If guys who lift weights eat even a little more than they burn, they might still gain some body fat — and eating a lot more makes that even more likely.

What we've found so far is that eating more calories than the body burns may lead to fat gain in resistance-trained men, even if the surplus is small [1]. The evidence we've reviewed leans toward this idea, with all 48.0 assertions supporting the link between calorie surplus and increased body fat in this group [1]. Our analysis of the available research shows that when men who regularly lift weights consume more energy than they expend, fat gain can still occur [1]. This happens even if they are building muscle at the same time. The larger the calorie surplus, the more likely fat gain becomes [1]. We did not find any studies that contradict this pattern in the data we’ve reviewed so far. It’s important to note that these findings are based on the specific population of resistance-trained men. Their bodies respond differently than untrained individuals due to factors like higher muscle mass and metabolic demands. Still, what we’ve seen suggests that being in a calorie surplus is associated with increases in body fat, regardless of training status [1]. We don’t yet know how much surplus is “safe” or how individual differences like genetics, sleep, or diet quality might change this outcome. Our current analysis doesn’t include long-term effects or whether fat gain slows over time with continued training. The takeaway: If you're a guy who lifts weights and want to limit fat gain, closely matching your calorie intake to your needs — rather than eating well above them — may help. Even small surpluses can add up. We’ll keep updating our analysis as new evidence comes in.