Infant weight in relation to nutritional intake and morbidity in northern Thailand.

A cross-sectional study of 58 infants (age range 2-53 weeks) was carried out in a rural area of northern Thailand. Total dietary intake (energy and protein from breastmilk and supplementary food) was measured directly during continuous observation over 48 h of randomly selected study subjects in their homes. Associations between infant weight and total energy intake, total protein intake and morbidity were analysed by multiple regression analysis. Up to 6 months of age, heavier infants had larger energy intakes, when age and birthweight were taken into account. In the 7-12 months age group, heavier infants consumed more protein and had fewer respiratory infections. Weaned infants older than 6 months were significantly heavier and consumed more protein than infants of similar age who were still receiving breastmilk. The lower protein intakes of the latter infants were due to the low protein concentration of breastmilk compared with supplementary food.