Time-restricted eating promotes sustained fat loss in Drosophila

Time-Restricted Eating (TRE) has been found to promote significant fat loss and muscle preservation in Drosophila, according to new research. Unlike other calorie-restriction methods, TRE involves restricting the time window for eating and has already shown promise in preventing obesity in mice and humans. In this study, Drosophila were subjected to 10 days of intermittent Time-Restricted Feeding (iTRF) and showed substantial fat loss compared to those on an unrestricted diet. This fat loss effect was maintained even after returning to unrestricted feeding.

The research found that iTRF-induced fat loss did not rely on circadian-regulated autophagy, unlike lifespan extension observed with iTRF. Moreover, iTRF effectively treated and prevented diet-induced and genetic obesity, reducing lipid droplet size in the fat body. Unlike other treatments, iTRF did not result in muscle loss; instead, it increased overall and muscle-specific protein levels and enhanced flight performance, indicating an improvement in body composition.

Interestingly, iTRF triggered a "fight or flight" response through the activation of octopamine, the fly counterpart of the human stress hormone norepinephrine. Fasting-induced hyperactivity, a form of timed exercise, did not lead to fat loss on its own. However, the absence of octopaminergic neurons (OANs) prevented iTRF-mediated fat loss, protein gain, and improved flight performance. OCTOPAMINE was both necessary and sufficient for iTRF-mediated fat loss.

In summary, this study suggests that intermittent fasting in Drosophila induces rapid, permanent fat loss by activating a "fight or flight" response while simultaneously enhancing muscle function. Further exploration of this mechanism could provide valuable insights into therapeutic interventions for obesity in humans.