Update: Bread loaves are by far the most cph, at 66.666 repeating (not kidding). It's nearest neighbor is turkey at 40, and bread takes up much less stomach space than the next three foods, making it more spammable. Also, oddly enough, milk jugs are not only more cost effective than mystery kegs, they're also not nearly as expensive per unit. As far as buff foods, they're all mostly the same and middle-of-the-road as far as cph, so I think those are fairly balanced.
This game has a lot of potential, and it's quite charming, but math is very important in a game like this. In its current state, unless you're buffing a certain body part, bread loaves are the only food you'll ever want to buy, as nothing beats them even with craving bonuses. Ultimately it's not a huge problem as far as fun factor is concerned, but it is a huge problem if you want the game to encourage buying multiple food varieties.
Also, while doing this, I found myself often accidentally leaving the store when I wanted to buy an item, due to where the buttons are placed. I would recommend placing the back button in the upper left corner, away from all the food menus, and maybe moving the buy button to where back currently is.