I like this analysis a lot. This is the kind of applied rationality stuff and "epistemics for modeling mundane stuff better" that I'd like to see much more of on LessWrong.
I enjoyed this post.
I'm interested in interpersonal variation on these issues. Some people feel very strong "hangry" emotions and even physical pain, whereas some people (like myself) feel almost no negative emotions or sensations when they don't eat for prolonged periods.
But some people have an insatiable appetite, and when they start eating, they can't stop. If there's limitless food of the right type available, I can easily put away 2000+ calories in a meal.
I wonder if these are anti-correlated in an interesting way. It seems that there could be an evolutionary logic that we need signals to eat, but these work through fairly distinct pathways, leading to subtly different "hunger phenotypes".
Yeah, I've found it interesting to compare myself to people like exfatloss (who naturally has an endless appetite), and to compare across diets. I've done the Croissant Diet, where I never felt full and learned that not feeling full is fine, and the potato diet where I always felt full and sometimes had an appetite even after eating, but also felt great mood-wise.
I'm currently taking retatrutide (a GLP-1 drug) and it has the weird effect of basically destroying my appetite entirely while still experiencing (weak) hunger pangs, so I know at an intellectual level that hunger pangs mean I need to eat something, but I don't have the drive to eat at all. I plan to write a longer post about this once I have more data.
exfatloss recently wrote about the difference between being satiated and being full, and not experiencing satiety until their 30's. Thinking about this made me realize that there's at least four axes of hunger (pangs, appetite, fullness and emotional state), and some interesting edge cases. These hunger feelings are correlated, but don't always occur together, and sometimes they even point in opposite directions.
Having shared terminology to discuss this might help prevent people talking past each other when discussing hunger.
The Axes
Hunger Pangs
There's a physical feeling of pain near my stomach that occurs when I'm hungry. This usually comes on at my normal meal times and sometimes goes away on its own, even if I don't eat.
Appetite
There's a feeling of needing to eat. I think the opposite of this is what exfatloss calls satiety. I associate this with binge eating and Pringles.
Fullness
Fullness is what it sounds like—sometimes it feels like my stomach is physically full. Weirdly, this one is backwards from the others, and fullness or bloating feels bad, although it can 'take the edge off' if I have other hunger feelings.
Emotional State
I'm not sure if it makes sense to call this one axis or many, but when hungry I can experience things like:
Weird edge cases
The "standard" form of hungry is that your stomach is empty, you experience hunger pangs, you feel a need to eat, and you feel tired and angry. The more interesting cases (to me) are when these signals don't match, or where they point in different directions.
Hanger
Let's go right back to being hangry. The prototypical example is someone who's unreasonably angry, and then they notice that they need to eat something because they're actually hungry.
The weird thing here is, how would you not notice the hunger pangs and desire to eat? I propose that many hangry people are not experiencing the other aspects of hunger.
Rice Diet Fullness and Heavy Cream Emptiness
When eating low-calorie-density foods like rice, potatoes and fruit, it's common to feel uncomfortably full while still having an appetite and wanting to eat more. In my experience, I don't experience hunger pangs in this situation. I'm not sure how it impacts emotional state.
On the other side, exfatloss describes their heavy cream diet as extremely satiating but not filling.
Hard Exercise
When doing hard exercise, my body wants sugar, and consuming it improves my motivation. The weird thing is that I don't get hunger pangs or an appetite. I mostly just want water and find that I feel better if I put sugar in that water.
Around an hour after I stop exercising, I experience a strong appetite and sometimes hunger pangs.
Going to Sleep Hungry
I'm not sure how common of an experience this is, but I try to stop eating by 5 pm because I sleep better. Most days, I don't experience any discomfort from this, but sometimes I do experience mild hunger pangs. The weird thing is that I don't feel much of an appetite (it's easy to just ignore the hunger pangs). I don't think this affects my emotional state.
Strangely, if I start eating at this point ("just a snack"), this very rapidly causes the mild hunger pangs to go away, but replaces them with a much stronger appetite.
Putting It All Together
I'm not sure if this is all of the axes (or if my experiences with them are universal), but hopefully this is helpful. I think when discussing diets and hunger, keeping in mind which type of hunger (or tabooing the word "hunger") might make the conversations more productive.
Is this why semaglutide gives people more willpower? They're just not hungry constantly?