While we continue to battle malnutrition in many communities, a silent epidemic is spreading through our households — one that carries far graver consequences. Obesity, once considered a problem of the affluent, is now clustering within Indian families at an alarming rate, and with it comes a hidden threat that policymakers can no longer ignore: Cancer.
Recent national data paint a disturbing picture of India’s nutritional transition. Nearly 20 per cent of Indian households now have all adult members classified as overweight, while 10 per cent have all adults classified as obese. This suggests shared environmental and behavioural factors. In states like Tamil Nadu and Punjab, two out of every five households have all adults classified as obese. Urban areas show clustering rates which are double those of rural areas, conveying a clear picture of how prosperity and urbanisation are transforming India’s health landscape.
What makes this particularly concerning is its transgenerational nature. When obesity clusters within households, children grow up in environments that normalise unhealthy dietary patterns and sedentary lifestyles, creating cycles of risk that transcend generations.
The evidence linking obesity to cancer is overwhelming. The WHO’s International Agency for Research on Cancer (IARC) has classified excess body weight as a significant risk for cancer. Obesity is directly associated with at least 13 types of cancer: Colorectal, breast (postmenopausal), endometrial, kidney, liver, pancreatic, ovarian, thyroid, meningioma, multiple myeloma, adenocarcinoma of the esophagus, gastric cardia, and gallbladder cancers. An IARC study, published in 2023, the largest of its kind, showed that having a high body mass index increases cancer risk by 17 per cent for people who also have cardiovascular diseases. The American Cancer Society estimates that excess body weight accounts for about 11 per cent of cancers in women and 5 per cent in men in the US.
The biological pathways are clear. Hyperinsulinemia — chronically elevated insulin levels and insulin resistance — promotes obesity and diabetes. Insulin is also a growth factor and when chronically elevated, it can drive malignant transformation. Chronic inflammation associated with obesity represents another deadly pathway. Excess body fat cells (adipocytes) produce inflammatory factors, creating a state of chronic low-grade inflammation that damages DNA and interferes with immune surveillance — our body’s natural defence system against cancer.
Hormonal disruption adds another layer of risk. Fat tissue produces excess estrogen, and dramatically increases risks for hormone-sensitive breast and endometrial cancers. Cardio-metabolic dysfunction completes this deadly quartet. Hyperinsulinemia/ insulin resistance and altered glucose metabolism in the run-up to obesity creates a metabolic/inflammatory environment that favours development of cancer cells, their rapid growth and metastasis.
India’s situation is particularly precarious because we face this obesity epidemic alongside existing healthcare challenges. The economic implications for patients are staggering, too. Cancer treatment can devastate families financially, and when obesity-related cancers strike multiple household members — as clustering patterns suggest they might — the economic burden can be catastrophic. Prevention, therefore, isn’t just a health imperative; it’s an economic necessity.
The household clustering of obesity presents both a challenge and an opportunity. Rather than treating obesity as an individual’s problem, we must recognise it as a health problem that requires targeting the family as a unit for intervention.
The government’s recent commitment to establishing Day Care Cancer Centres in all district hospitals over the next three years, with 200 centres planned for 2025-26, provides a crucial foundation. However, these centres must prioritise prevention alongside treatment. We must scale up existing programmes like the National Programme for Prevention and Control of Non-Communicable Diseases to specifically target high-risk households and individuals. The data show we need concentrated efforts in southern states, urban areas, and affluent households. Regulatory interventions have proved effective globally — implementing taxes on sugary beverages, mandating front-of-pack nutrition labelling, and restricting marketing of ultra-processed foods.
Obesity prevention programmes should target entire households, teaching families to shop for healthier ingredients; prepare meals at home consisting of fresh vegetables, leafy greens, whole grains and fruits; and engage in physical activities as a unit. Workplace and school-based nutrition programmes can break the cycle by creating healthy food environments outside the home. These behaviours can dramatically transform household practices reversing altered metabolic pathways and cardio-metabolic risk factors in a matter of days and weeks.
However, it is crucial to understand that exercise alone cannot undo the harms of unhealthy food intake. While physical activity is essential for overall health, the metabolic damage from ultra-processed foods, excess sugar, poor dietary and inadequate sleep patterns cannot be “burned off” through exercise. Poor nutrition requires dietary intervention, with exercise as a vital but complementary component. Our cities must become laboratories for obesity prevention. This means creating walkable neighbourhoods, ensuring access to affordable fresh farm produce, and designing urban/ work spaces that encourage physical activity rather than sedentary lifestyles.
India’s obesity crisis is not a distant threat — it’s a present reality. Instituting practices to prevent obesity today mean preventing cancer tomorrow. The issue isn’t whether we can afford to implement comprehensive obesity prevention strategies but whether we can afford not to do so. Our families, our healthcare system, and our economic future depend on the choices we make now.
Shalini Singh is director, and Prashant Kumar Singh is senior scientist, ICMR-National Institute of Cancer Prevention and Research, Noida
