You probably don’t need a 300–500 calorie surplus to build muscle. A new 2026 preprint tried to estimate the actual energetic cost of constructing 1 kg of human skeletal muscle. Their estimate? About 3,481 kcal total. Spread across 12 weeks, that’s roughly 41 kcal/day. Basically… a rice cake. Now, don’t misunderstand this. That doesn’t mean adding 41 calories magically builds muscle. The calculation estimates the cost of constructing the tissue itself. It doesn’t fully account for training, recovery, remodeling, changes in activity, or individual differences. But it does challenge one of bodybuilding’s longest-running assumptions: You have to eat hundreds of calories above maintenance every day to maximize muscle growth. The limited research we have on intentional bulking points in the same direction: larger surpluses reliably produce more weight gain, but much of that additional weight tends to be fat—not extra muscle. Muscle growth is rate-limited. You can’t force-feed hy...