Yep, the original study looked at the cost per calorie, resulting in a total for a 2000 calorie diet. That's where they got the 36 dollar figure...it was a 2000 calorie diet made up of entirely fruits and vegetables. And as they said in the study, "most people eat a mix of foods". And also, they must have been shopping at fairly pricey markets, because with a little savvy, you can buy 2000 calories of fruits and veggies, even, without spending that much (if you get in season/on sale instead of out of season/imported/expensive). They also only did fresh fruits/veggies, no frozen, and sometimes that results in a higher price as well.
I saw the article here:
http://well.blogs.nytimes.com/2007/1...-healthy-food/
I've always said that you have to make a tradeoff with food...you can have two of these three at once: Healthy, Cheap, and Quick. So you can have healthy, cheap food, but it tends to take a long time to prepare, or you can have healthy, quick food, but it tends to be expensive. My grocery bill stays pretty low (100 a week for the two of us, which is $7 a day for breakfast, lunch, dinner, and snacks...and that's pretty much 100% organic on the produce and probably 75% free range/organic/grass fed on the meats, which we get from local farmers at our farmer's market), and could go lower, because I trade off that convenience for a low price. I cook from scratch, from dried beans, from brown rice that takes a longer time to cook vs. microwaveable varieties, etc.
I also work on eating seasonally, which saves me a TON of money (along with shopping at farmer's markets, which is a great savings here in CA, not necessarily in other places over the country). We get local foods that are in season. Those foods cost less because they don't have to travel miles by air to get to me and my grocery store. They taste better and are more nutritious, too.
So yes, you can get lots of calories cheaply if you buy junk...no disputing that (and there are a multitude of reasons why, including corn subsidies artificially deflating the price of junk that is mostly corn and soy-based). But since our goal at 3FC is rarely "get the most calories for our dollar", and we're rarely eating JUST fruits and vegetables, this is an inaccurate portrayal of actual costs.