Researchers at Colorado State University recently completed a review of the limited amount of science around yo-yo dieting (scientists call it weight cycling) and cancer risk. What’s interesting is that, although consistent caloric restriction has been shown to reduce cancer risk, it appears that yo-yo dieting might increase risk of certain cancers.
Weight Cycling and Cancer: Weighing the Evidence of Intermittent Caloric Restriction and Cancer Risk.
Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adverse effects of weight cycling on energy metabolism remain largely unsubstantiated, there also is a lack of epidemiological evidence that intentional weight loss followed by regain of weight affects chronic-disease risk. In the limited studies of weight cycling and cancer, no independent effect on post-menopausal breast cancer but a modest enhancement of risk for renal cell carcinoma, endometrial cancer, and non-Hodgkin’s lymphoma have been reported. An effect of either intermittent caloric restriction or fasting in protecting against cancer is not supported by the majority of rodent carcinogenesis experiments. Collectively, the data argue against weight cycling and indicate that the objective of energy balance-based approaches to reduce cancer risk should be to strive to prevent adult weight gain and maintain body weight within the normal range defined by body mass index.
Previous research has shown a relationship between yo-yo dieting and morbidity and mortality, although the underlying causes are not known. It’s also shown that the prevalence of yo-yo dieting is high.
Of course, adherents to the calorie counting paradigm will, as they always do, blame dieters for their diet’s failure. They will claim that this is caused by a “lack of willpower,” but now they rely on flawed, Oprah-inspired pop psychology to explain it. “You’re too stressed,” “You had a miserable childhood,” “Your life sucks, boo hoo,” etc. They won’t consider the well-established causes of their unsustainable, grain-based diet’s failure. Instead, they’ll look far and wide for vague, untestable answers in order to abstain from a much needed critical look at their own flawed nutritional theory.
In another recent study of dieters 63% of study participants engaged in yo-yo dieting. If most dieters fall prey to yo-yo dieting, can’t we conclude that a standard calorie restricted diet is more likely to wreck your health, give you cancer, or kill you, then help you? When will the medical establishment stop blaming its patients and wake up to this?
There is a better way.
1. Thompson HJ, McTiernan A. Weight Cycling and Cancer: Weighing the Evidence of Intermittent Caloric Restriction and Cancer Risk. Cancer Prev Res (Phila). 2011 Oct 7. [Epub ahead of print] PubMed PMID: 21982873.
2. Brownell KD, Rodin J. Medical, metabolic, and psychological effects of weight cycling. Arch Intern Med. 1994 Jun 27;154(12):1325-30. Review. PubMed PMID: 8002684.
3. Osborn RL, Forys KL, Psota TL, Sbrocco T. Yo-yo dieting in African American women: weight cycling and health. Ethn Dis. 2011 Summer;21(3):274-80. PubMed PMID: 21942158.