Neighborhood Food Environment in Pregnancy Is Prospectively Associated With Childhood Obesity Risk

Objectives: Childhood obesity is a growing epidemic, with increasing evidence recognizing the role of the neighborhood food environment. Pregnancy is a critical window of susceptibility, but no prospective studies examined the prenatal neighborhood food environment in relation to childhood obesity. We examined the association of prenatal exposure to low-income-low-food-access (LILA) neighborhoods with childhood obesity risk. Methods: This is a population-based cohort study of mother-child dyads at Kaiser Permanente Northern California (KPNC) in 2011-2023. We defined prenatal LILA neighborhood exposure if the mother resided in pregnancy in a census tract with (1) poverty rate ≥20% or median family income ≤80% of the state-wide median family income and (2) ≥500 people or 33% of the population live >0.5 or 10 miles from the nearest supermarket in urban or rural areas, respectively, according to the US Food Access Research Atlas. We estimated risk of childhood obesity (sex-specific BMI-for-age ≥95th percentile using CDC growth charts) by prenatal LILA neighborhoods using modified Poisson regression adjusting for age at delivery, race/ethnicity, parity, prepregnancy BMI, insurance, and smoking and alcohol use in pregnancy. Results: Among 439,001 mother-child dyads followed up for mean ± SD 5.4 ± 3.1 years, 25.5% resided in LILA neighborhoods in pregnancy; and 14.4%, 16.4%, and 22.3% of children had obesity at 2-4, 5-7, and 8-10 years, respectively. Prenatal LILA (vs. non-LILA) neighborhoods were associated with higher childhood obesity risk at 2-4 (adjusted relative risk 1.19; 95% CI 1.17-1.21), 5-7 (1.21; 1.18-1.24), and 8-10 (1.21; 1.17-1.25) years. Associations in all age groups varied by race/ethnicity and prepregnancy BMI (P-for-interaction < .0001). At 8-10 years for example, associations were strongest in Asians (1.32; 1.21-1.43), then Whites (1.18; 1.10-1.27) and Hispanics (1.08; 1.03-1.14) and reversed in Blacks (0.88; 0.79-0.97). Associations were strongest in mothers with normal weight (1.29; 1.18-1.40), then overweight (1.13; 1.06-1.21) and obesity (1.05; 1.00-1.09). Conclusions: Prenatal LILA neighborhoods are associated with higher childhood obesity risk. Our findings may inform early risk stratification and public health efforts to curb the obesity epidemic. Funding Sources: KPNC Health Equity NHLBI R01HL157666.