapse after initial weight loss. The following is a typical approach 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. (Most people--even professional dieticians according to one study -- tend to underreport their daily calorie 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 patient reviews the diary with a therapist or group 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. It also may be useful for binge eaters.

Stress-Reduction Techniques. Stress reduction and relaxation techniques may be helpful for some people with obesity, such as those whose weight is related to night-eating syndrome. [See In-Depth Report #31 Stress.]

Changing Sedentary Habits and Exercise

Changing Sedentary Habits. Making even small changes in physical activity can expend energy. For example, simply getting up to turn on and off the TV instead of using the remote and standing while talking on the phone may drop up to five pounds a year. Other suggestions include cooking one’s own food (instead of eating take out or fast food), walking to as many places as possible, using stairs instead of escalators or elevators, and gardening. Even fidgeting may be helpful in keeping pounds off, and, in one study, chewing gum increased energy expenditure. No one should rely on such mild activities, however, for serious weight loss. Only high levels of physical activity -- not just using up energy -- help prevent obesity.

Approach to Exercise. Exercise, which replaces fat with muscle, is the critical companion for any weight control program. In a one-year study, women who regularly averaged 3.5 days (176 minutes) of exercise each week lost significantly more weight than women who did not exercise regularly. Women who exercised more than 195 minutes a week lost nearly 7% of their abdominal fat.

People who exercise are more apt to stay on a diet plan. Exercise improves psychological well-being and replaces sedentary habits that usually lead to snacking. Exercise may even act as a mild appetite suppressant. Moreover, exercise improves overall health even with modest weight loss. In support of this, a British study found that overweight fit individuals had half the death rate of unfit trim individuals.

Be forewarned, however, that the pounds won’t melt off magically. Losing significant weight requires both intensive exercise and calorie restriction. In addition, if a person exercises but doesn't diet any actual pounds lost may be minimal because dense and heavier muscle mass replaces fat. Nonetheless, regardless of weight loss, a fit body will look more toned and be healthier. In addition, exercise benefits the heart even with modest weight loss.

The following are some suggestions and observations on exercise and weight loss:

• The more strenuous the exercise, the better the chances for short- and long-term success. With intense exercise, 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.
• The treadmill burns the most calories of standard aerobic machines. It may be particularly effective when used in short multiple bouts during the day. In fact, exercise sessions as short as 10 minutes in duration that are done frequently (about four times a day) may be the most successful program for obese people.
• Resistance, or strength, training is excellent for replacing fat with muscles. It should be performed two or three times a week.
• 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.
• As people age, they also need to exercise more to keep off the same amount of weight.
• Changes in fat and muscle distribution may differ between men and women as they exercise. Men tend to lose abdominal fat (which lowers their risk for heart disease faster than reducing general body fat). Exercise, however, does not appear to have the same effect on weight distribution in women. In one interesting study women who underwent aerobic and strength training lost fat in their arms and trunk, but did not gain muscle tissue in these regions. On the other hand, they gained muscles but achieved no change in fat mass in their legs.

Warning Note. Because obesity is one of the risk factors for heart disease and diabetes, anyone who is overweight must discuss their exercise program with a physician before starting. Sudden strenuous exercise, in such cases, can be very dangerous.[See In-Depth Report #29 Exercise.]