Chandon - completely agree! We eat well at meal times, enjoy our food, and certainly don't obsess about portions/calories... I always have pudding when we go out, and if any of us feel particularly hungry at meal times, we will eat how much we need.
But, we don't snack for the sake of it (children have fruit and cheese etc mid afternoon), don't eat processed food as a general rule and I simply don't have rubbish in the house.
We are all active, because we enjoy it. We swim, play tennis, cricket, football, walk, yoga... We are all slim, and have never been on diets in our lives.
As a result, both children love food, are a pleasure to take to restaurants etc, and will happily sit for an hour or so over a meal.
Oh, and my 7 year old will eat most of an adult pizza at a restaurant!
Food and exercise have to be part of your lifestyle, rather than obsessing about portion sizes.