Why do bucks stop eating during rut?
Bucks don't fully stop eating during the rut, but mature bucks reduce feeding by 50–80% during peak breeding because seeking does and breeding outranks foraging on their priority list. They burn body fat instead — losing 20–30% of body weight by the end of November.
Testosterone-driven behavior overrides hunger. A mature buck patrolling for estrous does will pass food sources he would have hammered in early October. He'll snatch a few mouthfuls at a doe-feeding location while scent-checking but won't post up to feed.
This is why food-source stand sits collapse during peak rut for mature bucks — does are still feeding, younger bucks are feeding, but the deer you're hunting has shifted to travel corridors and pinch points. Switch your stand strategy off food sources and onto bedding-area edges and rub-scrape lines during the peak window. See your state's rut dates and current mast reports for context.