Objective: To investigate the impact of maternal diet during breastfeeding on atopic sensitization of infants at risk. Design: Prospective cohort study. Setting: Turku University Central Hospital, Finland. Subjects and methods: Altogether 114 infants with a family history of atopic disease were followed during their first year of life. The mothers completed a 4 day food record during breastfeeding just before the infants were 3 months old. Atopic sensitization of the infants was determined by a positive skin prick test result at 12 months. Results: Positive skin prick test reactivity to at least one antigen was detected in 27/114 (24%) infants at 12 months. The energy intake of the mothers was low, mean 8.0 MJ/day (95% CI 7.7-8.3), and the proportion of energy derived from fat was high, mean 36.6 E% (95% CI 35.6-37.6). Atopic mothers had a higher intake of total fat and saturated fat and a lower intake of carbohydrate as a percentage of total energy intake than non-atopic mothers; P=0.017, P=0.050, P=0.004 respectively. Maternal intake of saturated fat during breastfeeding was associated with atopic sensitization of the infant, OR=1.16 (95% CI 1.001-1.36); P=0.048 irrespective of the maternal atopic status. Conclusions: Our results show that an unbalanced maternal diet during breastfeeding may be a risk factor underlying the later development of atopic sensitization of the infant regardless of maternal atopic disease. The observation thus extends findings implying that early nutrition programmes the subsequent health of the child to the risk of developing atopic disease. Sponsorship: Academy of Finland and National Technology Agency. European Journal of Clinical Nutrition (2000) 54, 702-705 | 
