I've calculated that I eat for $603/month or $20/day (assuming 30 days in an average month). I do not live in the USA, but "basically the same" ("the West").
I've been trying, but failing, to get a nice list of current average amounts per-country, per-age group/demographics. It would be very interesting to see where I "rank" in such a table, because I feel as if I'm living on poverty levels with 100% frozen junk food (never any take-away, restaurants or any kind of not-at-home food).
Maybe it's a bit misleading because I include not just food but anything I buy from the food store, such as toilet paper, toothbrushes, toothpaste, etc. So this is more of a "total basic necessities" value... not counting the rent, electricity or anything like that, of course.
If a cheeseburger at McDonald's still is $1 USD, that sounds like I'm eating 20 burgers a day, but that's of course not the case. I eat a frozen pizza, another frozen meal... and... um... some canned fruit... and sometimes a pastry or two. And drink a bunch of instant coffee. I truly don't feel like I'm getting almost any food for the amount of money I waste on these grocery orders.