Background Although parents provide the majority of childcare before they enter formal schooling, preschool-aged children now spend increasing amounts of time in out-of-home care. Childcare centres, in addition to parents, therefore have a significant responsibility for shaping children’s energy-balance behaviours. However, little is known about how the UK childcare environment influences children’s anthropometric indices. We assessed how the amount of time spent in childcare, and how the nutrition, physical activity and overall childcare environment were associated with children’s anthropometric indicators (z-BMI score; waist-to-height ratio (WHR); sum of skinfold thickness (SST)).

Methods We recruited 3–4 year-old children across socio-economic strata from 30 childcare centres in Cambridgeshire, UK. Trained personnel measured children’s height, weight, waist circumference, and subscapular and tricep skinfolds. Parents reported weekly childcare attendance patterns; we assessed the childcare environment relating to obesity (e.g. nutrition and physical activity) using the Environment and Policy Assessment and Observation system. We explored associations between childcare attendance and environment and anthropometric outcomes using two-level hierarchical regression (level 1: child; level 2: childcare centre). All models were adjusted for child ethnicity; maternal educational attainment; maternal BMI; and maternal employment. WHR and SST models were additionally adjusted for child sex and age in months (which are both taken into account when calculating z-BMI scores).

Results 196 children (49% female) from 30 childcare centres provided valid data. Neither time spent in care, nor the nutrition, physical activity, or overall childcare environment were associated with children’s z-BMI score, WHR and SST. These findings remained after adjusting for child and maternal variables; several of the latter were independently associated with the outcomes of interest.

Discussion In constrast to previous international evidence, neither time spent in childcare nor the environment itself were associated with UK preschool-aged children’s adiposity-related outcomes. The childcare environment remains important to the Government’s obesity strategy, and has been central to intervention efforts to prevent or reduce early childhood obesity to date. However, family-level factors also warrant substantial attention when considering obesity prevention strategies for young children.