['The potential for small-quantity lipid-based nutrient supplements (LNS) to promote growth and development after 6 mo of age is currently being investigated. Because infants self-regulate energy intake, consumption of LNS may reduce breast milk intake and potentially decrease the beneficial effects of breast milk.', 'The objective was to test the hypothesis that the breast milk intake of 9- to 10-mo-old rural Malawian infants receiving LNS would not be lower than that of infants receiving no supplementation.', 'This was a substudy of the International Lipid-based Nutrient Supplements (iLiNS) DOSE trial, in which 6-mo-old infants were randomly assigned to receive 10, 20, or 40 g LNS/d containing 56, 117, or 241 kcal/d, respectively, or no LNS until 18 mo of age. A subset was randomly selected to estimate breast milk intake at 9-10 mo of age with the dose-to-mother deuterium oxide dilution method. The noninferiority margin was <10% of total energy requirements.', 'Baseline characteristics (n = 376) were similar across groups. The mean (± SD) daily breast milk intake of unsupplemented infants was 730 ± 226 g. The differences (95% CIs) in mean intake of infants provided with 10, 20, or 40 g LNS/d, compared with controls, were +62 (-18, +143), +30 (-40, +99), and +2 (-68, +72) g/d, respectively. Non-breast milk oral water intake did not differ by group (P = 0.39) and was inversely (r = -0.22, P < 0.01) associated with breast milk intake.'] Do lipid-based nutrient supplements decrease breast milk intake of Malawian infants?