A calorie is a unit of measure used to measure the energy provided by food. A person’s energy requirements depend on their age, height, weight, gender and activity level. When a person consumes more calories than they burn off they store the excess as body fat (energy in reserve) in their fat cells which results in weight gain. When a person consumes less calories than they require as fuel they burn their fat stores which results in weight loss.
Calories come from protein, fat, carbohydrates and alcohol. Protein and carbohydrates provide about 4 calories per gram. Fat provides about 9 calories per gram. Alcohol provides about 7 calories per gram.
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