What presumption! The author doesn't know how useful I find Goodhart's Law!

Seriously though, Goodhart's Law means that the world is more complex in a way that you may not have realized. Saying it is wrong, and that the world is more complex than you may have realized is just expanding it.

Every model is wrong, some models are useful after all.

> "Well, let’s think about the weight control example. Losing weight is a process with two well known inputs: calories in (what you eat), and calories out (what you burn through exercise). This means that the primary difficulty of hitting a weight loss goal is to figure out how your body responds to different types of exercise or different types of foods, and how these new habits might fit into your daily life (this assumes you’re disciplined enough to stick to those habits in the first place, which, well, you know)."

Oh the irony! If you want to lose fat and keep it off, you need to understand and address HUNGER[0]. Just because you understand part of the system, doesn't mean you understand the whole system.

If one part of the process or system is obvious and easy to measure, we will measure it and talk about it. Thus we talk about weight and BMI, not Body Fat Percent and Lean Mass. We talk about calories and measuring food intake and not the body system that drives us to maintain our energy reserves.

Hunger is hard to understand, impossible to measure, and impossible to compare between people at scale. Calories are relatively easy to measure, but they are only INPUTS to the system, not an understanding of the system.

0. Basically every obese person has lost a significant amount of weight at least once in their life. Losing weight is not a mystery. Book recommendations:

guyenet hungry brain https://www.amazon.com/Hungry-Brain-Outsmarting-Instincts-Ov...

pontzer burn https://www.amazon.com/Burn-Research-Really-Calories-Healthy...

You could read one of the book reviews: https://researchblog.duke.edu/2021/03/24/duke-researcher-bus...

Still not great as a tl;dr though.

Maybe the book summary on Amazon: https://www.amazon.com/Burn-Research-Really-Calories-Healthy...