Protein intake in children: Effects on health in later life
There is substantial evidence that the protein content of breastmilk, when compared to most infant formulae, exhibits significant differences for the long-term health of a child. Several meta-analyses have shown that bottle-fed infants exhibit higher adiposity both in infancy and later life as a result of the higher protein content when compared to breastfed infants. Whilst this evidence has been well accepted, recent research has started to explore the role of complementary feeding in the development of childhood obesity.
A recent study, that formed part of the Gemini twins cohort, explored the role of protein intake in the complementary feeding period in relation to excess weight gain and adiposity of young children.1 The investigators explored whether a higher proportion of protein intake from energy beyond the complementary feeding stage is associated with greater weight gain, higher body mass index (BMI), and risk of overweight or obesity in children up to 5 years of age. Dietary intake was collected by using a 3-day diet diary when the children had a mean age of 21 months. Weight and height were collected every 3 months, from birth to 5 years. Longitudinal models investigated associations of protein intake with BMI, weight, and height, with adjustment for age at diet diary, sex, total energy intake, birth weight/length, and rate of prior growth and clustering within families.
Logistic regression investigated protein intake in relation to the odds of overweight or obesity at 3 years and 5 years of age. It was found that a higher proportion of energy from protein during the complementary feeding stage is associated with greater increases in weight and BMI in early childhood in this large cohort.
It is thus recommended that protein intake in the first few years of life be considered in feeding both toddlers and children. It is clear from this study that, although protein intake is necessary for growth and development of the child, that one must keep the amount and quality of protein in mind when feeding children in the early years.1
Whole cow’s milk is also known to be detrimental to infants, mainly due to its low iron content.2 The negative association with iron status has led to recommending the introduction of formula feeding in infancy during the complementary feeding period or when breastfeeding ceased. However, recent studies suggest that consuming whole cow’s milk in infancy and early childhood also has unfortunate effects on growth, especially weight acceleration and development of overweight in childhood.2 It is thus recommended that one considers the timing of the introduction of whole cow’s milk into the diet of children due to its high protein content. Furthermore, it is recommended that lower protein milk feeds are considered when feeding children in these influential developmental years.
In conclusion, we are only beginning to understand the complexities associated with early metabolic programming and the associations to the diet of the infant and child. Recent studies are exploring the relationship of early protein intake in the first years of life. Several findings indicate that lower protein intake, not only in the first six months of life but even into early childhood, may have beneficial effects on later health indicators such as obesity incidence. It is thus recommended that healthcare providers consider the quantities and quality of protein that a child consumes during these significant developmental years.
References
Pimpin et al. Dietary protein intake is associated with body mass index and weight up to 5 y of age in a prospective cohort of twins. Am J Clin Nutr, 2016;103:389–97.
Thorsdottir, I. & Thorisdottir, A. V. Whole Cow’s Milk in Early Life. Clemens RA, Hernell O, Michaelsen KF (eds): Milk and Milk Products in Human Nutrition. Nestlé Nutr Inst Workshop Ser Pediatr Program, 67: 29–40.
