In the context of energy balance and weight change, approximately how many kilocalories (Calories) are stored in 1 pound (lb) of body fat?

• A. About 1,500 kilocalories (kcal)
• B. About 7,000 kilocalories (kcal)
• C. About 500 kilocalories (kcal)
• D. About 3,500 kilocalories (kcal)

Answer: (D)

Verified step by step guidance

1. Understand that body fat stores energy, and this energy is measured in kilocalories (kcal), which are commonly referred to as Calories in nutrition.
2. Recognize that when discussing weight change, the energy stored or expended is related to the amount of fat tissue gained or lost.
3. Recall the widely accepted estimate in nutrition science that 1 pound (lb) of body fat contains approximately 3,500 kilocalories (kcal) of stored energy.
4. This estimate is based on the fact that fat tissue is not 100% pure fat, but contains some water and other components, so the energy content is slightly less than pure fat, which has about 9 kcal per gram.
5. Therefore, the key takeaway is that to lose or gain 1 pound of body fat, there needs to be a deficit or surplus of about 3,500 kilocalories in energy balance.