not playing the satiety game

Everyone gets satiety wrong in two key ways. It's understandable; we are still being haunted with the 20th Century idea of thinking about eating as a behaviour, and specifically a behaviour to be managed. We have lost any grasp of eating as intuition guided by drives, except when those drives are recognizably broken. We certainly don't think about eating as a dialogue with endocrinology, but it is.

I was listening to the fairly excellent (let's just assume I put all the relevant asterisks on that) Chris van Tulleken talk about the softness of ultra-processed food. His point about softness is that it makes it easier to eat too many calories, with studies showing around 500 kilocalories more energy consumed in meals of food that is soft in the style of ultra-processed food, compared to macronutrient matched controls. Huh.

I went through a period several years ago where I was eating large amounts of heavy cream, butter, and ghee, and wanted to start playing with what it was like to eat saturated fats to excess alongside eating modest amounts of starch, in the form of parsnips in particular, but other slightly starchy vegetables as well.

Now, I have a history with parsnips, and I think there are some ways in which it's hard to eat too much of them, but that was my first real experience of truly overwhelming satiety. I could not eat anything else. The idea of eating felt terrifying. Actually, the idea of existing felt lowkey terrifying. I realized within a single mouthful that I was slightly overeating, and I stopped mid-bite. I had so much energy afterwards that it was vaguely unsettling, and I think I went out and walked like 5km just to stop vibrating out of my body. The kind of thing people who play at being Ray Peat devotees on the Internet talk about.

The starch wasn't necessary for that experience, but it was a good vehicle for the fat. I've repeated that experience with heavy cream or butter any number of times since. I actually don't quite like it. Once I even ate a spoonful of sugar to make some insulin available and to store some of the energy, rather than feeling its incessant availability. I had to find something to take the edge off, and the energy wasn't going away on its own. I can get there with MCT oils, too, but they are hard on my stomach in a way I don't quite get.

Those were some pretty intense experiences of excess energy availability, and they play out the way that it seems like it's supposed to. Massively satiated, restlessly energetic, spontaneous movement, and so on.

As long as I'm in ketosis, aren't I always eating in energy excess, though? I mean, my liver just loves to create new glucose, and I have more than enough stored fat on hand that adequate lipolysis should mean endless energy available in the form of ketones. Would that it were so, but sometimes it's not far off.

Those experiments of eating excess fat gesture at the first real way that our thinking about satiety is wrong, in the sense that van Tulleken is wrong.

You see, van Tulleken thinks that the problem with softness is that chewing drives some satiety mechanisms in the brain, and there is absolutely no chewing involved in my intake of ghee. So it would be for marrow and all other kinds of highly fatty food we evolved with as food. Yet I get disgustingly, upsettingly satiated feeling if I eat one spoonful too much of MCT oil or ghee or fish oil. There are lots of things that converge to give rise to satiety. The most annoying kind of wrongness about this are those family members who have been eating low-fat yoghurt since the 1980s and insist that satiety is about being physically full, and who say that protein reduces food intake. Yikes.

Even there, though, I am playing the satiety game, I am thinking about what changes my behaviour so that I stop eating, and that is so entirely the wrong thing to be thinking about. Whether you feel sated or not doesn't actually matter, and that's where we go so badly wrong.

If I eat 500 extra kilocalories, then I have an excess of energy available. There are a lot of things you can do with an excess, you can be restless, you can move, you can feel like shit because you are inhibited in your ability to move. That energy wants to go somewhere.

If the energy stays available until it can be used, then it doesn't matter that I ate 500 more kilocalories than someone eating some standardized meal would have eaten. I've taken friends to Brazilian steakhouses who wallow with me in the wonders of fatty meat and who then will actually not feel like eating the entire next day. If you start eating meals that are higher in energy, then you should notice either that your level of activity changes, or that your spacing of meals changes. That's not, however, what we see.

I suspect that a small part of that effect is that a lot of people have actually been trained to view and experience eating as a behaviour to be managed, and so they dutifully eat at appointed times. This can emerge more organically, too, in people who are eating for stimulation, entertainment, and self-soothing.

The larger part of the effect, as far as I am concerned, is that we eat energy which is then partitioned off where it cannot be used. Eating 500 more kilocalories does not mean that you have access to that energy continuously during and after digestion. For a lot of us it seems to take a detour into adipose, even into visceral fat.

This happens for probably very many reasons, but we have some inklings that some types of fat, even, might signal the body that they need to be stored, possibly urgently, possibly in the viscera, and are inflammatory if left circulating (and inflammatory when stored.) That's kind of awful, and it's hard not to think of those sorts of things as poisons that should be consumed only if they can be burned right away, and only in the amounts that can be burned right away, much like alcohol. (Alcohol is burned preferentially when present, because it's poisonous to us, and disrupts processing of other energy until it's gone.)

Then there's the carbohydrate-insulin model of obesity, which suggests that like my self-rescue from an overdose on saturated fat with sugar, it's food maintaining a hyperinsulinemic state that keeps us hungry. If you think about a fed-state ketogenic diet as being similar to the fasted state in a good way, then it seems like there are awful diets of ultra-processed food that keep us in the fasted state in a bad way, in the hungry state, in the food-seeking state. This is obviously very profitable if you can sell people food that is mentally satisfying but hormonally hungering, and this is where van Tulleken is right in the big picture, but missing the mark somewhat on signalling.

Eating is a dance with the endocrine system, with dopamine, with all kinds of parts of ourselves that are always going on simultaneously, and that pull various levers, some of which we might call satiety. It is not, though, simply the behaviour we can observe, and the dance does not end when the eating stops. You can overeat at any given point, and if the energy stays available, then there is no reason you should have stopped eating sooner. So, too, you can do pretty well eating energy that cannot be stored very effectively, and just eat all the time, like some sort of hummingbird. The honey diet is very much not for me.

I think we need to stop playing the satiety game, and start wondering more about what happens in the postprandial state. Where does the energy go, and why? Is it usable? Is the body content with the energy that is available to it, or does it need more? Does it, in fact, even have the ability to use that energy? Maybe fat oxidation is broken or inhibited, or maybe the Randle cycle means that only a small portion of it is available for the moment, and it's not the kind of energy we needed. Maybe what we've eaten is even poison, and is not going to feel good or be good when used as a habitual source of energy.

Whatever goes on when the energy starts to be stored and we find ourselves wanting more food at once, and we feel like shit and know that something is missing, it has nothing to do with the movement of our jaw, and nothing to do with whether we achieved satiety in the first place.