Background: Dietary habits formed during the first 5 y of life portend lifelong eating patterns.

Objective: The Synergistic Theory Research Obesity and Nutrition Group (STRONG) Kids 2 birth cohort study aimed to examine multilevel predictors of weight trajectories and dietary habits including individual biology, child socioemotional and behavioral characteristics, family environment, and child care environment over the first 5 y of life. This report describes recruitment strategies, an overview of survey measures, and basic descriptive statistics of the cohort.

Methods: The cohort includes 468 mothers and their offspring. A brief survey was completed at a 1-wk home visit including child's birth weight, intent to breastfeed, collection of an infant stool sample, and additional contact information should the family move. Mothers completed surveys including diet, child temperament, family environment, and child care when their child was 6 wk, 3, 12, 18, 24, 36, 48, and 60 mo of age. Height and weight of the mother and child were collected at each visit. Stool samples of the child were collected at each visit as well as saliva at 1 visit.

Results: Close to half of the mothers were either overweight (24.2%) or obese (25.2%) prepregnancy. At 6 wk of age, 32.9% of the children were overweight and 31.4% were obese based on direct measurement.

Conclusions: The STRONG Kids 2 research team has adopted a socioecological model that accounts for multiple influences on children's health including biological, child social and behavioral, family household organization, and community factors. The study is limited by a relatively educated and nondiverse sample. However, variations in maternal and child weight may inform future prevention programs and policy aimed at improving the diet and health of children under the age of 5 y.This trial was registered at clinicaltrials.gov as NCT03341858.