Yoyo dieting disrupts gut health and drives weight regain and inflammation
A review from Deakin University, Australia, published in Nutrients, reveals the profound effects of yoyo dieting (cycles of weight loss and regain) on gut health. The review highlights how weight cycling leads to gut inflammation, changes in microbiota, and adaptations in the sympathetic nervous system (SNS), which together drive weight regain.
Background
Obesity now affects over half of the global adult population and is linked to millions of deaths from diseases such as cardiovascular disease and type 2 diabetes. One of the major challenges in managing obesity is sustaining weight loss. Studies show that most people regain lost weight within five years, a phenomenon known as yoyo dieting or weight cycling.
This weight cycling not only increases the risk of obesity-related conditions but also disrupts gut health. The review points to emerging evidence that weight regain alters gut microbiota, with adaptive metabolic responses further complicating long-term weight management.
Gut Hormones and Energy Balance
Energy balance—the balance between intake and expenditure—is regulated by signals from the gut, pancreas, and adipose tissue. Many of these signals come in the form of peptide hormones that either promote satiety or stimulate hunger. After weight loss, individuals often experience lower levels of satiety hormones (PYY, GLP-1, and CCK) and higher levels of hunger hormones like ghrelin. This hormonal imbalance makes maintaining weight loss difficult, driving overeating and weight regain.
The review also discusses how weight loss can reduce enteroendocrine cells (EECs), which produce these key hormones, further impairing the body’s ability to regulate hunger and satiety.
The Role of the Gut Microbiota
The gut microbiota, which plays a critical role in energy regulation, also undergoes changes during and after weight loss. Beneficial bacteria that produce short-chain fatty acids (SCFAs), such as Christensenella and Lactobacillus reuteri, often decline during yoyo dieting, impairing satiety and promoting weight regain. Conversely, weight regain is associated with an increase in pro-inflammatory bacteria, such as Desulfovibrio and Ruminococcus, which contribute to metabolic disorders and gut inflammation.
Yoyo Dieting and Inflammation
Yoyo dieting exacerbates obesity-related chronic inflammation. Studies show that weight regain triggers inflammatory responses in the gut, marked by elevated levels of inflammatory markers such as TNF-α and IL-6. This inflammation can compromise gut barrier function, worsening metabolic health.
Improving Gut Health After Weight Loss
While yoyo dieting is associated with negative changes in the gut, weight loss has been shown to improve gut health by reducing inflammation and promoting the growth of beneficial bacteria like Akkermansia and Bifidobacterium. However, research indicates that the gut microbiota may take considerable time to return to a healthier state, leaving individuals vulnerable to weight regain during this period.
Research Gaps and Conclusions
Though animal studies have highlighted important links between yoyo dieting and gut health, more human studies are needed to fully understand how weight cycling affects the gut microbiota and weight regain. The review concludes that while weight loss can improve gut health, the molecular mechanisms behind these changes are still unclear, and more research is needed to develop effective strategies for preventing weight regain.
In conclusion, yoyo dieting disrupts gut health, leading to hormonal imbalances, inflammation, and microbiota changes that drive weight regain. Addressing these factors could be key to improving long-term weight maintenance and reducing obesity-related health risks.
