Different protein intake in the first year and its effects on adiposity rebound and obesity throughout childhood: 11 years follow-up of a randomized controlled trial

Background and Objectives Infant feeding affects child growth and later obesity risk. We examined whether protein supply in infancy affects the adiposity rebound, body mass index (BMI) and overweight and obesity up to 11 years of age. Methods We enrolled healthy term infants from five European countries in a double blind randomized trial, with anticipated 16 examinations within 11 years follow-up. Formula-fed infants (n = 1090) were randomized to isoenergetic formula with higher or lower protein content within the range stipulated by EU legislation in 2001. A breastfed reference group (n = 588) was included. Adiposity rebound and BMI trajectories were estimated by generalized additive mixed models in 917 children, with 712 participating in the 11 year follow-up. Results BMI trajectories were elevated in the higher compared to the lower protein group, with significantly different BMI at adiposity rebound (0.24 kg/m(2), 0.01-0.47, p = 0.040), and an increased risk for overweight at 11 years (adjusted Odds Ratio 1.70;1.06-2.73;p = 0.027) but no significant difference for obesity (adjusted Odds Ratio 1.47;0.66-3.27). The two formula groups did not differ in the timing of adiposity rebound, but all children with obesity at 11 years had an early adiposity rebound before four years. Conclusions Compared to conventional high protein formula, feeding lower protein formula in infancy lowers BMI trajectories up to 11 years and achieves similar BMI values at adiposity rebound as observed in breastfed infants