Young children who are regularly looked after by their grandparents have an increased risk of being overweight, an extensive British study has suggested.
Analysis of 12,000 three-year olds suggested the risk was 34% higher if grandparents cared for them full time.
Children who went to nursery or had a childminder had no increased risk of weight problems, the International Journal of Obesity reported.
Nearly a quarter of preschool children in the UK are overweight or obese.
The researchers said very little research had been done on the influence of childcare on weight.