Several studies have shown that long-term weight loss lowers blood pressure in people who are obese, and high blood pressure is a known risk factor for heart attacks and strokes. In one study, obese subjects who lost weight and maintained their weight loss over a four-year period had significantly lower blood pressure at the end of the study than when they started the study. Another study found similar results after following overweight or obese subjects who lost a modest amount of weight over a three-year period.
Good information on the long-term benefits of weight loss for people with diabetes should be available in about five years. In 2001, a 12-year, randomized, clinical trial called “Look AHEAD: Action for Health in Diabetes” was started involving 5,000 people with Type 2 diabetes who were either overweight or obese at the beginning of the study. The goal is to have the people in the treatment group lose 7% to 10% of their body weight and maintain that weight loss throughout the study. The researchers will observe how long-term weight loss affects blood pressure, blood cholesterol and other lipids (fats in the blood), diabetes control, and the incidence of heart attacks and stroke.
Strategies for maintenance
Guidelines issued by the National Heart, Lung, and Blood Institute and the North American Association for Study of Obesity recommend a comprehensive program of diet, exercise, and behavior therapy for the management of obesity. All three of these components need to be sustained for a lifetime for weight loss to be permanent. So no matter what particular path you take to lose weight—and there are many programs out there, both commercial and noncommercial, to assist with weight loss—choosing a route that addresses all three will help you succeed at weight loss and increase your chances of keeping the weight off for the long term.
One source of information on weight loss that is being studied in a systematic way is the National Weight Control Registry, which is a voluntary registry of people who have lost at least 30 pounds of excess weight and kept it off for at least a year. People who enroll are periodically asked to complete questionnaires about their success at losing weight, current weight maintenance strategies, and other health-related behaviors. (To learn more about the registry or to join it, log on to www.nwcr.ws or call  606-NWCR .) The hope is that others can learn from those who have succeeded.
There are currently more than 5,000 people in the registry, which was started in 1994. The average participant has lost 60 pounds and has maintained that loss for five years. Approximately 50% of the people in the registry lost the weight on their own, without the help of an outside program. To maintain their weight loss, people in the registry continue to pay attention to diet and get an average of 60 minutes a day of physical activity, with walking being the most frequently reported form of exercise. Most registry members report improvements in their energy, mobility, mood, self-confidence, and physical health after losing weight.
As far as diet is concerned, those in the registry tend to follow a low-calorie, low-fat diet. In a survey of 355 women and 83 men published in 1998, the women in the registry reported consuming an average of 1,306 calories per day (24.3% calories from fat) and the men 1,685 calories per day (23.5% calories from fat). For an idea of what these calorie levels look like in actual food, see “Maintenance Meal Plans.”
A study of registry members published in 1999 examined why some people gain back weight they have lost. Factors making regain of lost weight likely included having lost weight more recently (less than 2 years before the survey), having lost a large amount of weight (more than 30% of maximum body weight), depression, and binge eating disorder. Those who regained weight reported getting less physical activity and eating a higher-fat diet than those who maintained their weight loss.