Relationship between early childhood non-parental childcare and diet, physical activity, sedentary behaviour, and sleep: A systematic review of longitudinal studies

BackgroundThe rising prevalence of childhood obesity is a global public health concern. Evidence suggests that exposure to non-parental childcare before age six years is associated with increased risk of obesity, diet, and activity behaviours (physical activity, sedentary behaviour, and sleep). However, findings are inconsistent and mostly from cross-sectional studies, making it difficult to identify the direction of causation in associations. This review identified and synthesised the published research on longitudinal associations between non-parental childcare during early childhood, diet, and activity behaviours.MethodsSeven databases were searched using a predefined search strategy. Results were independently double-screened through title/abstract and full-text stages according to predefined criteria. Included studies were tabulated, and evaluated for risk of bias using the Nutrition Evidence Library Bias Assessment Tool.ResultsOf 18793 references screened, 13 studies met eligibility criteria and were included in the review. Eight studies reported on diet and seven studies reported on activity behaviour outcomes (three on physical activity, three on sedentary behaviour, and one on sleep). These studies included results on 89 tested childcare:outcome associations. Of 63 associations testing diet outcomes, 37 (59%) were null, and the remainder showed inconsistent patterns. There was an indication of a potential benefit of Head Start providers (vs other care, including parental) on dietary behaviours. Of 26 associations testing activity behaviour outcomes, 22 (85%) were null, and the remainder were inconsistent. Most studies (92%) did not use (or did not report using) valid and reliable outcome measures, and outcome assessors were not blinded (or it was unclear if they were blinded) to children’s exposure status (77%).ConclusionsThe scarce available literature indicates little and mixed evidence of a longitudinal association between exposure to non-parental childcare before age six years and diet or activity behaviours. This reflects a paucity of research, rather than clear evidence of no effect. There is an urgent need for studies investigating the longitudinal associations of non-parental childcare on diet and activity behaviours to assess potential lasting effects and mechanisms. Studies should assess whether and how associations vary by provider and child sub-groups, as well as differences by intensity and duration of care.