Food insecurity is considered to be an important contributor to HIV associated wasting in sub-Saharan Africa. Low body mass index (BMI) is a strong risk factor for early mortality during antiretroviral therapy (ART). Nutritional supplementation has become standard of care in wasted patients starting ART in many countries in the region, but there is no unequivocal evidence base for this intervention. Against this background, we performed a retrospective study to compare food supplementation versus no nutritional intervention in wasted adults starting ART in Blantyre, Malawi. All patients received free nevirapine, lamivudine, and stavudine. Participants in an effectiveness trial of two food supplements received either corn-soy blend (CSB) or ready-to-use food spread (RUFS) during the first 14 weeks of ART. Results were compared with a historical control group receiving no food supplement that was part of an observational cohort study of outcomes of the same ART regimen. Characteristics on initiation of ART were similar in the three groups, except the use of cotrimoxazole prophylaxis which was more frequent in the food-supplemented groups. Linear regression analysis showed that increase in BMI was greatest in the RUFS group and better in the CSB group than in those receiving no food supplementation at 14 weeks. These differences were no longer significant at 26 weeks. Lower BMI, CD4 count and hemoglobin, WHO clinical stage IV, male gender, and not receiving cotrimoxazole prophylaxis were independent risk factors for mortality at 14 and 26 weeks in the logistic regression analysis. Supplementary food use was not directly associated with improved survival.