Six-month old healthy infants are identified through community surveys in the study area. 1920 infants meeting set criteria are randomised into receiving the following intervention between 6 and 18 months of age: 1) standard treatment from 6-18 months (i.e.no supplements, with delayed intervention between 18-30 months of age (ST-DI), 2) 10 g / day milk-containing LNS (LNS-10gM), 3) 20 g / day milk-containing LNS (LNS-20gM), 4) 20 g / day milk-free LNS (LNS-20gNoM), 5) 40 g / day milk-containing LNS, (LNS-40gM) 6) 40 g / day milk-free LNS (LNS-40gNoM). The families receive the food supplements at 2-weekly intervals and the participants undergo a morbidity evaluation weekly, a limited development assessment at 4-weekly intervals and anthropometric evaluation at 26-week intervals and laboratory analyses at enrollment and at 18 months. Growth outcome analyses are done at 18 and at 42 months of age.