Yep, that's leptin resistance for you. Obesity is really a hormonal condition, and this is why GLP-1 inhibitors are so effective - they actually treat the hormonal condition and allow the recipient to manage their food intake without having their body hormonally work against them.
A layman's explanation (to be clear, I am the layman) of my best understanding of the subject:
Hunger is controlled by 2 hormones:
- Ghrelin, which causes hunger and is produced by the stomach
- Leptin, which suppresses hunger and is produced by fat cells
As fat cells accumulate, leptin levels also increase, but a person that has developed leptin resistance will not feel the appropriate amount of hunger suppression from the leptin, leading to chronic hunger unless large energy intake is sustained.
This is true. They do not think, because they are next token predictors, not brains.
Having this in mind, you can still harness a few usable properties from them. Nothing like the kind of hype the techbros and VCs imagine, but a few moderately beneficial use-cases exist.