MILK Symposium review: Milk consumption is associated with better height and weight in rural Nepali children over 60 months of age and better head circumference in children 24 to 60 months of age

Child undernutrition afflicts >150 million children worldwide, contributing to poor child growth, increased risk of infections, and loss of developmental potential. Animal-source foods (ASF) can ameliorate these problems by providing high-quality, high-density, and bioavailable protein and micronutrients. However, many children in developing countries lack ASF in their diet, although generally milk is the ASF most often consumed. Nevertheless, the relation of ASF-and that of specific ASF-to child growth in these contexts has been difficult to define, as has the association between diet and child and household factors in influencing growth outcomes. To better understand these relationships, we evaluated child growth by age groups (6-23 mo, 24-60 mo, and >60 mo) in relation to ASF consumption in rural Nepal. We used an observational study design that leveraged a data set generated through a 3-yr longitudinal controlled impact evaluation of a community-development intervention. Child anthropometry and 24-h diet recall were obtained at 5 household visits. At baseline, children were generally undernourished: 47% were stunted, 46% underweight, 17% wasted, and 24% microcephalic. Patterns of undernutrition varied with age but improved somewhat over time. Over the 3-yr period of study (9,283 observations), ASF were consumed infrequently: milk in 28% of assessments, meat in 27%, and eggs in 15%. Consumption patterns differed by age group, with younger children (6-23 mo) consuming more milk and less meat than children 24 to 60 or >60 mo. Consumption of even a single ASF at any of the 5 surveys was associated with greater growth in bivariate analysis. After adjustment for household (group assignment, survey round and its interaction, wealth, income, livestock and land ownership, maternal education) and child factors (age, sex, baseline anthropometry), mixed-effect linear regression analysis showed that milk consumption related to higher height for age and weight for age z-scores for children >60 mo of age and to higher head circumference z-score for children age 24 to 60 mo. For children >60 mo, egg consumption also related to higher weight z-scores. Household and child factors also influenced these outcomes. Of the ASF, milk had the strongest and most consistent relationship to child growth. Better measures of diet intake could reveal stronger associations between diet consumption patterns and child growth. Regardless, milk may be a key ASF to target for growth promotion among undernourished rural Nepali children.