The U.S.A. obesity prevalence was 41.9% in 2017 – March 2020 according to https://stacks.cdc.gov/view/cdc/106273
I think this country has a particular issue with obesity and here is my hot take as to why that is.
I personally find that people who work more physically demanding jobs tend to not have trouble with obesity, I think this is primarily due to the fact that they exercise their body throughout the day.
Someone like me who works on a computer all day and sits in a comfy chair isn't exerting nearly as much energy as someone who is working in a field or a waitress standing all day.
Here is my theory... I think the people of the U.S.A. are leaning towards extremes. Extreme obesity, and extreme fitness.
Allow me to explain.
For the population becoming more sedentary, they have two choices, either do some supplemental exercise to offset the effects that sitting all day and poor nutrition, or they can choose to become obese.
Gyms are more popular nowadays than ever before. People have gym memberships, people share workout videos on YouTube, fitness is a cool thing to do now.
Being at the gym to counter the effects of a sedentary job doesn't just counter the job itself, it goes beyond to a higher degree.
What I mean by this is that a gym, and specifically weight training, targets specific muscles that would not normally be exposed to such demand.
As someone gets stronger, weights get heavier, and now suddenly you are developing a physique that is more extreme.
Not going to the gym and sitting at home and drinking soda ( high fructose corn syrup ) will have the exact opposite effect, you will become obese.
So in conclusion, the transition to more desk jobs and less manual labor is creating a larger divide in this country. We have people becoming more obese, and people becoming very swole.