Another iteration wrt the question of how to select food items when volume is a consideration (ex: a trip segment w/o resupply option for a week, in bear country --> 10L for a bear canister/Ursack). Below is a scattergram displaying the number of calories and proteins per ml (
not grams).
Turns out that, yes, peanut butter is in a class of its own. Nutella is another great source of calories per unit of volume. At the other end of the spectrum, banana chips have a disappointing yield (more air than substance). For those worried about my mental health, not to worry -- (1) a back-of-the-envelope calculation has convinced me that it is quite feasible to eat well for 10+ days on a 10L food supply. (2) I am basically done searching for data and narrowing down the options.
One question, perhaps -- one of my preferred option is satay sauce over ramen (melted peanut butter + coconut powder + chili + fish sauce). Unfortunately, it leaves a greasy mess in the pot, requiring soap to clean, whereas, say, with a couscous a rinse with fresh water is enough to clean your pot. Ideas?