That's what a diet is, isn't it?

Or were you thinking that I meant "diet" as in reducing your food to lose weight or something like that? I guess that is the more common use. Sorry if I caused a misunderstanding.

In any case, the specific choice of foods you use is more important than the set they're chosen from. It doesn't seem right to say it competes against a farmers' market. It competes against specific selections of food that may be from a farmers' market.