A calorie surplus is when you consume more calories than your body needs for energy. This can be used to either gain weight or build muscle mass, depending on the individual’s goals. It involves eating more calories than the amount of energy that is burned off in a given day. The extra calories are stored as fat or turned into muscle depending on the type of exercise and physical activity. Eating a calorie surplus is particularly useful for athletes or those looking to either build muscle mass or increase their bodyweight. It can also be used as part of weight loss strategies when combined with increased physical activity.