The quantity of calories used by your body to perform these essential tasks is known as your basal metabolic rate, often known as metabolism. Your particular basal metabolism is determined by a number of factors, including: your age; the amount of muscle tissue in your body; whether you are male or female; and the like. All living things must consume food to survive. The human body is no different - it needs nutrients to work properly and avoid illness. Food is the source of energy for our bodies and also provides the materials necessary for cellular maintenance. Nutritionists estimate that we need about 2000 calories per day to stay healthy. However, most people require more than this minimum amount. When you eat more calories than you use, some of them will be stored as fat. Calories are the unit used to measure the amount of energy contained in foods. All animals, plants, and humans need fuel to live their lives successfully. The two main types of fuels used by body cells are carbohydrates and proteins. These fuels are converted into energy that our bodies can use later when we need it. Carbohydrates are found in fruits, vegetables, grains, and beans. They provide the major source of energy for our bodies and brains.