people in poland (eastern europe in general) do tend to look healthier on account of them eating less fast food; there are a ton of hot eastern european girls.
obesity in america is partly a result of something america has that very few other places do. during the world wars, the US seemed to realise the importance of self sufficiency. the UK almost had to surrender due to only having 6 weeks worth of oil left at one point. no oil (fuel / energy source in general) = no boats, planes, trains, cars, vans, trucks, tanks, factories. the same applies to food in an even more important sense, no food = dead regardless.
america launched the farming initiative and now grows an absolutely insane amount of food by comparison with most places, prioritizing corn & wheat.
it's in a ton of western food now. the base recipe is refined carbohydrate + some kind of oil + salt; chips, crisps, dough, pastry, source etc.
the US has tried to find a lot of other uses for it; e.g. making plastics, fuel.
but they need to maintain a constant farming infrastructure to ensure its available if need be.
a side effect of that has been the population has been kind of swamped with junk surplus over the last half century.
and
>WE DON'T HAVE PUBLIC TRANSPORT
this.
one thing that does kind of suck about america is the public transport / lack of pavements. but the lack of pavements is partly due to the massive distances between a lot of places.
i like walking and will walk an hour back and forth to work but even i'm not walking 20 miles into and out of work per day.
also, many things in the US are considerably cheaper than they are in europe.