Sources and pattern of protein intake and risk of overweight or obesity in young UK twins

High protein intake in young children is associated with excess gains in weight and body fat, but the specific role of different protein sources has yet to be described. The study objective was to investigate the role of different types of protein in the post weaning stage on weight, BMI, and overweight/obesity at 60 months. Intakes of animal, dairy and plant protein and a dietary pattern characterising the variation in protein types at 21 months of age were estimated using a 3-day diet diary in a cohort of 2154 twins; weight and height were recorded every three months from birth to 60 months. Longitudinal mixed effect models investigated associations between sources of protein intake or dietary pattern scores and BMI, weight, and overweight/obesity from 21 months up to 60 months. Adjusting for confounders, dairy protein intake at 21 months was positively associated with greater weight (46 g (95% CI 21;71) and BMI up to 60 months (0.04 kg/m2 (95%CI 0.004;0.070)) and the odds of overweight/obesity at 3 years (OR 1.12(95% CI 1.00;1.24)). Milk showed associations of similar magnitude. A dietary pattern low in dairy and high in plant protein was associated with lower weight gain up to age 60 months, but not overweight/obesity. Intake of dairy products in early childhood is most strongly associated with weight gain, compared to other protein sources. A dietary pattern characterised by lower protein intake and greater diversity in protein sources at 2 years of age may confer a lower risk of excess weight gain.