I agree with you 100%. I spend a lot of time in Europe and I'm always surprised how slim and trim everyone is, considering their food has so much fat. For example, French people eat food drenched in butter, they love their fatty beef and duck, they have so much cheese and dessert and chocolate, but have you ever seen a fat Parisian? The reason is three-fold in my opinion:
1) They walk EVERYWHERE. You're either walking or riding a bike. People hardly use cars there.
2) The portions are smaller. Whenever I go to the States (I live in Canada), I can hardly believe the gargantuan portions they serve in American restaurants.
3) They eat more natural food and they take longer to eat so they don't rely on fast food (junk). They don't eat a lot of high-fructose corn syrup, GM food, etc..., and their lunch hours are not 10 minutes of eating on their desk. Have you ever sat in the Louvre gardens around lunchtime on a weekday? It's full of office workers eating leisurely.