Yo-yo dieting healthier than obesity, indicates Ohio University study

Mechele R. Dillard's picture

Lack of permanent weight-loss results should not be a reason for not trying, according to a new study from researchers at Ohio University.

For years, dieters have been warned that yo-yo dieting is more dangerous to their health than remaining at an unhealthy weight. However, new data from an Ohio University study indicates that yo-yo dieters may actually live longer than those individuals who remain obese.

The new information on the effects of yo-yo dieting on one’s health were presented at the annual meeting of the Endocrine Society in Boston on Monday of this week. According to study results, mice who were made to “yo-yo diet,” switching between a high-fat and low-fat diet every four weeks over an approximate two-year lifespan, lived approximately 25 percent longer than the mice that were fed a consistently high-fat diet. The yo-yoing mice also had better blood glucose levels than their obese counterparts. As a control, another group of mice was fed a consistently low-fat diet; the yo-yo group lived almost as long as the control group mice, the study indicated. Overall, the lifespan of the mice was 2.04 years for the yo-yo mice; 1.5 years for the obese mice; and 2.09 years for the control mice.

The study followed 30 mice over their approximate two-year life spans. The mice that were fed a consistently high-fat diet ate more, weighed more and had higher levels of body fat, as well as higher fasting blood glucose levels. Additionally, the scientists reported that the mice became glucose intolerant, or pre-diabetic.

“If the conventional wisdom is true, it would discourage a lot of overweight people from losing weight,” said study lead author Edward List, a scientist at Ohio University’s Edison Biotechnology Institute. “The new research shows that the simple act of gaining and losing weight does not seem detrimental to lifespan.”

In fact, according to the study, although the health of the mice declined when they were on a high-fat phases of their diet, their health improved as they returned to the low-fat phases, with weight and blood glucose levels returning to normal.

List did acknowledge that it would be difficult to replicate his research in humans, as various factors, such as illness, can affect results. However, List indicated, the mice are a good model for humans in this instance, as researchers are able to follow the effects of a lifespan of diet differences over a relatively short period of time.

“Based on our results in mice, it appears that yoyo dieting has a much better effect on long term health and lifespan than remaining obese,” Dr. List said when he presented the study findings to the group at the Endocrine Society on Monday. “Furthermore, while several health parameters were negatively impacted during the HF cycle of the yoyo diet, little if any negative effect on longevity was observed. While remaining on a stable healthy diet provides the best outcome for health and longevity, it appears that it is much better to attempt to lose weight even in the face of repeated failures and fluctuating weight than to remain obese.”

Approximately 34 percent of American adults are classified as “obese,” and another 34 percent “overweight,” indicates the Centers for Disease Control and Prevention.

“The study adds to our understanding of the benefit of losing weight,” List said. “I would hope that this encourages people to not give up.”

Dr. List’s research is supported by the National Institutes of Health, AMVETS and Ohio University.

Image: Courtesy Ohio University

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