processed foods as much as possible. Just keeping bags of chips or whatever around the house adds up, plus pre-prepped items are much pricier than their components.
For example, if you buy rice in bulk (can do that from Amazon) plus shop smart for whatever meat is cheapest, you can save a lot of money. I always stock up on pork butt for instance when it is $1/pound, then cook it all, pull it and freeze in serving portions.
Obviously this takes a bit of time to manage; it's harder than a couple McChickens and a large fry.
Know your caloric baseline and eat healthy foods within it. Bonus, it's also generally cheaper.
And judging from the euros I know/work with, we do eat a lot worse.
it's what we do with the calories we take in. They do significantly more walking (to work, school, and errands) than we do.
That said, the 15-20% increase in obesity doesn't account for a 3x increase in maternal mortality.