What is the unit for measuring the energy value of food?

The energy value of food is commonly measured in calories. A calorie is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. This unit is specifically used in the context of nutrition to quantify the energy provided by carbohydrates, proteins, and fats when consumed.

While kilojoules are also a valid unit for measuring energy (as one kilojoule equals approximately 239 calories), the calorie is the more traditional and widely recognized unit in the field of nutrition and food energy content. Joules, being a broader metric unit for energy, can measure various kinds of energy but are less commonly used in dietary contexts compared to calories. Grams measure mass, not energy, which is why this option does not relate to the energy value of food specifically.

Therefore, the calorie serves as the standard unit for expressing the energy content of food, making it the most relevant choice in this context.