In food energy labeling, what is the correct distinction between a calorie (cal) and a Calorie (Cal)?

• A. A calorie (cal) is 1,000 kilocalories, while a Calorie (Cal) is 1 kilocalorie.
• B. A calorie (cal) and a Calorie (Cal) are identical units with no difference in magnitude.
• C. A calorie (cal) measures protein energy, while a Calorie (Cal) measures fat energy.
• D. A Calorie (Cal) is a kilocalorie and equals 1,000 calories (cal).

Answer: (D)

Verified step by step guidance

1. Understand that in nutrition, the term 'calorie' can refer to two different units: the small calorie (cal) and the large Calorie (Cal), also known as a kilocalorie.
2. Recognize that the small calorie (cal) is the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.
3. Know that the large Calorie (Cal), often used in food energy labeling, is equivalent to 1,000 small calories (cal), and is the amount of energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius.
4. Note that in dietary contexts, the Calorie (Cal) is synonymous with a kilocalorie (kcal), which is the standard unit used to express the energy content of foods.
5. Therefore, the correct distinction is that 1 Calorie (Cal) = 1 kilocalorie (kcal) = 1,000 calories (cal), and this is the unit typically used on food labels to indicate energy.