Preference and detrimental effects of high fat, sugar, and salt diet in wild-caught Drosophila simulans are reversed by flight exercise

High saturated fat, sugar, and salt contents are a staple of a Western diet (WD), contributing to obesity, metabolic syndrome, and a plethora of other health risks. However, the combinatorial effects of these ingredients have not been fully evaluated. Here, using the wild-caught Drosophila simulans, we show that a diet enriched with saturated fat, sugar, and salt is more detrimental than each ingredient separately, resulting in a significantly decreased lifespan, locomotor activity, sleep, reproductive function, and mitochondrial function. These detrimental effects were more pronounced in female than in male flies. Adding regular flight exercise to flies on the WD markedly negated the adverse effects of a WD. At the molecular level, the WD significantly increased levels of triglycerides and caused mitochondrial dysfunction, while exercise counterbalanced these effects. Interestingly, fruit flies developed a preference for the WD after pre-exposure, which was averted by flight exercise. The results demonstrate that regular aerobic exercise can mitigate adverse dietary effects on fly mitochondrial function, physiology, and feeding behavior. Our data establish Drosophila simulans as a novel model of diet-exercise interaction that bears a strong similarity to the pathophysiology of obesity and eating disorders in humans.

Automated summary

A Western diet high in saturated fat, sugar, and salt has detrimental effects on Drosophila simulans, affecting lifespan, activity, sleep, reproduction, and mitochondrial function, with females being more affected than males. Regular aerobic exercise can counteract these negative effects and mitigate changes in triglyceride levels and mitochondrial dysfunction caused by the diet. Additionally, pre-exposure to the diet increased fruit flies' preference for it, which was prevented by flight exercise. This study establishes Drosophila simulans as a novel model for studying the interaction between diet and exercise, mirroring aspects of obesity and eating disorders in humans.