An ecological systems approach to examining risk factors for early childhood overweight: findings from the UK Millennium Cohort Study.

OBJECTIVE

To use an ecological systems approach to examine individual-, family-, community- and area-level risk factors for overweight (including obesity) in 3-year-old children.

METHODS

A prospective nationally representative cohort study conducted in England, Wales, Scotland, Northern Ireland. Participants included 13 188 singleton children aged 3 years in the Millennium Cohort Study, born between 2000 and 2002, who had complete height/weight data. The main outcome measure was childhood overweight (including obesity) defined by the International Obesity TaskForce cut-offs for body mass index.

RESULTS

23.0% of 3-year-old children were overweight or obese. In the fully adjusted model, primarily individual- and family-level factors were associated with early childhood overweight: birthweight z-score (adjusted odds ratio, 1.36, 95% CI 1.30 to 1.42), black ethnicity (1.41, 1.11 to 1.80) (compared with white), introduction to solid foods <4 months (1.12, 1.02 to 1.23), lone motherhood (1.32, 1.15 to 1.51), smoking during pregnancy (1-9 cigarettes daily: 1.34, 1.17 to 1.54; 10-19: 1.49, 1.26 to 1.75; 20+: 1.34, 1.05 to 1.70), parental overweight (both: 1.89, 1.63 to 2.19; father only: 1.45, 1.28 to 1.63; mother only: 1.37, 1.18 to 1.58), prepregnancy overweight (1.28, 1.14 to 1.45) and maternal employment > or =21 hours/week (1.23, 1.10 to 1.37) (compared with never worked). Breastfeeding > or =4 months (0.86, 0.76 to 0.97) (compared with none) and Indian ethnicity (0.63, 0.42 to 0.94) were associated with a decreased risk of early childhood overweight. Children from Wales were also more likely to be overweight than children from England.

CONCLUSIONS

Most risk factors for early childhood overweight are modifiable or would allow at-risk groups to be identified. Policies and interventions should focus on parents and providing them with an environment to support healthy behaviours for themselves and their children.