Changes in weight and metabolic health during and after cessation of a time-restricted feeding plus aerobic training in Swiss mice fed a high-fat diet.

Obesity is a chronic disease, representing a significant health problem worldwide. Unhealthy eating habits and sedentarism are key contributors to the development of obesity. Dietary and exercise strategies are the first-line therapies for weight loss or maintenance and have proven effective in controlling weight. However, long-term adherence is challenging, and rapid weight regain often follows intervention cessation. In mice, time-restricted feeding (TRF) and exercise (EXE) independently prevent weight gain and maintain metabolic health, yet weight regain is observed upon cessation. Whether combining TRF and EXE provides longer-lasting benefits remains unclear. Here, we assessed weight and metabolic parameters in Swiss male mice fed with a high-fat diet (HFD) during an 8-wk intervention of TRF (8-h food access in the active phase) or TRF combined with EXE (60-min treadmill running daily) and after cessation and transfer to ad libitum feeding. TRF and EXE interventions successfully mitigate weight gain, improve glycemic homeostasis, and attenuate lipid accumulation in the liver and adipose tissue hypertrophy compared to mice fed HFD ad libitum. However, cessation of both strategies led to rapid weight regain, impaired glycemic control, and increased circulating lipid levels. Although the combination of TRF and EXE led to the lowest body weight and best metabolic health, this group showed no protection against the metabolic impairments observed after TRF cessation alone. In conclusion, TRF and EXE are complementary strategies for managing metabolic health, but cessation of these interventions leads to rapid weight regain and metabolic deterioration, with only partial preservation of select metabolic adaptations. These findings underscore the critical need for sustained adherence to lifestyle interventions in obesity management.NEW & NOTEWORTHY This study demonstrates that combining time-restricted feeding with aerobic training improves weight and metabolic health in Swiss mice fed a high-fat diet. Importantly, we show that most metabolic benefits are lost after intervention cessation. However, insulin sensitivity and aspects of hepatic lipid metabolism are partially maintained after cessation of the intervention. These findings provide new insight into the durability of metabolic improvements induced by lifestyle interventions and highlight the potential of combined dietary and exercise strategies to counteract diet-induced obesity and metabolic dysfunction.