That sounds to me like a false equivalence. The cause of obesity is not that food is plentiful because different rich countries have different obesity rates. There is something else driving this issue and, in my opinion, is the prevalence of processed foods and use of highly processed seed oils.
It’s probably a combination of factors, but look at the rate of change of obesity rates. Obesity rates have been going up almost everywhere. Essentially the rest of the world has been catching up to America. America was the first country where food was so abundant that it was essentially limitless for the majority of the population.
Perhaps the effect of limitless food on obesity rates takes time to manifest and is compounded in successive generations.
Obesity is 100% caused by food is plentiful, with a catch....
There has to be excess calories in the first place, much like there must be oxygen for there to be a fire (don't you try to get florine involved in this).
Humans eating behavior seems to be driven by the first few years of our lives. If you eat like garbage as a kid, it follows you into adulthood. The US was (somewhat, there are still plenty of other even fatter countries) first with the TV to counter advertising that taught us that Trix was part of a balanced breakfast and that we should carry a coke wherever we go.
Other countries likely had confounding factors that slowed the excess calorie uptake. For example common traditional meals that were only replaced slowly. Other things that can tip the scale are things like higher walkability in their cities.(for example higher walkability in the US correlates with lower body mass).
But as stated, those confounding factors only slowed the fattening, it didn't stop it and the EU now is growing in weight just like the US did in the past.
