Risks and Benefits of Weight Gain in Children With Undernutrition.

Importance: Previous studies in low-resource settings have emphasized the risks of childhood weight gain for increased body mass index (BMI) and systolic blood pressure (SBP) in adulthood. However, these studies have not directly compared the risk of extra weight against the benefit of increased adult height. Objective: To test the hypothesis that a continuous 1-SD increase in weight from age 1 to 10 years was associated with taller stature in adulthood but not with increased risk for obesity or hypertension. Design, Setting, and Participants: This prospective cohort study, called the Dogon Longitudinal Study, is a 21-year population-based multigenerational cohort study conducted from 1998 to 2019 in 9 Dogon villages on the Bandiagara Escarpment in Mali. A mediation analysis was conducted in 2024 to calculate the estimated total effect on adult SBP of a 1-SD weight increase over the mean throughout the first decade of childhood. This estimated total effect was decomposed into estimated direct and indirect effects. Children aged 5 years or younger on April 15, 1998, as well as all children born from that date to July 2, 2000, were eligible to participate in the F1 generation. Exposures: Weight and height trajectories from age 1 to 10 years. Main Outcomes and Measures: For the mediation analysis, adult SBP was the outcome, and the mediators were height and BMI at age 21 years. The mediation analysis used linear mixed models for SBP, adult height, and adult BMI. Results: A total of 1348 participants (645 females [47.8%], 703 males [52.2%]) of the F1 generation contributed 10 081 SBP measurements to the analyses. These participants completed the study and had a median (IQR) of 12 (11-14) follow-up visits from enrollment (at median [IQR] age of 1.59 [0.62-3.44] years) to last measurement (at median [IQR] age of 21.14 [19.47-23.14] years). After adjusting for both parents' height and SBP (F0 generation), analyses included 433 females and 501 males, with 3384 and 3770 SBP measurements, respectively. The total effect on adult SBP of being 1 SD above the mean, instead of at the mean, childhood weight trajectory was 1.9 (95% CI, 0.9-2.8) mm Hg for females and 3.2 (95% CI, 2.3-4.2) mm Hg for males. This total effect was mediated by an indirect effect through adult height of 2.3 (95% CI, 0.9-3.7) mm Hg in females and 3.9 (95% CI, 2.4-5.4) mm Hg in males and by an indirect effect through adult BMI of 2.6 (95% CI, 2.0-3.2) mm Hg in females and 1.4 (95% CI, 0.6-2.2) mm Hg in males. The direct effect on SBP was -3.1 (95% CI, -4.5 to -1.6) mm Hg in females and -2.1 (95% CI, -3.2 to -0.9) mm Hg in males. A 1-SD weight increase in childhood was associated with a 1.6% increase in the prevalence of obesity in females and no increase in the prevalence of obesity in males. The percentage of individuals whose SBP was 130 mm Hg or higher increased by 0.5% in females and 3.7% in males. The mean (SE) height at age 21 years increased by 3.0 (0.5) cm in females and 4.1 (0.6) cm in males. Conclusions and Relevance: The findings of this cohort study of an undernourished population in Mali supported the hypothesis, suggesting that the risks of 1 SD in childhood weight gain for hypertension and obesity in adulthood were small compared with the benefits of taller stature.