[Evgeny]

Different people have different metabolisms too, turning food into energy to be spent, or locking it away instantly as fat -- makes a huge difference

This is not true - at least the "huge" part.

https://examine.com/nutrition/does-metabolism-vary-between-t...

"Metabolic rate does vary, and technically there could be large variance. However, statistically speaking it is unlikely the variance would apply to you. The majority of the population exists in a range of 200-300kcal from each other and do not possess hugely different metabolic rates."

Calories-In-Calories-Out is a rather limited view of the situation.

https://examine.com/nutrition/what-should-i-eat-for-weight-l...

"In conclusion, losing weight requires a negative energy balance, which can be obtained by eating less, as we have seen, but also by exercising more."

[tux1968]

It's like saying, driving a car requires a neutral energy balance, you need to put in just as much gas as you burn.

While 100% true. It's not helpful information. It doesn't mention the fact that different cars burn fuel at a different rate. That some drivers can afford a higher octane fuel. And that a poorly tuned vehicle with incorrect tire pressure will require more fuel.

The point is, that there are many factors that go into weight gain and loss. And while in terms of basic physics it does indeed boil down to energy balance, that ignores a great many factors that affect both ones internal demand for more energy and ones ability to make use of ingested energy rather than turning it into fat.

[JoeAltmaier]

And yet for each of us, where we're at right now, we lose weight by eating less and exercising more that we are right now. Its a wonderfully self-calibrating system.