If total food calories exceed daily energy expenditure, excess calories accumulate as fat in adipose tissue
Explanation:
Calories is the measurement of energy released when the food is digested.
Proteins, carbohydrates and fats get digested to release energy.
Proteins and carbohydrates yield approximately equal amount of energy on getting digested. While fats yield maximum amount of energy.
If the amount calories produced by digestion of food exceeds the total amount of calories used up then the excess calories are stored as fats in the adipose tissue of the body.
This is the major reason why overeating and decreased physical activities results in obesity.