Calorie intake refers to the amount of energy that is consumed by an individual through food and beverages. It is measured in calories, which is a unit of energy that represents the amount of heat required to raise the temperature of one gram of water by one degree Celsius. The body needs a certain number of calories each day to maintain its basic functions such as breathing, circulating blood and maintaining body temperature. However, the exact number of calories needed varies from person to person depending on factors like age, gender, weight, height, and level of physical activity. Consuming more calories than required can lead to weight gain while consuming fewer calories than required can result in weight loss. Therefore, monitoring one's calorie intake is an important aspect of maintaining a healthy body weight.