Although this has been discussed multiple times in the past and will be again in the future, I felt the need to add my own ideas to the pile. So let’s get our turnout gear against the flame war, because I want to talk about the food system.
To start of, this is not directly about the controversial vitamin system. However, it does propose more simulationist aspects the game. As of writing this post, the two main components to the consumables are hunger and thirst. These are tracked independently of each other, although many food items affect both. Especially the hunger value seems to be a combination of satiation and caloric intake, which to me seems a bit simplistic in contrast to the complexity and depth that otherwise permeates this game. My proposed armchair game designer suggestion is as follows.
The main food system, not counting vitamins and other potential macronutrients should be comprised of three stats: hydration, energy, and satiation.
Hydration would be conceptually simple, how much water your body contains. The difference from the current thirst would be that there is no hard cap on how much you could drink. Upon drinking excessive amounts water poisoning could be possible, but otherwise the water loss should be proportional to your current hydration. If you had a lot of water, your hydration loss would be higher as the body expels excess water through multiple means. If you were dehydrated (with associated debuffs) your body would conserve water. If hydration reaches 0, the character dies. This system would discourage the practice of drinking large amounts of water between periods of willing dehydration.
Energy would represent the caloric content of a food item. Similar to hydration this would be calibrated as 0 meaning a dead character. This could also be uncapped stat, with moderate diminishing returns on uptake for high energy levels, with additional penalties as the character grows fat. Low levels would of course also give debuffs from starvation, yet metabolism would lower to conserve energy.
Satiation is the fullness of the stomach. Both food and drink would have a satiation value partially based on their volume. Drinks moves quickly through the intestines which can be modelled as them having low satiation in comparison to their volume. Satiation would be capped, but would not be hazardous at low levels. Satiation has the role of acting as limiter to food and water intake, and to affect mood. Being hungry is a miserable experience, but is in itself not lethal assuming access to water and calories.
This could further be leveraged by mutations and bionics. A predator gorging on large amounts of meat between longer periods of dormancy? A bionic serving as an artificial camel hump, reducing water loss at high levels of hydration?