Arthritis Research UK, Medical Research Council, Bupa Foundation, and National Institute for Health Research.

WHAT'S KNOWN ON THIS SUBJECT: Obesity and overweight can seriously affect health outcomes. Many obesity prevention interventions have been proposed, but few have been effective. Motivational interviewing in primary care seems promising, but results in BMI control are controversial and require further investigation.WHAT THIS STUDY ADDS: This is the first study to demonstrate the effectiveness of pediatrician-led motivational interviewing for BMI control in overweight children aged 4 to 7 years. Nevertheless, no effect was observed in boys or when the mother' s education level was low.abstract OBJECTIVE: The aim of this study was to evaluate the effect of family pediatrician-led motivational interviews (MIs) on BMI of overweight (85th $BMI percentile $95th) children aged 4 to 7 years. METHODS:All the family pediatricians working in Reggio Emilia Province (Italy) were invited to participate in the study; 95% accepted. Specific training was provided. Parents were asked to participate in the trial if they recognized their child as overweight. Children were individually randomly assigned to MIs or usual care. All children were invited for a baseline and a 12-month visit to assess BMI and lifestyle behaviors. The usual care group received an information leaflet, and the intervention group received 5 MI family meetings. The primary outcome was the individual variation of BMI, assessed by pediatricians unblinded to treatment groups. RESULTS:Of 419 eligible families, 372 (89%) participated; 187 children were randomized to MIs and 185 to the usual care group. Ninety-five percent of the children attended the 12-month visit. The average BMI increased by 0.49 and 0.79 during the intervention in the MI and control groups, respectively (difference: -0.30; P = .007). MI had no effect in boys or in children whose mothers had a low educational level. Positive changes in parent-reported lifestyle behaviors occurred more frequently in the MI group than in the control group.