Yo-yo dieting linked to heart trouble, risk of death

Repeated cycles of losing and regaining weight may do much more than cause wardrobe problems.

New research shows that the weight fluctuations that come with yo-yo dieting may be linked to a higher risk for stroke, heart attack, and death in people with pre-existing coronary artery disease.

The study, published in the New England Journal of Medicine, found that when compared to heart patients who kept their weight steady, those with the largest weight changes experienced:

• 136 percent more strokes
• 117 percent more heart attacks
• 124 percent more deaths

This is the first study to measure the effect of yo-yo dieting on health in patients with pre-existing heart disease.

“Back in the 90s there was a study done in patients with no heart disease, who were pretty healthy, that found that weight fluctuations over a decade actually increased the risk of death from heart disease,” Sripal Bangalore, M.D., director of the cardiovascular outcomes group at NYU Langone Medical Center, told CBS News. “So we wanted to see if — in patients who already have heart disease, where there is so much emphasis on weight loss — is this weight cycling harmful.”

For the study, Bangalore and his team reviewed data on more than 9,500 men and women between the ages of 35 and 75 with coronary artery disease, high cholesterol levels, and some history of heart problems. All patients were followed for about five years.

Individuals in the high-fluctuation group had weight changes as large 8.6 pounds, while weight varied by just under 2 pounds in the group with the smallest shifts.

Importantly, the study showed that the association between weight fluctuations and risk for stroke, heart attack, and death were only seen in patients who were overweight or obese at the beginning of the study. Statistically significant links were not seen in people who started with normal weight.

The study authors caution that their research does not prove a cause-and-effect relationship between yo-yo dieting and increased risk of health problems and death. It merely shows an association.

And while the study doesn’t look at potential reasons for the link, experts have some theories.

“What this study clearly demonstrates is something we have suspected for a long time, that gaining, losing and re-graining weight is stressful on the body,” Alice H. Lichtenstein, director of the Cardiovascular Nutrition Laboratory at Tufts University, told CBS News.

Bangalore notes that the study also patients with high weight fluctuations were more likely to develop diabetes, which could also explain an increased risk of other health problems and death.

He said he hopes the findings will provide motivation for patients to not only lose weight but to work to keep it off.

Experts believe updated clinical guidelines are needed to help patients achieve this.

“Losing weight is hard but there have been some successful programs,” Lichtenstein said. “Keeping the lost weight off is harder and we don’t have as many successful programs. Hence, more emphasis needs to be put on finding successful strategies for maintaining weight loss. It needs to be an integral part of weight loss programs, not an add on.”