Energy needs of the body are measured in which units?

Energy needs of the body are measured in calories primarily because calories quantify the amount of energy that food provides when consumed. The body uses this energy to perform a variety of functions, including maintaining bodily processes at rest, physical activity, and digestion. One calorie is technically defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius.

In contrast, grams are a unit of mass and are used to measure the weight of food, but do not directly measure energy. Carbohydrates and nutrients refer to specific categories of food components and not to energy measurement. While carbohydrates provide energy—along with fats and proteins—they are a macronutrient rather than a unit of measurement. Thus, understanding that energy is quantified in calories helps in determining dietary needs and managing nutritional intake effectively.