Yo-Yo Dieting Not Linked to Cancer

Researchers at the American Cancer Society have found that weight cycling, also known as yo-yo dieting, is not likely to increase the risk of getting cancer. They say people who want to lose weight should try to do so, even though they may gain it back. “Everybody thinks yo-yo dieting is bad, but there really isn’t strong scientific evidence to suggest that,” said Victoria Stevens, PhD, the study’s lead researcher and American Cancer Society Strategic Director, Laboratory Services.

Stevens and her colleagues conducted the first large, comprehensive study to look at weight cycling and cancer risk. They analyzed 17 years’ worth of data from more than 132,000 people enrolled in the Cancer Prevention Study II Nutrition Cohort. The researchers defined weight cycling as losing 10 or more pounds on purpose, and then gaining it back. They concluded that yo-yo dieting was not linked to overall risk of cancer in men or women. It was also not linked to any of the individual cancer types they looked at, including cancers of the prostate, colon and rectum, pancreas, kidney, esophagus, liver, lung, and stomach, non-Hodgkin lymphoma, multiple myeloma, and melanoma skin cancer.

The study was published early online July 23, 2015 in the American Journal of Epidemiology.

Weight and cancer risk

Being overweight or obese is a known risk factor for some cancers, and Stevens says people who are overweight are more likely to try to lose weight, and therefore more likely to experience weight cycling. She says that even though the increased weight contributes to the risk, the cycling itself doesn’t. She says people should not be afraid to try to lose weight because if they can maintain the weight loss they can reduce their cancer risk, and even if they’re unsuccessful, there is no danger of raising cancer risk.

Stevens also says other myths about yo-yo dieting are also untrue. She says yo-yo dieting does not make it harder for people to lose weight, and it does not replace lean body mass with fat. Still, she recommends that people trying to lose weight make lifestyle changes they can stick to in order to keep the weight off. “Losing weight and maintenance of weight loss are two different things,” said Stevens. “Maintaining weight loss requires regular, long-term change, not just a quick fix.”

The American Cancer Society recommends:

  • Choosing foods and drinks in amounts that help you get to and maintain a healthy weight.
  • Eating at least 2½ cups of vegetables and fruits each day
  • Eating less red meat (beef, pork, and lamb) and less processed meat (bacon, sausage, luncheon meats, and hot dogs)
  • Choosing breads, pastas, and cereals made from whole grains instead of refined grains, and brown rice instead of white
  • Eating fewer sweets

In addition, adults should get at least 150 minutes of moderate-intensity activity (equal to a brisk walk) or 75 minutes of vigorous activity (makes your heartbeat and breathing faster, and makes you sweat) each week, preferably spread throughout the week.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Weight Cycling and Cancer Incidence in a Large Prospective US Cohort. Published early online July 23, 2015 in American Journal of Epidemiology. First author Victoria L. Stevens, PhD, American Cancer Society, Atlanta, Ga.

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