Abstract:Abstract: OBJECTIVE To investigate the physical development and prevalence of overweight and obesity among infants and young children aged 1-36months in Yichang,and to explore their influencing factors.METHODS Using simple random sampling,350 healthy infants and young children undergoing one-month check-ups at the Child Health Department of Yichang Maternal and Child Health Hospital between March and September 2021 were enrolled and followed up until age 3.Height and weight were measured using standard methods,with WHO Child BMI standards applied to assess overweight and obesity.All parents completed questionnaires.RESULTS At 12 months,overweight and obesity prevalence rates were 20.85%and 3.40%,respectively;at 24 months,these rates were 12.83% and 2.14%.Prevalence showed an initial rise followed by decline,with relatively higher rates before 12 months and a decrease thereafter. Boys exhibited higher overweight and obesity rates than girls across most age groups.Multivariate unconditional logistic regression analysis identified three risk factors for infant overweight/obesity:maternal BMI(OR=1.507),paternal BMI(OR=1.472),and delayed complementary feeding initiation(OR=2.891).Conversely,birth length(OR=0.454)and delayed weaning(OR=0.781) were protective factors against overweight and obesity.CONCLUSION The prevalence of overweight and obesity among infants and young children under 12 months of Yichang is alarming.The age group should be prioritized for intervention.Controlling parental weight status, prolonging breastfeeding duration,and promplly introducing appropriate complementary foods can effectively prevent overweight and obesity in infants and young children.