Nah, I get it. Not screaming or whatever either. You are correct that human physiology is complicated. There are indeed many factors that go into nutrient absorbsion, etc. However, no one that has stopped eating for a significant amount of time stays fat. Not eating isn't comfortable. The constant dopamine hit of always putting something into your mouth and having your taste buds light up your brain is super addicting. Feeling hunger is uncomfortable. No one denies any of this. But ultimately, it is up to you, what you choose to put into your mouth and what level of activity to perform to expend energy. If you need psychological help and coaching (think life style changes, CBT, etc), I'm 100% in support. But the responsibility for being fat is on the person for the vast majority of the cases. Modern, car-focused society is not very supportive of fitness endeavors. Weaponized food science (high calorie, low nutrient shit designed to addict you) and weaponized psychology (I bet you can sing at least three jingles for some company if you live in the US) is not supportive of healthy diets.

The research and me are both correct. You can have metabolism issues and still be responsible for your fatness. Thermodynamics ultimately decides your fatness. Without a source of surplus calories, you will lose weight, period. If you don't, it is a measurement error or some adjustment in metabolic output estimation needs to be made. And if you've somehow magically measured, perfect, all of your input and output and are still not losing weight, get yourself a Nobel for perpetual motion. You just broke physics.