Lower protein in infant formula is associated with lower weight up to age 2 y: a randomized clinical trial

Abstract

Background: Protein intake during infancy was associated with rapid early weight gain and later obesity in observational studies. Objective: The objective was to test the hypothesis that higher protein intake in infancy leads to more rapid length and weight gain in the first 2 y of life. Design: In a multicenter European study, 1138 healthy, formula-fed infants were randomly assigned to receive cow milk-based infant and follow-on formula with lower (1.77 and 2.2 g protein/100 kcal, respectively) or higher (2.9 and 4.4 g protein/100 kcal, respectively) protein contents for the first year. For comparison, 619 exclusively breastfed children were also followed. Weight, length, weight-forlength, and BMI were determined at inclusion and at 3, 6, 12, and 24 mo of age. The primary endpoints were length and weight at 24 mo of age, expressed as length and weight-for-length z scores based on the 2006 World Health Organization growth standards. Results: Six hundred thirty-six children in the lower (n ¼ 313) and higher (n ¼ 323) protein formula groups and 298 children in the breastfed group were followed until 24 mo. Length was not different between randomized groups at any time. At 24 mo, the weight-forlength z score of infants in the lower protein formula group was 0.20 (0.06, 0.34) lower than that of the higher protein group and did not differ from that of the breastfed reference group. Conclusions: A higher protein content of infant formula is associated with higher weight in the first 2 y of life but has no effect on length. Lower protein intake in infancy might diminish the later risk of overweight and obesity. This trial was registered at clinicaltrials.gov as NCT00338689.

Growth, body composition and hormonal status of growing pigs exhibiting a normal or small weight at birth and exposed to a neonatal diet enriched in proteins

“…In infants (29) , the difference in body weights induced by a rise in protein intake persisted in the year following the intervention period. Nevertheless, it should be noted that the reported differences tended to decrease during this period.…”

“…More recently, it has been reported in a large randomised controlled trial that infants receiving a formula with a higher protein content between 15·5 d (median age) and 12 months of age exhibited a higher growth at the end of the intervention period (29) . In contrast, a very recent study indicates that feeding a proteinenriched formula without extra energy for 6 months after term did not affect growth of pre-term infants (30) .…”

Early nutrition and long-term health: a practical approach

“…More recently, a large multicentre randomised trial of > 1000 term infants has provided support for an association between early nutrition and risk of later obesity. Infants randomised to a higher-protein diet during the first year of life have greater BMI at 2 years of age (32) .…”

Breast-feeding and later risk of CVD and obesity: evidence from randomised trials

“…The growth acceleration hypothesis is also now supported by data from randomised trials of early nutrition in healthy term infants (38,39) . Infants randomised to receive growth-promoting, nutrient-enriched formulae (thought at the time the studies were initiated to be beneficial) were found to have higher BP (31) and greater fat mass (40) at age 5-8 years.…”

“…In a randomised trial of high-v. low-protein infant formulae in healthy term infants with normal birthweights, those who received a higher-protein formula showed faster early growth and had significantly higher BMI, with the effect persisting at age 2 years. Infants randomised to receive the lower protein formula had a growth pattern more similar to that of a breast-fed reference group (39) .…”