In fruit flies subjected to repetitive mild traumatic brain injury, two intermittent fasting regimens produced longer lifespans, lower mortality and better behavioral performance than standard feeding. Benefits appeared in young (10-day) and middle-aged (21-day) adults, whether fasting began before or after injury. Expression analysis showed fasting significantly lowered antimicrobial peptides (AMPs), the fly's innate-immune inflammatory markers, in neural tissue from injured animals, pointing toward reduced secondary neuronal damage. This evidence comes from flies, not humans. Intermittent fasting already has a deep animal literature for lifespan and neuroprotection, so the novelty here is the injury context: repetitive mild head trauma, the pattern seen in contact sports and military service, which is linked to progressive neurodegeneration. The inflammation angle is plausible, since chronic neuroinflammation drives secondary damage after impact, and fasting is known to dampen innate immune signaling. Still, the leap to people is large. Fly brains, fasting schedules and injury mechanics differ greatly from human ones, and no human trial has tested whether fasting protects against the long-term consequences of concussion. Dietary restriction also extends fly lifespan in uninjured animals, so the study needs to show the benefit is specific to trauma rather than a general longevity effect. This is a preprint that has not been peer reviewed, so the findings may change. As an incremental, hypothesis-generating result, it justifies mammalian follow-up but offers no basis for changing eating habits after head injury; anyone with concussion history should discuss fasting with a physician.