Why Belly Fat Increases After 30 Even Without Changing Your Diet: AIIMS-Trained Doctor Explains

A protruding belly is not just an aesthetic concern—it can also be a gateway to various health problems. Many people wonder why their belly starts to grow after the age of 30, even when their diet and exercise routines remain unchanged. Gastroenterologist Dr. Saurabh Sethi, trained at prestigious institutions like AIIMS and Harvard, explains the science behind this common phenomenon.

Why the Change Happens After 30
According to Dr. Sethi, many people begin to notice changes in their body after crossing 30. Foods and workouts that once kept the belly flat become less effective, and even small indulgences can lead to noticeable weight gain. These changes are not random—they are linked to natural aging processes.

Muscle Mass Declines
After 30, muscle mass decreases by 3–8% every 10 years. With fewer muscles, the body burns fewer calories at rest. Losing 1 kg of muscle can significantly reduce daily calorie expenditure, making it easier for fat to accumulate.

Glucose Accumulation
Muscles handle 70–80% of glucose disposal. When muscle mass decreases, glucose remains in the bloodstream, increasing the likelihood of fat being stored around the abdomen.

Reduced Insulin Sensitivity and Hormonal Changes
Insulin sensitivity declines by 4–5% every decade after 30. As a result, the same amount of carbohydrate intake causes higher blood sugar spikes, promoting abdominal fat storage. Additionally, hormones such as growth hormone, testosterone, and estrogen decrease, while cortisol increases. This combination accelerates fat accumulation around the belly.

The Risk of Deep Belly Fat
This leads to an increase in deep visceral fat, which accumulates around vital organs faster than subcutaneous fat. Visceral fat contributes to insulin resistance, inflammation, fatty liver, prediabetes, type 2 diabetes, and high triglycerides, making it a serious health concern.

Tips to Manage Belly Fat After 30

• Consume 1.2–1.6 grams of protein per kilogram of body weight daily.
• Engage in strength training at least three times a week.
• Regular walking improves insulin sensitivity.
• Ensure 7–8 hours of quality sleep every night.

Disclaimer: This article is based on an Instagram reel by Dr. Saurabh Sethi. Navbharat Times does not take responsibility for the accuracy or effectiveness of the information. Always consult a medical expert before trying any new health regimen.