I lost a bunch of weight when I moved to Dublin and started walking everywhere. Then I moved to the Netherlands and lost even more, and got stronger. I didn't particularly try, I just lived somewhere where I used my own body to get around and the "normal" portion sizes were actually somewhat sane (a bag of Doritos here is maybe a third the size of one in the US).
I was 280 pounds when I lived in suburban California. I'm 180 pounds now.
Build bike lanes and public transport, put schools where kids can walk to them, and maybe don't sell a thousand calories of chips in a personal-sized and marketed bag, and it should get better.
As an added bonus you get a lot less air pollution (and noise pollution, etc.) and less people being run over!