Understanding the Roots of Childhood and Adolescent Obesity

Childhood obesity has become one of the most urgent global public health concerns. Around thirty-seven million children under the age of five already live with overweight or obesity. High body mass index in infancy and early childhood predicts weight gain throughout life and increases the risk of non-communicable diseases such as diabetes, cardiovascular conditions, and certain cancers. The consequences are long-term, affecting mental health, scholarly outcomes, quality of life, and economic productivity.

Obesity can be addressed by reducing weight through changing the calorie balance (less intake compared to expenditure of calories). However, this needs high motivation and persistence. Findings of a recent study reveal that childhood obesity cannot be effectively addressed by such interventions targeted solely to households. This implies that the food and physical environments that surround families also need to be improved.

The study published in The Lancet and co-authored by Professor Kaumudi Joshipura, Dean of the Bagchi School of Public Health, Ahmedabad University, analysed data from nearly ten thousand participants across seventeen randomised controlled trials that began before twelve months of age. The research found that parent-focused interventions, although beneficial for improving awareness, did not significantly reduce the risk of obesity during the first two to three years of life.

As children grow into adolescence, these structural factors intersect with social and behavioural influences. A separate qualitative study explored snacking behaviours among adolescents in an urban setting. The study found that choices were strongly shaped by peer norms, parental restrictions, school food environments, and the constant visibility of advertisements for packaged and fried foods. Even when aware of the risks, many adolescents preferred energy-dense, nutrient-poor snacks because they were cheap, accessible, palatable, and socially validated.

The study, co-authored by Neha Rathi, Visiting Professor at Ahmedabad University’s Bagchi School of Public Health, highlights that adolescent eating is influenced by a web of relationships and contexts rather than individual decision-making alone. Schools, families, and communities all play a role in shaping the culture of food. By documenting these layered influences, the research points to the need for interventions that combine regulation with education. Making healthier foods more appealing and affordable, strengthening school meal policies, and curbing the marketing of unhealthy snacks could have lasting effects on adolescent well-being.

Together, the two studies trace the continuum of risk from infancy to adolescence, showing how early nutritional environments evolve into social patterns that sustain obesity. They offer critical evidence for a life-course approach to public health, one that integrates family-based programmes with multisector reforms in food production, marketing, and urban design. This could include policies and practices that improve access to affordable and nutritious foods, reduce the marketing of sugar-sweetened and ultra-processed products, promoting physical activity through schools and communities in public spaces, changing social norms and designing environments that support active living. Such measures are crucial to reduce exposure to environments that encourage unhealthy habits throughout the lifespan.

Through such research, the Bagchi School of Public Health is deepening understanding of how health outcomes are shaped by the interaction of biology, behaviour, and environment. By connecting evidence from early childhood and adolescence, Ahmedabad University scholars are helping inform policies that can create healthier futures for India’s young population and improve health equity.