Restricting eating hours led to lasting fat loss in flies

In Drosophila fruit flies, researchers tested intermittent time-restricted feeding, which limits the hours when food is available. They compared ten days on this schedule with unrestricted access to food. The restricted schedule reduced stored fat, and the effect persisted after the flies returned to unrestricted feeding. It also reduced obesity caused by diet or genetic changes and shrank fat-storage droplets in the flies’ fat tissue.

The flies had higher total and muscle-specific protein levels and better flight performance, suggesting a shift in body composition. Fasting also prompted increased activity, partly mediated by octopamine, the fly counterpart of the human stress hormone norepinephrine. Removing nerve cells that produce octopamine prevented the fat loss, protein increase and flight improvement. The researchers suggested that a “fight or flight” response underlay these effects.