Knowledge about the relationship between the human immunodeficiency virus (HIV), nutritional status, treatment, food and nutrition interventions continues to accumulate. This article provides an overview of the main nutrition related issues for people living with HIV (PLHIV) and a review of the potential benefits of nutrition interventions for people affected by HIV. Nutrition plays a vital role in the immune system of all people, including (PLHIV). Good nutrition strengthens the immune system, while HIV infection and poor nutrition have a cumulative effect in damaging it. PLHIV are more vulnerable to malnutrition than the general population and nutritional status is a good predictor of their mortality risk. Malnutrition in PLHIV often occurs in a background of poverty and lack of access to food. It is not always possible to identify one single cause as the main contributor to declining nutritional status or malnutrition in HIV. Inadequate food intake, increased requirements and malabsorption are the main reasons for weight loss in PLHIV. Asymptomatic adults with HIV infection have a 10% higher energy requirement and symptomatic PLHIV have 20-30% higher energy requirements than the general population. Kilojoule/kilocalorie requirements increase by 50-100% in children experiencing weight loss. Evidence for increasing protein and micronutrient intake in healthy PLHIV is inadequate. Nutritional education should be an essential component of HIV care and treatment, as it can help PLHIV cope with symptoms of disease, prevent weight loss and manage side effects of medication. In resource limited settings, food support programs may be required in addition to nutrition support to optimise nutritional status and health outcomes in PLHIV who are food insecure.