Not Overweight, Not Diabetic — So Why Do You Have Fatty Liver?

Medical insights by Dr. Chetan Kalal, DM (Hepatology), Liver Transplant Physician, Gleneagles Hospital, Mumbai

Picture this: you’re in your early thirties. Your weight is normal, you exercise regularly, and you have no family history of diabetes or high blood pressure. Yet a routine check-up reveals fat has quietly built up in your liver. A few years ago, this would have been considered a rare, puzzling exception. Today, it isn’t.

Liver specialists across India are seeing a steady rise in exactly this kind of patient — people who fall completely outside the traditional risk profile for fatty liver disease. Dr. Chetan Kalal, DM (Hepatology) and liver transplant specialist at Gleneagles Hospital, has been tracking this shift closely and breaks down the real reasons behind it.

The Old Assumption Is Outdated

Fatty liver was long considered a disease of obesity, diabetes, and heavy alcohol use. But newer research has redrawn that picture. The condition is now formally known as MASLD — Metabolic Dysfunction-Associated Steatotic Liver Disease — and, as Dr. Chetan Kalal points out, it can affect people who look, and even test, perfectly healthy on the surface.

So What’s Actually Causing It?

1. Genetics — the PNPLA3 factor

According to Dr. Chetan Kalal, the single biggest reason is genetic predisposition. Variations in genes such as PNPLA3 make certain individuals naturally more prone to storing fat in the liver — regardless of their body weight. This genetic variant is notably more common in South Asian populations, particularly Indians, which helps explain why so many lean, fit Indians are being diagnosed with fatty liver.

2. Diet quality, not just calorie count

Dr. Chetan Kalal emphasizes that it isn’t just how much you eat — it’s what you eat. Regular consumption of sugary drinks, refined flour (maida), packaged snacks, and ultra-processed foods forces the liver to convert excess sugar into fat. This happens gradually and silently, meaning fatty liver can develop even without any visible weight gain.

3. The gut-liver axis

Researchers are increasingly focused on the relationship between gut health and liver health. Dr. Chetan Kalal notes that processed food, frequent antibiotic use, chronic stress, and poor sleep all disturb the balance of beneficial gut bacteria. This imbalance raises inflammation in the body, which in turn disrupts how the liver processes fat — putting even “low-risk” individuals in the danger zone.

4. Hormonal and metabolic triggers

Conditions such as hypothyroidism, PCOS, insulin resistance, and cholesterol imbalances can trigger fat accumulation in the liver well before diabetes ever develops, Dr. Chetan Kalal explains.

The Real Danger: It’s Silent

Perhaps the most concerning part, per Dr. Chetan Kalal, is that early-stage fatty liver produces no symptoms at all. Most people discover it incidentally, during an ultrasound or a routine blood test. Caught early, lifestyle changes can fully reverse it. Left unchecked, it can progress to liver inflammation, fibrosis, cirrhosis, liver failure, and even liver cancer.

The Takeaway

Looking fit and having normal blood sugar doesn’t guarantee a healthy liver. If a scan flags fatty liver — even in someone slim and metabolically “normal” — Dr. Chetan Kalal advises not to dismiss it. A proper fibrosis screening and metabolic risk assessment is essential to identify the underlying cause. Timely diagnosis and the right lifestyle changes remain the most effective way to prevent serious, irreversible liver damage.

---

This article is based on medical insights shared by Dr. Chetan Kalal, DM (Hepatology) & Liver Transplant Specialist, Gleneagles Hospital, Mumbai, as originally reported by Navarashtra. It is intended for general health awareness only and is not a substitute for personal medical consultation.