Weight Loss: Have you ever noticed that some people eat very little but still gain weight, while others eat freely and stay lean? Dr Saurabh Sethi (a gastroenterologist trained at AIIMS, Stanford and Harvard) recently explained why this happens. According to him, it’s not about willpower or portion control, but your metabolism.
In a recent Instagram post, Dr Sethi shared insights that can change how you approach dieting. He shared that understanding your body’s engine is the first step to achieving lasting weight control.
Why Eating Less Doesn’t Always Work For Weight Loss
Dr Sethi explained that everyone’s metabolism works differently. He said, “Basal Metabolic Rate (BMR) is the energy your body burns just staying alive – breathing, thinking, digesting and pumping blood. Some people are born with a faster BMR due to genetics, thyroid function, hormones or higher muscle mass.”
This means that even if you eat very little, a slower metabolism can make it harder to lose weight. People with a higher BMR naturally burn more calories (even at rest), allowing them to eat more without gaining fat. Those with slower metabolisms burn fewer calories, making weight loss more difficult.
Dr Sethi also pointed out that less muscle EQUALS fewer calories burned. Crash diets, long-term calorie restriction, or natural muscle loss with age can lower the body’s calorie-burning ability. Muscles burn three to five times more calories than fat, even when resting, making them crucial for weight control.
How Muscles, Hormones And Lifestyle Impact
Muscle mass isn’t the only factor. Hormonal imbalances like insulin resistance make it easier to store fat and harder to burn it. This is common in conditions like fatty liver, PCOS, prediabetes and diabetes. Other causes of weight gain include hidden stress, high cortisol, poor sleep and post-diet metabolic adaptation.
Dr Sethi noted that people who eat freely but stay lean usually have:
- A higher metabolic rate
- Better insulin sensitivity
- More daily movement
- Greater muscle mass
Even small daily movements add up, helping the body burn calories consistently. The key isn’t eating less – it’s optimising your metabolism through muscle building, stable hormones, regular activity and good sleep.
By strengthening muscles, supporting hormone balance and staying active, anyone can naturally burn more calories and make weight loss easier and sustainable.
