The association between childcare arrangements and risk of overweight and obesity in childhood: a systematic review.

Over 80% of preschool-aged children experience non-parental childcare. Childcare type has the potential to influence weight outcomes, but its impact on childhood overweight/obesity is not well established. This review aims to (i) systematically evaluate the effects of childcare type on childhood overweight/obesity risk and (ii) investigate the impact of childcare intensity and age at commencement. Five electronic databases were searched for observational studies quantifying an association between childcare type ≤5 years and weight outcomes <18 years. Twenty-four studies were included (n = 127,529 children). Thirteen studies reported increased risk of overweight/obesity in children attending informal care (n = 9) or centre care (n = 4) vs. parental care. Seven studies reported decreased risk of overweight/obesity for children in centre vs. 'non-centre' care (parental and informal). Four studies reported no association between informal or centre care and overweight/obesity. Early (<3 years) informal care, especially by a relative, was associated with increased risk of overweight/obesity. Higher intensity childcare, especially when commenced early (<1 year), increased overweight/obesity risk. Later (≥3 years) centre care was associated with decreased risk of overweight/obesity. Early informal care, earlier commencement age and higher intensity represent a risk for childhood obesity. Exploration of the obesogenic aspects of these contexts is essential to inform preventative measures.