According to the food and nutrition board (fnb) of the national academy of sciences, 45% to 65% of calories should come from carbohydrates.
The diet should contain all the necessary components of diet in proper amounts. The processes of human physiology require chemical energy which is supplied by proteins, carbohydrates, lipids, vitamins and minerals. The main source of calcium is found in the dairy products. Carbohydrates can be found in a variety of foods such as grains, legumes, nuts, fruits, milk, vegetables, yogurt, and seeds.
Adults should obtain 45% to 65% of the calorie requirement from carbohydrates, 20% to 35% from fats and 10 to 35% from the proteins. The acceptable range for children are similar to the adults except that infants and younger children need a little higher amount of fat around 25 -40 %.
