I don't know if its micro or not, I still remain open to the idea. For e.g. I have work friends (with similar activity levels to mine) who can eat tons of rice and remain skinny and if I do that I know for a fact that I'm gonna put on 10lbs. Our ethnicities are different, but I don't know if that explains it.

You don't understand that different people will burn different amounts of calories as a base?

I'm not and have never said that if two people eat the same amount, it'll impact them the same.

I said that you need to burn more calories than you consume.

You're claiming variance in basal metabolic rate (for people with similar activity levels/lifestyles) is potentially significant, but also variance in digestive efficiency is negligible?

I don't know if either is false/true, but its interesting to consider. Maybe someone from that domain can shed some light. Happy to look at anything you or others link to.

BMR variance is significant. It's like the core to any weight loss story.

What I'm trying to say is that trying to change your BMR through some diet is a fool's errand. Just figure out your BMR and consume fewer calories than that. It's very very simple (though I won't say it's easy).