What Is a Calorie and Why It Matters

A calorie is a unit of energy that tells us how much energy food provides to the body. Your body uses this energy to perform all vital functions, such as breathing, thinking, moving, and maintaining body temperature. Simply put, calories are the fuel that keeps your body working every day.

The number of calories you consume affects your weight and overall health. Eating more calories than your body needs can lead to weight gain, while consuming fewer calories may result in weight loss. However, calories are not the only factor—food quality also plays a major role.

Not all calories are equal in terms of nutrition. Foods rich in protein, fiber, vitamins, and minerals support better health than foods high in sugar and empty calories. Understanding what calories are and why they matter helps you make smarter food choices and build healthier eating habits for the long term.