This sounded absurd to me at first from my modern perspective, but it seems that this was actually true when the movie came out. Europeans ate roughly 100 more calories per day than Americans did.
https://ourworldindata.org/food-supply
Calories in Calories out is a meme and has been debunked. The only thing that matters is the nutritional content and how it affects your hormones.
shareWell, fast food is characteristically American, which is why 'fat Americans' is very much a meme in Europe. That's why it was kind of surprising to hear an American say the same thing about European food. The fat Americans meme isn't fully true as there are states in the US that have obesity rates that are on par with Europe, but the meme persists because Europeans look at the fattest states in the US and see them as representative of the country and because fast food chains come from America.
https://bigthink.com/strange-maps/two-maps-and-one-graph-comparing-obesity-in-america-and-europe/