When we talk about food and how it fuels the body, several key terms come into play—each referring to a different aspect of nutrition and energy. A calorie is often used as a unit of measurement to indicate how much energy food provides. Nutrients are substances found in food that support body functions, including vitamins, minerals, proteins, fats, and carbohydrates. Macronutrients—such as carbs, proteins, and fats—are the major categories of nutrients that supply energy and build tissues. Metabolism refers to the body’s process of converting food into energy and managing that energy for essential functions like movement, repair, and temperature regulation. While these terms are often used together in health and fitness conversations, they each describe a different part of how the body processes what we eat. Understanding these concepts helps you make better food choices and manage your energy levels more effectively.