Written in Our Genes? Understanding the Genetic Roots of Obesity

Dr Shehla Shaikh, Dept. of Endocrinology, Saifee Hospital and HN Reliance Hospital, Mumbai, India

Obesity is not just about lifestyle—our genes significantly shape susceptibility, disease progression, and response to treatment.

For a long time, obesity has been viewed largely through the lens of lifestyle—what we eat and how much we move. However, growing scientific evidence makes one thing clear: genetics plays a powerful role in shaping an individual’s risk of obesity. Far from being a matter of choice alone, obesity often reflects how our biological blueprint interacts with today’s environment.

Research shows that hundreds of genes influence appetite regulation, energy expenditure, fat storage, and even food preferences. Variations in pathways linked to the brain’s appetite centers, hormonal signaling, and the gut–brain axis can predispose individuals to weight gain from an early age. In rare cases, single-gene defects lead to severe, early-onset obesity, while in most people, the combined effect of multiple genes subtly increases vulnerability over time.

Importantly, genetic risk does not mean genetic destiny. Lifestyle factors such as diet quality, physical activity, sleep, and stress can either amplify or blunt inherited risk. What genetics does change is our understanding of why weight loss is harder for some individuals and why responses to the same treatment can vary widely.

This insight is reshaping obesity management. The future lies in personalized care—using genetic and biological information to guide prevention strategies and tailor therapies, from targeted medications to novel gene-based approaches. Recognizing obesity as a biologically complex disease rooted partly in our genes is a crucial step toward more effective, empathetic, and sustainable care.

(Source: Tonin G, Eržen S, Mlinarič Z, Eržen DJ, Horvat S, Kunej T, Klen J. The Genetic Blueprint of Obesity: From Pathogenesis to Novel Therapies. Obesity Reviews. 2025:e13978. )