Food Insecurity and Weight Faltering: US Multisite Analysis of Young Children's Weight Trajectory.

Background: Food insecurity is associated with poor health and development among young children, with inconsistent findings related to longitudinal growth.

Objective: The aim of this study was to investigate associations between household and child food insecurity and young children's weight trajectory during ages 0 to 2 years.

Design: Longitudinal survey data were analyzed for years 2009 to 2018.

Participants/setting: Racially diverse mothers of 814 children ≤24 months interviewed twice (interval >6 months, mean 11 months) in emergency departments of 4 US cities. Children were included if born at term, with birth weight within 2500 to 4500 g, and weight-for-age z score within ±2 SD at first interview.

Main outcome measures: Weight-for-age z score difference between 2 visits was defined as "expected weight gain" (within ±1.34 SD), "slow weight gain" (< -1.34 SD), or "rapid weight gain" (> +1.34 SD).

Statistical analyses performed: Multinomial logistic regression was conducted to examine adjusted associations between household or child food insecurity and weight-for-age z score differences.

Results: Of 814 children, 83.5% had expected weight gain, 7% had slow weight gain, and 9.5% had rapid weight gain, with mean ± SD of 11 ± 4 months between visits. Child food insecurity, but not household food insecurity, was associated with slow weight gain (adjusted relative risk ratio 2.44; 95% CI 1.16 to 5.13 and adjusted relative risk ratio 1.30; 95% CI 0.69 to 2.51, respectively). Neither exposure was associated with rapid weight gain.

Conclusions: The association between child food insecurity and slow weight gain during the first 2 years of life raises clinical concern. Tracking child food insecurity in addition to household food insecurity can be an effective strategy to prevent weight faltering and to support optimal child growth.