Exclusive breast-feeding until 6 months is advised by the WHO as the best practice to feed infants. Yet, some studies have suggested a gap between energy requirements and the energy provided by human milk for many infants at 6 months. In order to assess the adequacy of WHO recommendations in 6-month-old Senegalese lactating infants, a comprehensive study was designed to measure human milk intake by the dose-to-the mother 2H2O turnover method. Infants' energy intakes were calculated using daily breast milk intake and the energy content of milk was estimated on the basis of creamatocrit. Of the fifty-nine mother–infant pairs enrolled, fifteen infants were exclusively breast-fed (Ex) while forty-four were partially breast-fed (Part). Infants' breast milk intake was significantly higher in the Ex group (993 (sd 135) g/d, n 15) compared with the Part group (828 (sd 222) g/d, n 44, P= 0·009). Breast milk energy content as well as infants' growth was comparable in both groups. However, infants' energy intake from human milk was significantly higher (364 (sd 50) kJ/kg per d (2586 (sd 448) kJ/d)) in the Ex group than in the Part group (289 (sd 66) kJ/kg per d (2150 (sd 552) kJ/d), P< 0·01). Compared with WHO recommendations, the results demonstrate that energy intake from breast milk was low in partially breast-fed infants while exclusively breast-fed 6-month-old Senegalese infants received adequate energy from human milk alone, the most complete food for infants. Therefore, advocacy of exclusive breast-feeding until 6 months should be strengthened.