In many developing countries, on the other hand, the major challenge is to meet daily energy need, and carbohydrate foods are usually the main source of energy. This is because humans use different nutrients selectively for their daily energy needs. The body has a limited capability to store protein and carbohydrate, none to store alcohol, and a virtually unlimited capacity to store fat. Calories from alcohol are used first, because conversion of alcohol to fat is energetically expensive.
Proteins are next to be used up, followed by carbohydrates.
Calories from fat are the last to be used to cover the remaining energy needs, and once that has been met, the excess is stored in the body's fat deposits. This is one of the reasons why eating high carbohydrate diets is likely to reduce the risk of obesity in the long term. The consumption of nuts, pulses and seeds should also be encouraged. Even if they represent only a relatively small amount of carbohydrate energy, they are a good source of protein and micronutrients, and their protein quality can be optimized when consumed with cereals. Studies have indicated that this diet may also be protective against colorectal cancer.