Post-dieting weight gain: The role of persistent microbiome changes

The prevalence of obesity is globally increasing and is associated with a reduction in life expectancy and quality of life worldwide [1]. Obesity confers a major risk factor for the development of metabolic syndrome, consisting of co-occurring pathologies such as Type 2 diabetes, cardiovascular diseases and nonalcoholic fatty liver. Dieting is one of the major approaches to target obesity. Even a modest reduction in weight can ameliorate Type 2 diabetes, hypertension and the risk for development of cardiovascular diseases [2]. Nonetheless, many dietary approaches fail due to difficulties in long-term post-dieting weight maintenance, caused by rapid weight regain that initiates repeated cycles of weight loss and regain (typically referred to as ‘yo-yo’ dieting). Weight cycling has been suggested to have detrimental effects on energy homeostasis and other metabolic pathologies [3], but the mechanisms initially driving this phenomenon remain to be fully elucidated [4]. Weight gain after intentional weight loss was found to be independent of genetic background [5], suggesting that behavioral and environmental factors are critical in mediating the frequent failure to maintain a reduced weight over time.