CICO (calories in calories out) mindset by itself is retarded.
Calories matter only in context of metabolism. It decides whether your food becomes energy or fat.
A “fast metabolism” can come from two completely different drivers:
- Proper thyroid function (the good kind)
- Chronic stress (the degenerative kind)

Under-eating triggers the stress response; your thyroid signals your body to shift into survival mode:
- Cortisol and adrenaline rise
- Thyroid function drops
- Protective hormones like testosterone drop
- Stress hormones including estrogen further rise
- Metabolism turns catabolic, eating lean muscle to survive
- As muscles are metabolically stimulating, the loss in muscle tissue will further slow down metabolism
- A downward spiral of entropy entails…

Congrats, now you can eat even less.
The result is the typical skinny fat physique and pancake ass.

Sugar is stored as glycogen in the muscles and liver. When glycogen runs low, your body will break down muscle to keep blood sugar steady. Detoxification depends on a healthy liver and your liver needs two things which are sugar (glucose) and proper thyroid function.
Rather than sugar being “addictive”, it’s essential. You can hold your breath longer than your brain can go without sugar.

“But muh keto!”

Using fat as primary fuel is a stress adaptation, not a sign of health.
Your body can use fat for fuel but that doesnt mean it should:
- Ketones are made during starvation, not thriving
- Keto mimics famine; in ketosis cortisol rises to maintain blood sugar since there is no glycogen
- Burning fat increases lipolysis which releases PUFA into the blood increasing oxidative stress and suppressing thyroid function

While a ketogenic diet can serve some purposes short term, it is inherently a stress adaptation. Survival mode. Running on fat is like running a car on old motor oil, you can do it, but the engine wears out faster. If you experience cold hands, insomnia, mood swings, losing hair etc. there’s a good chance you’re crashing your metabolism instead of burning just fat.

Severely restricting calories and sugar will eventually lead to chronic stress, thyroid suppression and a slower metabolism. Eventually you gain fat eating less. The classic yo-yo spiral. I am calling it fat-gain instead of weight-gain. Because weight-gain would be a good thing in the context of gaining muscle.

The bottom line is that it’s not just about eating less and exercising more, nor calories in calories out. It’s about nourishing your body with what it needs to function so that it can maintain and even evolve its current structure — Fat loss as a side effect of vitality.