Protein, carbohydrate and fat comprise the macronutrients and are referred to as the energy nutrients because upon burning in the lab or by the human body, heat is yielded (measured in calories). These nutrients provide us with calories to continue life processes, such as breathing, growth and maintenance, cardiac work, voluntary activity, and thousands of metabolic reactions.

Protein is always a concern in malnutrition both in terms of adequacy and quality. Protein quality is measured using the Protein Digestibility Corrected Amino Acid Score (PDCAAS) (Report of the Joint FAO/WHO Expert Consultation, 1991). This score takes into account the digestibility and therefore bioavailability of the protein and how the amount of essential amino acids contained in the protein compare to the amino acid requirements of children 2-5 years of age. It is a useful tool, because one can quickly see on a scale of 0 to 1.0 a protein's quality score and compare it to other protein sources.

All people require nutrients to sustain life and those with acute illnesses have increased requirements for specific nutrients. For example, persons with fever will burn more calories than people with normal temperatures. Any person with an illness is in a state of metabolic stress which results in increased nutrient requirements and therefore places him/her at risk for malnutrition. If malnutrition is not alleviated, the disease is further exacerbated which in turn further increases the degree of malnutrition.

People living with HIV/AIDS, a disease of the immune system, have increased nutrient requirements over their healthy counterparts. HIV/AIDS infects men, women, pregnant and lactating women, children and infants so nutrient requirements must be determined by gender, age and condition. Nevertheless, some general guidelines are suggested by Food and Nutrition Technical Assistance (FANTA).

Weight loss and wasting are characteristic of AIDS patients. These symptoms are a result of reduced food intake (appetite is impaired), poor absorption of nutrients, and changes in metabolic processes affecting protein synthesis. Additionally, some individuals experience diarrhea and nausea, further compounding the problems of maintaining body weight and nutrient stores. FANTA guidelines recommend 10-15 percent additional calories per day for adults with HIV/AIDS. For example, if 2070 kcal per day is used as the estimate for energy needs for an active non-HIV-infected adult, then the additional calories needed for HIV/AIDS patients (at the 15% level) are about 300 to 400 for women and men respectively. For protein, the additional recommended amount is 50 to 100 percent per day. This translates to approximately 72 grams of protein per day for women and about 85 grams per day for men. Amino acid supplementation is not recommended, but instead, foods such as rice, soybeans, nuts and grains are preferred for obtaining needed amino acids. Easy to digest foods with high quality protein are needed.

About 50 % or the total carbohydrate recommended for healthy adults and children should be complex carbohydrate. For people with HIV/AIDS, this percentage may need to be higher since fat should be restricted and these fat calories must be replaced by either carbohydrate or protein. Burning carbohydrate in the human body as a fuel rather than fat and protein requires less water. Reliance on fat and protein to meet energy needs results in frequent urination and increased requirements for water intake. Easily digestible foods, high in carbohydrates such as rice, bread, millet, maize porridge, potato, sweet potato and crackers are recommended. Further, if diarrhea exists, one of the remedies recommended is to consume rice soup (1 cup rice + 5 cups water and a bit of salt-the latter provides the electrolyte, sodium- boiled for one hour). FANTA states that this is a traditional medicine for diarrhea and is used because of its well-known efficacy, limited side effects, and ease of preparation. Amounts of the electrolytes, potassium and sodium, required to restore hydration vary according to age, gender, weight, and health status.

Micronutrients required specifically for building a strong immune system are needed in excess over those required for a non-HIV-infected adult. These include vitamins A, B6, iron and zinc as well as specific amino acids. Another issue to keep in mind is that certain medications may interact with specific nutrients and prevent either the nutrient or the drug from performing as intended. For example, vitamin B6 (10mg daily) supplementation is recommended for TB patients treated with isoniazid (FANTA). Further, when macronutrients are increased, specific micronutrients are needed to facilitate metabolism of the increased macronutrients. For example, an increase in dietary protein requires increased vitamin B6 for the metabolism of the extra protein. This latter point reemphasizes the importance of keeping in mind the interrelationships among nutrients when planning diets or food products.

FANTA points out that supplementation of the micronutrients, vitamin A and the B-group vitamins, (B6 and B12) have improved survival and reduced disease progression in people with HIV/AIDS. Children with HIV/AIDS need to be given supplements of both iron and vitamin A and should be encouraged to consume foods rich in vitamin C.