> Is anybody serious claiming it is?
Most Americans.
https://www.nytimes.com/2016/11/01/health/americans-obesity-...
Most Americans.
https://www.nytimes.com/2016/11/01/health/americans-obesity-...
There are certainly genetic factors that make some people vulnerable but our genetics haven't changed that much in the last 30 years. Obesity has.
The combination of genetics with our lifestyle and dietary context is where it's at IMO.