Malnutrition, weight loss, and chronic diarrhea are common findings in patients infected with human immunodeficiency virus (HIV), and many traditional and nontraditional dietary approaches have been suggested. This article examines the mechanisms and pathophysiology of wasting in HIV, and the evidence for malnutrition of protein, energy, and micronutrients in patients with the acquired immunodeficiency syndrome (AIDS). The article concludes with a review of dietary therapy in AIDS patients.