What daily calorie surplus is commonly suggested for adults aiming for gradual weight gain?

An addition of approximately 300 to 500 extra calories daily

For adults intending to increase their weight slowly and safely, the generally recommended approach involves establishing a consistent energy surplus. This surplus is specifically quantified as consuming between 300 and 500 calories more than the body expends on a daily basis. This moderate surplus allows the body the necessary resources to build new tissue, primarily lean mass and healthy fats, without drastically overloading the system, which could otherwise lead to excessive fat storage or digestive distress. Creating this consistent, controlled surplus is the fundamental requirement for any form of weight gain, as dictated by the laws of energy balance.