If you happen to know, I've been curious about the water weight of various foods. In particular, I've bought dried or canned beans or tuna or other such things, and attempting to correct for the water weight I normalized on total labeled protein mass (or some other relevant macronutrient) rather than total mass. However, water content still varied dramatically for on-paper identical goods.
Do you happen to know if that's a quirk of US food labeling laws (e.g., they can report a certain number of grams of protein per gram of food so long as water is within a 40% margin), or if there's some other factor at play that would allow macronutrients to actually be similar in qualitatively different products?