One of the major clinical manifestations of the acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) is the development of cachexia. This most likely results from a multifactorial interplay of poor diet, malabsorption, and altered metabolism. To assess the potential role of nutrient intake in the development or persistence of malnutrition, a detailed analysis was performed of a 72-hr diet record in clinically stable patients with AIDS (N = 18), ARC (N = 12) and in human immunodeficiency virus (HIV) seropositive controls without significant manifestations of disease (N = 13). Total calorie intake was 39.1 +/- 13.2 kcal/kg/day in AIDS patients vs 34.6 +/- 7.8 kcal/kg/day in ARC patients or 31.9 +/- 17.7 kcal/kg/day in HIV seropositive cases (all p = NS). Likewise, mean protein intakes were similar among the groups and exceeded recommended daily dietary allowance (RDA) guidelines. The mean body weight changes from the inception of illness were -11 +/- 1% in AIDS, -6 +/- 7% in ARC, vs +3 +/- 2% in HIV-seropositive-only cases (p less than 0.05 vs AIDS and ARC). Dietary vitamin and mineral analysis revealed that 88% of AIDS, 88% of HIV seropositive, and 89% of ARC patients were ingesting less than 50% RDA for at least one nutrient. The mean number of deficiencies per patient was 1.8 +/- 1.3 in AIDS, 3.8 +/- 3.5 in ARC, and 2.9 +/- 2.5 in HIV-seropositive-only cases (p less than 0.05 AIDS vs ARC). There were no significant correlations between specific anthropometric measurements and dietary intakes of protein or fat.(ABSTRACT TRUNCATED AT 250 WORDS)