And of course New Zealand, Australia, Canada are all in the same boat as well.
Those are all over 30% obesity and climbing (Romania is 38%, nearly at the US levels). The US is of course the leader of the pack, however it's all the same fundamental problem.
My running theory is that there’s more weight-discrimination in Europe, so you’re just less likely to see the overweight/obese in customer-facing positions.
Different European countries have different circuimstances, just like their counterparts, american states. But if we're talking about all of Europe and US, then yes, this is the main reason.
Where are you getting this data from? Nicotine is an appetite suppressant but so is caffeine. I find it hard to believe that smoking alone is the reason for the difference.