TUESDAY, Sept. 16, 2025 (HealthDay News) -- Parent-focused behavioral interventions seem to be insufficient for preventing obesity at age 24 months, according to a review published online Sept. 10 in The Lancet.Kylie E. Hunter, Ph.D., from the University of Sydney in Australia, and colleagues conducted a systematic review and individual participant data meta-analysis to examine the effectiveness of parent-focused early childhood obesity prevention interventions. Randomized controlled trials commencing before 12 months of age and examining parent-focused behavioral interventions to prevent obesity in children, compared with usual care, no intervention, or attention control, were included. The primary outcome was body mass index (BMI) Z score at age 24 months.Forty-seven trials were completed and eligible; 18 of these trials (38 percent) assessed the primary outcome. Individual participant data were obtained for 17 of the trials, including 9,128 participants (97 percent of eligible participants). The researchers found no evidence of an effect of interventions on BMI Z score at 24 months. The findings were robust to prespecified sensitivity analyses. No evidence was seen for differential intervention effects for prespecified subgroups."Obesity is in large part driven by environmental and socio-economic factors that individuals are unable to change," Hunter said in a statement. "Parents play a vital role, but our study highlights that they cannot be expected to reduce childhood obesity levels alone."Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter