We compared macronutrient intake, food insecurity, and anthropometrics in breastfeeding women: 40 HIV-positive women not yet on antiretroviral therapy and 40 HIV-negative women. Calculated deficits at 2 weeks were 517 kcal per day for HIV-positive women vs 87 kcal per day surplus for HIV-negative women (P = 0.01) and 29 g protein per day for HIV-positive women vs 16 g protein per day for HIV-negative women (P = 0.04). Food insecurity scores were 11.3 for HIV-positive women vs 7.8 for HIV-negative women (P < 0.01). Enhanced dietary education together with macronutrient supplementation may be required to improve health outcomes in HIV-positive women and their infants.