Corn syrup is the super weapon here.

More available produce year round. Cheaper imported food from around the world due to dollar's strength. More diverse cuisines in big cities, with a lot better Asian cuisines (sushi!) in general than France, due to large immigrations.

The definition of richness in food is generally heavy in natural fats in proteins, high in butter and cream of a high quality.

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.

In this case, the parent comment used "richness" as a synonym for being diverse and high quality.

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.

Sushi isn't a great food to point to in all of this.

American sushi is full of sugar and most of the specialty rolls are soaked in even more sugar and five different varieties of flavored mayonnaise.