I recently ran across this interesting website and online tool put out by the lender lendingtree.com. According to their website:
“The total cost of a grocery bill is majorly influenced by consumer shopping habits. According to the U.S. Department of Agriculture (USDA), the national average weekly grocery bill for individuals from ages 19 to 71 is $61.85. By referencing the USDA recommended balanced food plate to create a healthy grocery list and the national average for an individual food budget into consideration, we’ve uncovered how changing one’s diet to reflect a gluten free, organic, vegetarian or vegan diet can significantly affect the cost of their grocery bill.”
Here is one of several graphics at the site.
On that note, I'll also link to a paper I recently published with Bailey Norwood where we compare the food expenditures of self-identified vegetarians and vegans to non-vegetarians.