Losing weight is easy. Just ask Oprah Winfrey, or the millions of other dieters who are on a weight-loss roller coaster. They manage to lose five, 20, or 50 pounds -- only to gain it all back. Doctors call this "weight cycling," but it's better known as yo-yo dieting.
Yo-yo dieting can be extremely frustrating. Studies suggest that repeated cycles of weight loss and weight gain may also be harmful to your health, but no study has definitively proven that. If you've ever tried to lose weight or plan to diet in the future, you should know the ins and outs -- or rather the ups and downs -- of the yo-yo diet.
Why does lost weight come back?
Many people look for quick fixes to their weight problem. They starve themselves or go on a fad diet and rejoice as the pounds disappear. But as soon as they return to their old habits, the weight comes right back. Even dieters who take the slow-and-steady approach to weight loss can sometimes go back to square one. Simply put, permanent weight loss requires a lifelong commitment taking in no more calories than you can use -- a goal that's often reached by exercise. Anyone who wants to lose weight but can't make that commitment is bound to end up on the yo-yo.
As you age, another factor comes into play: Weight can build up or quickly return because your metabolism slows down, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Studies show, however, that this weight gain is preventable: So if you're eating the same way in your 40s as you did when you were 20, you probably just need to cut back calories or increase your activity.
What are the health risks of yo-yo dieting?
No matter what your size, any sudden weight gain or loss may be hard on your health. A study of 485 female heart patients published in the Journal of the American College of Cardiology found that yo-yo dieters had relatively low levels of HDL cholesterol -- the "good" cholesterol that helps prevent heart disease. The shortfall of HDL was especially severe in women who had lost and regained at least 50 pounds. However, researchers found no direct link between low HDL and heart disease in any of the women. Other studies have found that yo-yo diets may slightly boost a person's blood pressure (although it's unknown whether the higher level is only temporary). Fluctuations in weight also seem to increase the risk of gallstones.
Of course, these risks have to be put into perspective. A yo-yo diet may shake up your system, but it's not thought to be as unhealthy as obesity itself. Extra pounds can make you a target for heart disease, stroke, diabetes, cancer, orthopedic problems, and other ailments. For those who are carrying extra pounds, even a modest reduction in weight can greatly improve overall health.
If you're overweight, you shouldn't let the specter of yo-yo diets keep you from trying to lose weight. Instead, you should feel extra resolve to keep weight off once you lose it. If you're already at a healthy weight, try to keep it steady.
Can yo-yo dieting change my body type?
Contrary to common belief, yo-yo dieting doesn't make a person fatter. In fact, people who go through a complete weight-loss cycle tend to end up with the same proportion of fat and muscle they started with. If you work out during your cycle, you may actually be more muscular than you were before.
Does yo-yo dieting make it harder to lose weight in the future?
Many people fear that yo-yo dieting will slow down their metabolism and scuttle future attempts to lose weight. You should be concerned if you go on repeated starvation diets (less than 1,000 calories a day). You'll probably lose weight and muscle temporarily. But if you start to eat the way you did previously, your body may react by storing the fat faster and more efficiently, and you could add more pounds than before, according to the Mayo Clinic. Also keep in mind that controlling weight can be more challenging as you grow older because of hormonal changes that tend to encourage weight gain and perhaps changes in body composition.
If you have a history of yo-yo dieting, it's time to rethink your approach to weight loss. Remember: Permanent changes in your weight require permanent changes in your life. By getting plenty of exercise and eating only the number of calories you need to maintain or lose weight, you can reach a healthy weight -- and there won't be a string to pull you back.
National Institutes of Health. Weight Control Information Network. Weight Cycling.
Olson, M.B. et al. Weight cycling and high-density lipoprotein cholesterol in women: Evidence of an adverse effect. Journal of the American College of Cardiology. November 1, 2000. 36(5):1565-1571.
National Task Force on the Prevention and Treatment of Obesity. Weight cycling. Journal of the American Medical Association. Vol. 272(15):1196-1202.
The Hazards of Yo Yo Dieting, Mayo Clinic, http://www.mayoclinic.com/hlp/invoke.cfm?objectid=47C36183-C8B3-4906-924441E357EE1E18