61 Cow’s milk fat and child adiposity: a prospective cohort study

Abstract

Abstract Background International guidelines recommend that children older than 2 years of age consume reduced fat (0.1-2%) instead of whole cow’s milk (3.25% fat) to prevent childhood obesity, but these guidelines are consensus-based and have a low GRADE level of evidence. Objectives The primary objective of this study was to evaluate the longitudinal relationship between cow’s milk fat (0.1-3.25%) intake and Body Mass Index z-score (zBMI) in children aged 9 months to 8 years. The secondary objective was to determine the relationship between cow’s milk fat intake and odds of overweight (zBMI >1) and obesity (zBMI > 2). Design/Methods A prospective cohort study of children 9 months to 8 years of age was conducted through the TARGet Kids! primary care research network. The primary exposure was cow’s milk fat consumption (skim (0.1%), 1%, 2%, or whole [3.25%]), measured by parental report. The primary outcome was zBMI, an age and sex adjusted measure of child adiposity. Height and weight were measured by trained research assistants and zBMI was determined according to the WHO growth standards. A linear mixed effects model and logistic generalized estimating equations were used to determine the longitudinal association between cow’s milk fat intake and child zBMI. Results Among children aged 9 months to 8 years of age (N= 7467), each 1% increase in cow’s milk fat consumed was associated with a 0.05 lower zBMI score (95% CI -0.07 to -0.03, p< 0.0001). Compared to children who consumed reduced fat (0.1-2%) cow’s milk, there was evidence that children who consumed whole cow’s milk had 16% lower odds of overweight (OR=0.84, 95% CI 0.77 to 0.91), p< 0.0001) and 18% lower odds of obesity (OR= 0.82, 95% CI 0.68 to 1.00, p= 0.047). Conclusion Guidelines for reduced fat instead of whole cow’s milk during childhood may not be effective in preventing overweight or obesity. Randomized controlled trial data is needed to understand which cow’s milk fat optimizes child growth, development and nutrition.