India is urbanising at a breakneck pace and this brings with it huge shifts in the way people eat, move and live. These changes in lifestyle are closely associated with increasing metabolic diseases like diabetes, fatty liver disease and obesity. But the real source of the problem goes even deeper — to our biology.

Indians survived millennia of famine and hardship because they went through backbreaking manual labour in the fields. In order not to starve in those bad old days, our bodies evolved what scientists call the “thrifty genotype.” When this happened, the body became so good at saving and storing energy that bodies began to burn less calories than they stored. Every calorie was put to good use, and what was left over got saved as fat in case society couldn’t manage during the lean times.

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But today, that ancient survival mechanism is working against us. But the modern environment is literally the exact opposite — food is everywhere, easy, cheap, hyper-processed and calorie-dense. Meanwhile physical activity has plummeted as a result of city living and sedentary jobs.

This juxtaposition of old genetics and new lifestyle is particularly striking in young Indians. These same genes that shielded us then now provide a way for our bodies to readily store fat more efficiently, especially around the abdominal area and in the liver. Metabolic diseases are therefore emerging early and are growing at an unprecedented pace.

Thrifty Phenotype: when early life nutrition predisposes adult disease

Adding to the genetic vulnerability is the “Thrifty Phenotype,” which refers to adaptations made by the fetus during pregnancy, says Dr. Rajiv Kovil, Head of Diabetology and weight loss expert, Zandra Healthcare and Co-founder of Rang De Neela Initiative. He says Many Indians are born with low birth weight due to generations of maternal undernutrition.

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· Smaller pancreas beta-cell mass

· Lower metabolic reserve

As adults, when they encounter a high-calorie diet, sugary beverages, and sedentary lifestyle, their body cannot cope. The mismatch between a “conservative” metabolic setup and an “abundant” environment accelerates insulin resistance, visceral fat deposition, and fatty liver and very often, at a young age.

The Genetics of Fatty Liver: The PNPLA3 Connection

Research has identified certain genetic variations that make Indians particularly susceptible to fatty liver disease. One of the most important is the PNPLA3 (patatin- like phospholipase domain-containing protein 3) gene variant, says Dr. Kovil.

People carrying this variant are more likely to:

Accumulate fat in the liver even without obesityDevelop fatty liver at a younger ageProgress faster to MASH (Metabolic dysfunction associated steatohepatitis)Have associated metabolic complications including diabetes and heart disease

In simple words, some Indians can develop severe fatty liver even if they are not overtly overweight.

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Fatty liver is no longer a benign diagnosis. It is an early warning sign , a metabolic “red flag.”

Increased insulin resistanceProgression to prediabetes and diabetesHigher risk of heart attacks and strokesGreater visceral adiposityChronic inflammation and hormonal imbalance

In fact, fatty liver often precedes diabetes by several years. By the time fasting glucose rises, the metabolic storm is already brewing. The rapid shift in India’s food ecosystem happened within just one generation. Our genes and physiology have not had time to adapt.

What happened instead?High-Carb Diet Culture: Our traditional plates are overloaded with rice, wheat, potatoes, and sugars, often exceeding 70–80 percent carbohydrate content. In vulnerable individuals, this quickly converts to triglycerides and gets stored in the liver.“Coca Colonization”: The invasion of sugary beverages, fast food, packaged snacks, and ultra-processed calories has impacted metabolic health. Liquid sugar is converted into liver fat.Also Read | Oestrogen protects against obesity-related fatty liver, says studySedentary Urban Lifestyles: Modern work culture, long commutes, screen- based work, and reduced physical activity have caused weight gain.Rapid Urbanization in One Generation: What took Western countries 50–60 years occurred in India in just 15–20 years. Our biological systems are still calibrated for scarcity, not abundance.What should young Indians Do?

The solution lies in early screening, prevention, reducing refined carbohydrates and saying NO to sugary beverages, increasing muscle mass through strength training, prioritizing sleep and stress control and getting regular liver and metabolic health checks

Awareness, prevention, and timely intervention can reverse this trend and protect an entire generation from the burden of metabolic disease.