A low protein diet drives short and long-term improvements in metabolic health in a mouse model of sleeve gastrectomy

Despite the largely beneficial impact of bariatric surgery on obesity and metabolic disease, many patients continue to suffer from obesity after surgery and weight recurrence is common. The success of bariatric surgery may be impacted by diet. While bariatric surgery guidelines recommend a high-protein diet following surgery based on the theory that this will preserve lean mass, emerging evidence suggests that both humans and mice are metabolically healthier when consuming low protein diets. Here, we assess the effect of varying dietary protein levels on post-surgical weight loss and weight regain in a mouse model of bariatric surgery, sleeve gastrectomy. We find that a low protein diet optimally drives post-surgical weight loss, boosting energy expenditure and improving blood glucose regulation. Using a multi-omics approach, we identified clusters of differentially expressed genes and metabolites that correlated with these phenotypes and find that diet heavily influences the molecular response of the liver to sleeve gastrectomy. These results suggest that current post-surgical dietary guidelines recommending a high protein diet may limit both the short and long-term benefits of surgery and lead us to conclude that a low protein diet may improve patient outcomes.