(very soy Harvard PMC voice) "Noooo, you can't say that obesity isn't evil!!! Your methodology must be faulty if it doesn't help me rationalize my anti-worker bourgeois moralism!"
We have the receipts of these Mad And On NPR eugenicists who are being honest about their Malthusian fascism: "We have no choice but to shame fatties or else our health system will be overloaded because people will become too fat".
Funny how that PMC pro-capitalist, anti-worker class betrayal of the 1990s/2000s is repeating during covid19. "You need to listen to experts, they want to help you!!!" Stop lying, demon. These treacherous grifters probably only fear mongered about obesity so they can get research funding, like how they wanted to be friends with Epstein
Personally it’s not the amount of fat you have on you, but how active you are. Being fat often goes hand in hand with a lack of activity and it is the lack of fitness that puts you at risk of a lot of bad health outcomes. There was a scientific paper where if you normalized everything except 30 or more mins of exercise a day, even the folks with higher BMIs had better health outcomes.
And lack of fitness or exercise activity is often a byproduct of systemic environmental issues like driving to work, no time to work out, no public spaces, lack of access to gyms, etc.
I imagine it's a number of different factors at play. Some people might need to keep their bf% below a certain threshold in addition to just exercise, I believe fatty liver (a risk factor for liver disease) is determined by how the body distributes fat reserves. But as you're saying making society more pedestrian and bike friendly would probably do a lot to increase people's health outcomes.
Definitely not an encouragement to work out 30 minutes and eat an entire pizza. But in reality, a lot of people's exercise levels (mine included) are sub-optimal primarily because of the way society is built around traveling really fast in a vehicle everywhere you go, instead of having walkable cities, dense urban areas, etc. So you need to actively save time to work out and by the point, you get home or feel motivated enough to do that, it is often too tiring or unappealing, or we are socially isolated. I don't like working out and doing calisthenics by myself. I remember playing flag football consistently for over a year before I got my girlfriend/now wife, and I stopped showing up.
I think one advantage that the Healthy At Any Size movement provides is that you learn to love your body (and therefore care for it), give it the respect it deserves (including good diet and exercise). A lot of people that hate their bodies think of exercise as a punishment for being gluttons or think diets have to be extreme and that's no way to maintain a good system of living.