Association of Body Mass Index between Adolescents and their Parents in Mumbai and Kolkata: A Population-based Study

Introduction: Adolescent overweight and obesity as measured by body mass index (BMI) seem to be increasing at an alarming rate in urban populations. Parental BMI plays an important role in their adolescent's BMI. Overweight and obesity coexisting with undernutrition in adolescents is an important public health challenge in low- and middle-income countries (LMICs). We present results from a population-based study on adolescents' prevalence of BMI and its association with their parents' BMI in Mumbai and Kolkata, India.

Methods and materials: Multistage random sampling of households was used to select adolescents aged 12-14 years and one of their parents in 2019-2020. In Mumbai, 843 adolescents, and in Kolkata, 913 adolescents and one of their parents were interviewed independently by trained field investigators. Height and weight were measured using standardized procedures. Adolescents' BMI categories were defined using Centers for Disease Control and Prevention (CDC) recommendations. For parents, the BMI was categorized using Asian cut-off categories into underweight (BMI < 18.5), normal weight (BMI: 18.5-22.9), overweight (BMI: 23.0-27.0), and obese (BMI > 27.0). Multivariate logistic regression was used to determine the relationship between parental BMI and adolescents' BMI.

Results: In Mumbai, 15.7% and in Kolkata, 21.1% of adolescents were overweight or obese. Nearly 80% of mothers and 70% of other parents were either overweight or obese. The mothers of adolescents who were overweight or obese showed a high risk of their adolescent being overweight [odds ratio (OR): 4.16 (1.36-12.73)] or obese [OR: 18.53 (2.02-170.44)] in Mumbai and [OR: 4.45 (1.25-15.80)] and [OR: 8.81 (1.40-55.33)] in Kolkata respectively after adjusting for adolescent's gender and head of the household's highest level of educational attainment.

Conclusion: Adolescents' overweight/obesity status is strongly associated with their mothers' BMI in urban India. This association may reflect both genetic and environmental effects. The present study highlights the high prevalence of adolescent overweight and obesity in these urban populations and underscores how important it is to identify effective public health strategies for the primary prevention of childhood obesity.