Abstract P409: Maternal Macronutrient Intake at Pregnancy and Offspring Growth Trajectory Before Adulthood: A Prospective Analysis in the Growing Up Today Study 2 Cohort

Background: Childhood obesity has become a public health challenge globally, with increasing prevalence worldwide. Existing studies have indicated a potential link between maternal macronutrients intake and subsequent weight changes in their offspring during childhood. However, the long-term relationship between maternal macronutrient consumption at pregnancy and the growth trajectory of offspring into adulthood remains unclear. Objectives: We aim to investigate the relationship between maternal macronutrients intake at pregnancy and the trajectory of the offspring BMI z-score, as well as the risk of becoming overweight or obese before adulthood. Method: We included 5,700 children from the Growing Up Today Study 2 born to 4,697 mothers who participated in the Nurses’ Health Study II . Diet was assessed using a validated food frequency questionnaire in 1991 approximately during or before the pregnancy at issue. Age- and gender-specific BMI thresholds described by the International Obesity Task Force were used to define overweight and obesity in childhood and adolescence. Multivariable linear and log-binomial regression models with generalized estimating equations were used to evaluate the association between maternal macronutrients intake at pregnancy and offspring BMI z-score trajectory and the risk of overweight or obesity. Results: During follow-up, 2145 (37.6%) GUTS2 participants met the criteria of overweight or obesity.After multivariate adjustment for maternal, offspring risk factors, total maternal total energy and carbohydrate percent energy, comparing to the 1 st quartile, the highest quartile of total protein consumption at pregnancy was associated with 0.14-unit β: 0.14 (95% CI: 0.02, 0.26; P-trend = 0.03) increase in BMI z-score, while no significant association was observed for the risk of offspring overweight or obesity RR: 1.17 (95% CI: 0.94, 1.46; P-trend = 0.12). The relationship persisted for the top quartile of animal protein energy intake β: 0.14 (95% CI: 0.01, 0.27; P-trend = 0.03), but not for vegetable protein consumption. Intakes of dietary fats and carbohydrates were not associated with BMI z-score or risk of overweight or obesity. Furthermore, individual macronutrient subgroups, such as saturated fats, mono- and poly-unsaturated fats, or whole grains and refined grains, were not associated with the outcomes of interest, either. Conclusion: Maternal animal protein intake at pregnancy is positively associated with higher offspring BMI z-score before adulthood, but not the risk of developing overweight or obesity during childhood. Other macronutrients are not significantly associated with these childhood body weight outcomes. Overall, these data suggest that the macronutrient composition of maternal diet at peri-pregnancy period has minimal impact on offspring body weight in this well-nourished population.