Vitamins and minerals are referred to as micronutrients because the body requires only small amounts. Foods can be classified as high or low nutrient density depending on the amount of nutrients and calories. High nutrient density refers to foods that contain few or moderate calories but are packed with nutrients. Foods that have a lot of calories but few nutrients are of low nutrient density are commonly called junk food or empty calories. Calorie is the unit of measure indicating the energy value of food and the cost of physical activity.
People commonly call it a calorie rather than kcal.
Carbohydrates n Carbohydrates constitute the major source of calories the body uses to provide energy for work, maintain cells, and generate heat. The major sources are breads, cereals, fruits, vegetables, and mild and other dairy products. Carbohydrates are classified as simple and complex. Glucose is a natural sugar found in food, but it also is produced in the body from other simple and complex carbohydrates. Glycogen is a long chain of glucose molecules hooked together.