I think your assumption is closer to reality than my assumption. Here are three examples in my family:

1. My son’s BMI is in the 90th percentile for boys of his age. He doesn’t eat more than other boys.
2. As she shrinks in height, my mother’s BMI has shifted into the “obese” range though she looks mildly overweight. She doesn’t eat more than other people of her age and height.
3. Another of my family members looks overweight for the last 5 to 10 years, but she doesn’t eat a lot when I share a meal with her.

On the other hand, calorie intake is hard to estimate. My mother might be eating a bit too much fatty stuff, so her calorie intake might be 20% higher than other people. Over decades that would add up.

My view is

• Overweight people’s BMI is still determined by calorie balance i.e. [ intake – expenditure ]
• The total weight of food intake is usually not visibly higher
• But calorie intake is very hard to visualize. Our perception is completely unreliable.

There are individual differences from person to person. It’s possible for one overweight individual to have actually lower calorie intake than other people but still not losing weight. That might be a medical condition. I think most healthy people are not like that. So if my son really cuts down on calorie, he will surely lose weight over time.

I can’t starve my son. I want him to experiment to find a new diet that’s personally satisfying yet lower calorie. I have found many foods that work for myself – I call them calorie bargains.