New research suggests that cycles of intentional weight loss followed by regain was mot associated with an increased risk of developing cancer.

Researchers found that yo-yo dieting was not associated with overall risk of cancer in men or women after adjusting for body mass index and other factors. Weight cycling was also not associated with any individual cancer investigated.

"For the millions of Americans struggling to lose weight, the last thing they need to worry about is that if it comes back, they might raise their risk of cancer," Dr. Victoria Stevens, who led the study, said in a statement. "This study, to our knowledge the largest and most comprehensive to date on the issue, should be reassuring. Our findings suggest that overweight and obese individuals shouldn't let fears about their ability to maintain weight loss keep them from trying to lose weight in the first place."

Previous studies have suggested that weight cycling may affect biological processes that could lead to cancer, such as increased T-cell accumulation, enhanced inflammatory responses in adipose tissue, and lowered natural killer cell cytotoxicity. However, many of these findings have not been replicated, and at least two previous studies showed no associations between weight cycling and cancer.

For the latest study, researchers examined yo-yo dieting and 15 individual cancers among more than 132,000 men and women enrolled in the Cancer Prevention Study II Nutrition Cohort. Begun in 1992/1993, the Nutrition Cohort gathered detailed dietary information from men and women ages 50 to 74 participating in the Society's larger Cancer Prevention Study II, to explore nutrition's effect on and cancer incidence and mortality.

The findings are detailed in the American Journal of Epidemiology.