We are 2 people, very active, early 30s, live in California. Our average cost per meal, per person, is around $1.50 (our actual spending per day probably would look low b/c the boy gets a lot of meals for free at work).
In my opinion, we eat very very well for what we spend, but in terms of what in our budget is not hardcore mustachian, the grocery bill might be it. For meat & eggs, we eat organic/free range/grass-fed almost exclusively (though we eat very little meat). We also eat a lot of fresh produce, and while I do pay attention to the cost of it and buy the cheaper items (cabbage, carrots, whatever is in season--generally keep it all under $1/lb), it's certainly a bit pricier than some other things might be. Finally, we get some fancy extras like almond milk, dark chocolate, olive oil, etc. And I enjoy cooking as a bit of a hobby so we occasionally buy some more specialized ingredients if I'm trying out a new recipe.
In the past, I have been more hardcore and limited spending to about $30/week (for just myself). It is okay if you like a fair amount of repetition (I could deal with it at the time). For us right now, I'm okay with the fact that we spend a bit more because: 1) we hardly ever go out to eat (if I were serving up lentil soup every night the boyfriend would almost definitely revolt and demand more frequent dinners out), 2) we almost never throw food out, and 3) we are still able to save 70% or more of our income, because of the more frugal decisions we have made in other areas of life. We live in a small apartment to keep rent low, share a single old and paid-off car, don't have cable or even netflix, opted for an ultra cheap $15/month internet plan, etc.
To me, good food and a reasonable variety of it is worth spending some money on, if you have things under control otherwise (also, usually when I see people spending more than we do on food, there are other areas of their finances that are more obvious fruit to pick first. I guess I think the attention paid to food costs often outweighs their importance in the overall budget picture).