A calorie is a unit of energy that your body uses to perform its numerous functions. The three nutrients in the food you eat, which provide your body with energy – or calories – are carbohydrates, protein and fat.
Eat approximately 1500 calories (for men) and 1000 calories(for women) each day from a combination of these three nutrients.
Four calories are in each gram of carbohydrates. Carbohydrates are your body’s preferred energy source, as they provide immediate fuel for daily functions and exercise. The recommended caloric intake from carbohydrates is 45 to 65 percent of your total daily calories.
Each gram of protein has four calories. Protein helps build and sustain your body’s tissue. The recommended caloric intake from protein is 10 to 35 percent of your total daily calories.
Nine calories are in each gram of fat. Fat assists your body in transporting and absorbing vitamins and minerals. The recommended caloric intake from fat is 20 to 35 percent of your total daily calories.
Seven calories are in each gram of alcohol. Alcohol is not a nutrient like carbohydrates, protein and fat, but alcohol does supply the body with calories.