Routine and CICO don't mean shit if you've got chronically elevated stress hormones that cause you to eat your own muscle and store all food as fat.
I was on a month long plateau which I broke by stopping all intense cardio and lowering my protein intake For some people, it's all down to hormones.
"Broken metabolism" sounds like a crock, but I could buy "hormonal imbalances".
"I think the basic anti-aging diet is also the best diet for prevention and treatment of diabetes, scleroderma, and the various "connective tissue diseases." This would emphasize high protein, low unsaturated fats, low iron, and high antioxidant consumption, with a moderate or low starch consumption.
In practice, this means that a major part of the diet should be milk, cheese, eggs, shellfish, fruits and coconut oil, with vitamin E and salt as the safest supplements."
- Ray Peat