LOL, whereas I have no trouble whatsoever seeing how people spend at the upper limit, but I still have trouble understanding how people spend at the thrifty end, even after reading endless threads and working to reduce our bill.
We are 2 adults and 3 cats (if I broke the pet stuff out of groceries, we'd probably shave a bit off). NOT including booze, we have no trouble whatsoever spending between the Low/Mod category (averaging 550$/month for the past few years). And that is down a bit from previous years, because I finally started tracking costs/price book/and buying meat on sale.
And that's with my husband (usually) eating lunches out, and me eating only twice per day!
Some of the cost is probably because I tend to buy greener, more expensive cleaning products, etc. But I think it's mostly diet choices. We eat a lot of salmon (which is essentially $10/meal), a lot of nuts and nut butters, not a lot of cheap fatty meat (I haven't had hamburger in years), lots of fruit, tons of fresh produce, not a lot of filler carbs. We ate very differently when we were young...lots of cheap carbs, hot dogs, hamburgers, etc, when we were in college and our food bill was definitely at the thrifty end then.
But, I am still working to bring costs down. It's an ongoing project. I've been buying the bigger, cheaper cuts of fattier meat (beef roasts, pork shoulder, etc) on sale, and it definitely saves money. The problem is, I find fatty meats pretty gross. I grew up eating game and free range chicken, so I like lean meat. Hell, I only just in the past couple years trained myself to like dark meat chicken in stews! Plus, with cholesterol issues, fatty meat isn't optimal anyway.
I think we're just going to transition to vegetarian 2 to 3 days per week, which will fix this problem.