BACKGROUND: Childhood obesity has become a public health challenge globally. Existing studies have indicated a potential link between maternal dietary macronutrient compositions and subsequent weight changes in their offspring during early childhood, although few studies have been conducted through early adulthood. OBJECTIVES: We aimed to investigate the relationship between maternal macronutrient intake before or during pregnancy and offspring body weight from late childhood till early adulthood. METHODS: We included 5715 children from the Growing Up Today Study 2 (GUTS2) (mean 11.8 y old at baseline in 2004) born to 4731 mothers who participated in the Nurses' Health Study II (NHSII) during 1989-1995. Diet during or before pregnancy was assessed using a validated food frequency questionnaire (FFQ) in 1991 and 1995. Age- and sex-specific body mass index (BMI) 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 associations of interest. RESULTS: The mean (SD) maternal macronutrient percent energy intake during pregnancy was 19.3% (3.1) for protein, 51.2% (6.6) for carbohydrates, and 30.8% (5.0) for total fat. For diet during pregnancy, after multivariate adjustment for maternal and offspring risk factors, compared with the lowest quartile, the highest quartile of trans fatty acid consumption was associated with a 0.20 unit (95% confidence interval [CI]: 0.00, 0.40) increase in BMI z-score without a significant linear trend (P-trend = 0.06). A positive association with BMI z-score was also observed for total fat intake (β: 0.21
95% CI: 0.05, 0.36
P-trend = 0.02) when replacing total carbohydrate, and vice versa (β: -0.24
95% CI: -0.40, -0.08
P-trend = 0.02 for total carbohydrate intake). For diet before pregnancy, none of the macronutrients were associated with offspring BMI z-score or the risk of overweight or obesity. CONCLUSIONS: Higher fat, especially trans fat intake, during pregnancy was positively associated with higher body weight among offspring. Other macronutrients from various food sources were not associated with the offspring weight. Overall, these data suggest that, apart from trans fatty acids, other macronutrient composition of maternal diet may have minimal impact on offspring body weight in this well-nourished population.