Losing weight is a common piece of lifestyle advice to help reduce the risk of chronic disease. The advice is easy to give but much harder to do.
Initial weight loss is comparatively easy compared to the more difficult part of maintaining it. Weight regain is the inevitable conclusion for most dieters. This sequence of weight loss and weight regain is called weight cycling or, more aptly, ‘yo-yo’ dieting.
Yo-yo dieting has been attracting greater scientific attention for the health problems it can cause. People with heart disease are frequently advised to lose weight so scientists have investigated whether weight cycling makes their condition better or worse.
Almost 10,000 people with heart disease were part of clinical study testing the effect of statin medications. Over four years, the people had regular assessments of their health and body weight.
People with the highest degree of body weight fluctuation were much more likely to suffer from heart disease, heart attack, stroke and other heart-related problems compared to people who had only small changes in weight. For every 1.5 to two kilograms in weight fluctuation, the risk of a cardiovascular event such as a heart attack or stroke went up by four percent. The risk of death went up by around nine percent.
For people with the highest degree of body weight variation, their risk of heart attack, stroke and death were all more than double compared to those who had a mostly stable weight. This much higher risk was still apparent after accounting for other factors that could explain the difference such as variances in age, sex, race, smoking, and the presence of other diseases.
Yo-yo dieting can be both a marker of poor health behaviours as well as an extra stressor placed on the body.
This new research cannot prove that weight cycling itself was the cause of the higher disease risk, but rather it may be a flag that such futile attempts should be discouraged in the first place in people who cannot maintain weight loss. Losing weight can still offer health benefits if it can be undertaken over the long-term, involving a committed overhaul of eating and activity.