It works out to ~$500.00 (Canadian) for 6 people , 2 are adults, 3 are teenagers and my youngest is 11 (and eats like an adult

)
We also have a Lab, but this does not include her food as I buy it in bulk about twice a year, she would cost about $45.00 in food per month.
We are very limited in our coupons.
I (or the teenagers)do the majority of our cooking from scratch.For a variety of reasons we just don't eat out.
We can look at other people's figure (to get a ballpark idea

. But depending on the ages of our families, whether they pack lunches or eat at home, special dietary concerns etc. this will influence our spending.
I remember reading about Amy Dacyzyn (Tightwad Gazette) and how dissappointed she was when she figured out the "national average" and then compared it to her family for grocery purchasing/consumption. She thought "Wow, I'm in line but I thought I was doing so much better." Turns out she was comparing her monthly average to the national weekly average. (I've felt like that at times)
I just know from my shopping habits, lack of processed foods, ability to provide varied nutritious dishes consistently that for the rest of the population with similar size and aged families that I'm doing okay.
I think that the numbers reflected here are so much lower than national averages. I think the people on this board do think/act differently.