Maternal Stress Moderates the Relationship of Food Insufficiency with Body Mass Index Trajectories from Childhood to Early Adulthood among U.S. Rural Youth

Background: Findings on the relationships between household food insufficiency (HFI), maternal stress, and youth body mass index (BMI) are mixed, possibly due to cross-sectional study designs and measurement issues. Furthermore, little is known about how childhood exposure to HFI and maternal stress influences BMI into young adulthood among rural youth. We aimed to determine the independent and moderating relationships of HFI and maternal perceived stress on youth BMI trajectories from age 9 to 24 years. Methods: We used longitudinal data from rural New York youth ( n  = 341). At youth age 9 years, parents reported HFI using a reliable one-item measure, and mothers responded to the 10-item Perceived Stress Scale (PSS; range: 0-40). BMI was calculated (kg/m 2 ) from objective measures of height and weight at 9, 13, 17, and 24 years. Multivariate random-intercept trajectory models estimated the relationships of HFI and PSS on BMI trajectories ( p  < 0.05 for main effects, p  < 0.10 for interactions). Results: At age 9 years, 16.4% experienced HFI and mean (standard deviation) BMI and PSS were 18.4 (3.6) kg/m 2 and 7.7 (2.9), respectively. HFI and PSS were not associated with BMI trajectories ( p  = 0.18, p  = 0.64, respectively), but their interaction was significant ( p  < 0.01). Each one-unit increase in PSS was associated with 0.6 (0.2) kg/m 2 higher mean change in BMI trajectories for youth in food-insufficient, compared with food-sufficient, households. Conclusions: Higher levels of maternal stress in food-insufficient households may lead to greater increases in BMI from childhood to young adulthood. Public health interventions should simultaneously address parental stress and quality food access among low-income rural households.