ImportanceIn 2009, the US National Academy of Medicine (NAM) released revised gestational weight gain (GWG) guidelines, which were established primarily for White North American women and may be unsuitable for Asian women. In 2021, the Chinese Nutrition Society (CNS) released its GWG guidelines, but their applicability requires re-examination.ObjectiveTo compare the differences between the CNS and NAM recommendations for GWG in association with health outcomes in the offspring of Chinese women.Design, Setting, and ParticipantsIn this bidirectional cohort study, children in China were recruited at age 3 years from 2017 to 2018, with 2 follow-up visits over the next 2 years (between September 2017 and September 2020). Information during pregnancy was retrieved from medical records. Data analysis was performed from October 2021 to January 2022.Main Outcomes and MeasuresGWG was classified as insufficient, appropriate, or excessive according to the CNS and NAM guidelines separately. Children’s height, weight, fat mass, fat-free mass, and percentage of body fat were measured at each visit. Body mass index, fat mass index, fat-free mass index, weighted κ score, risk ratio values, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.ResultsA total of 3822 children (1996 boys and 1826 girls; mean [SD] age, 3.79 [0.30] years) were enrolled; after exclusions, 3170 term singleton children were recruited and were followed at 4 and 5 years of age. According to the CNS guidelines, the prevalence rates were 14.1% for insufficient GWG, 48.1% for appropriate GWG, and 37.9% for excessive GWG, whereas the rates according to NAM guidelines were 39.7% for insufficient GWG, 37.2% for appropriate GWG, and 23.1% for excessive GWG. The weighted κ value for the classification agreement between the 2 guidelines was 0.530 (95% CI, 0.510-0.550). For the appropriate GWG group, the rates for low nutritional levels did not differ between the 2 guidelines, but the rates for high nutritional levels were significantly lower under CNS guidelines than under NAM guidelines. When the sensitivity, specificity, PPV, and NPV with respect to the mothers who maintained appropriate GWG were used to estimate the nonhigh nutritional status of their offspring, generally higher values based on the CNS guidelines were found compared with those based on the NAM recommendations.Conclusions and RelevanceThese findings suggest that the GWG recommendations promulgated by the NAM are higher than the CNS guidelines, with the latter more suitable for Chinese women.