Questions: Calories and Energy

Question 1

Fat provides 9 calories per gram while carbohydrates provide 4 calories per gram. If you eat 10 grams of fat and 10 grams of carbohydrates, how many total calories have you consumed?

• A. 40 calories
• B. 90 calories
• C. 130 calories
• D. 140 calories

Answer: (C)

10 grams of fat × 9 cal/g = 90 calories from fat. 10 grams of carbohydrates × 4 cal/g = 40 calories from carbs. Total: 90 + 40 = 130 calories. This shows why fatty foods are more calorie-dense -- gram for gram, fat contains more than twice the energy of carbohydrates or protein.

Question 2

You mainly burn calories when you are exercising or physically active.

• T. True
• F. False

Answer: False

Your body burns calories 24 hours a day, even while sleeping. Your heart needs energy to beat, your lungs need energy to breathe, your brain needs energy to think, and your cells need energy to maintain and repair themselves. In fact, most of the calories you burn each day (roughly 60-75%) go toward these basic life-sustaining functions, called your basal metabolic rate. Exercise adds to this baseline, but it's not the only time your body uses energy.

Question 3

If calories are just a unit of energy, why does it matter whether your calories come from vegetables or candy?

Model answer: While both provide the same amount of energy per calorie, vegetables also provide vitamins, minerals, and fiber that candy does not. Vegetables also tend to fill you up more because of their water and fiber content, making it harder to overeat. Candy provides energy but little else nutritionally, and it's easy to consume large amounts quickly.

This is the difference between calorie quantity and nutritional quality. A calorie is a calorie in terms of energy, but the food delivering those calories matters enormously. Nutrient-dense foods (vegetables, whole grains, lean proteins) give you energy plus vitamins, minerals, and fiber. Nutrient-poor foods (candy, soda) give you energy with little else. This concept is called nutrient density.