You should have seen what I did last year with my BV400. I figured for a four-day, three-night trip that I might as well carry extra stuff. I had everything planned out with about six days of food just in case I ran into problems or wanted to trade with someone. Then I forgot to take extra food (not my first night's planned meal) out of my pack and had to jam more stuff in there. In the end I figure I had enough food at the end of the trip to last three more days. The only item I passed on was some of my extra hot cocoa to a guy and his kid who ran out at LYV. I ended up bringing back tea bags, two Lipton/Knorr pasta sides, a full package of large flour tortillas (fit perfectly at the bottom of the BearVault), a 6 oz package of dry salame, several Clif Bars, oatmeal bars, single-serving mac & cheese packs, peanut butter and unused "Wet Ones Outdoors" wipes. I could have repackaged all that better - especially the wipes.
In the end people have to eat things that makes them feel good. One could live off of 80 Clif Bars for a week, but I think that's rather sad. Most people I saw were packing some sort of comfort food, like hot cocoa or items that didn't necessarily pack maximum calories in the given volume. I had this Kraft "specialty" mac & cheese package, which tasted really good on my third night.
I forgot to bring the Highland Park 12. Absolutely sad. I thought about my loss as I talked to a group of Scots at the Valley backpackers campground. They indicated that they would have been willing to help me finish it off if I had brought it.
I was a little squeamish about storing my used TP with my food, and didn't poop for two days until I got to the Little Yosemite Valley outhouse. I don't think I could do that for a week without getting sick.
I think if I'm going with my wife, we'll handle this differently. I've since gotten a BV350. I figure we can use that to store our non-food items (save maybe the toothpaste) and trash. I doubt I could get her out for more than three nights.
Oh - I thought of something. Perhaps something close to maximum calories in minimum space would be peanut butter. I carried along JIF single-serving packages. As long as I balance it out with other foods, I can tolerate it. I'd probably get cramps (or other maladies) if that was the only food I was eating.