OK sort of like if I used the word distributed in a technical discussion to mean a lot of people in different countries are using our application.
on edit: just seems a weird word to use when that has a precise meaning for food, if they had said a richer selection of food I would understand. But as the discussion was about what makes Americans unhealthy with shorter lifespans, and the unhealthiness of Americans is often synonymous with being overweight, saying it's because Americans eat rich food just doesn't seem to make any sense if what they mean is Americans have a wide selection of food to choose from.
American butter and cream is ludicrously bad. There is just enough taste to it to make the stuff inedible.
Sushi is not a rich food.
Sauces with a lot of butter and fats in them are 'rich', pastries can be rich, depending mainly on the fattiness of the cream and butter.
on edit: French cuisine is generally thought of as one of the richest in the world, hence my use of them as an example.