August 9, 2013

‘Yo-yo dieting’ inflames fat tissue

Gaining and losing weight during “yo-yo dieting” may contribute to an exaggerated immune response in fat tissue that increases metabolic dysfunction more than steady weight gain alone.


The cycles of weight loss and gain that accompany “yo-yo dieting” increase the risk of developing type 2 diabetes and cardiovascular disease. How weight cycling increases metabolic dysfunction – more than steady weight gain alone – is unknown.

Emily Anderson, Ph.D., Alyssa Hasty, Ph.D., and colleagues studied mice that were cycled between high and low fat diets to determine if weight cycling alters adipose (fat) tissue immune cell accumulation, inflammation and insulin resistance – factors that are known to contribute to the development of obesity-related disorders.

They report in the journal Diabetes that weight-cycled mice had decreased systemic glucose tolerance and impaired adipose tissue insulin sensitivity compared to mice that gained weight but did not cycle. Weight cycling increased the numbers of certain T cells and the expression of pro-inflammatory factors in adipose tissue.

The studies suggest that an exaggerated immune response in adipose tissue may contribute to metabolic dysfunction during weight cycling. This immune response may offer a therapeutic target for preventing obesity-related disorders.

This research was supported by a grant from the National Institutes of Health (HL089466). Hasty was also supported by an American Diabetes Association Career Development Award and an American Heart Association Established Investigator Award.