I think that is both right and wrong.
Yes, Americans on average eat too much. Yes, Americans on average don’t move enough. But I am convinced from my personal experience that there can be - not that there always is, but there can be - more to it.
My wife was obese to morbidly obese from the day we met to the day she died. So was her mother (WAY more so). So was her father. So was her brother. So were/are most of her aunts and uncles and cousins - particularly in the descendants of her maternal grandparents. Who - although I never met them - were also certainly at least overweight if not obese.
You can’t convince me that those two parents, 6 of their 7 children, the majority of their grandchildren, and plenty of their great grandchildren are all overweight just because they ate too much and moved too little. There has to be a genetic component to this. Not always. Not everywhere. Maybe not a majority. But in some significant number of cases.
The problem I have is when people put the blame squarely on the shoulders of the obese and say that their weight problem is entirely of their own making. It’s their own fault for eating too much and moving too little. They just need more self control to eat less and move more.
It turns the issue into what is effectively a moral judgement on the obese. And it places those pre-disposed to a thinner physique on a pedestal of higher morality. “Look at them! They don’t eat too much. They don’t sit around all day. That’s why they are at a lower weight. Do what they do.”
I’ve said before, and I’ll repeat it to my dying day - I saw how hard my wife worked to keep her weight down. She ate a pittance. She ate about half of what I did. Yes, she could have moved more, and in her younger days she did. But the weight just wouldn’t go down. Bariatric surgery helped. For a while. That helped her lose about 75 pounds over the long run.
When you fight the same battle for 20 or 30 years, you get tired of fighting it. You get tired of never getting ahead. So I’m not going to shame the obese for being obese.
When you say “that’s all there is to the obesity problem,” you are shaming the obese for lacking the will power to eat less and move more. You are saying their problem is entirely of their own making. You are denying that there may be - and I believe likely are - other contributing factors in plenty of cases. If you don’t address those contributing factors, eating less and moving more doesn’t really solve the problem. It may help with the symptoms while leaving the problem untouched.
I really wish medical science would look harder at this issue.