please explain...

dydn11402

so ive been reading a lot on here about BMR, TDEE, etc and how weight loss is basically calories in vs calories out.

im curious though how other factors come into play. what about genetics? faster/slower matabolism? hormonal issues?.. etc.

you can have two people of same height and weight eating the same things and one will lose weight (or more weight) than the other. it seems to be much more difficult for some people to lose weight than others. and some people are naturally skinny doing no exercise and eating whatever they want while others eat well and exercise but are still fat.

can someone explain to me (if it were as simple as calories in vs calories out) why this is?

GODfidence

Genetics.
Some people simply have metabolisms that work more efficiently.

Ed98043

...and that's why online TDEE estimators are just a ballpark figure. Each of us is an individual and there's usually experimentation involved in trying to find the calorie level that works best for our goals.

As for efficient metabolisms, maybe one like mine that very efficiently converts food into fat, and holds onto that fat come hell or high water, is the superior metabolism from an evolutionary angle. My people could survive longer in a famine, long after those skinny fat-burners were already in the ground. Unfortunately it's just not a great skill to have in this day and age.

dydn11402

so basically somebody with a slow metabolism is burning fewer calories. that makes sense. except when he puts his info into the TDEE calculator , it has no way of knowing this info so he is really not getting an accurate count. in fact, probably noone is getting an accurate count. why do people take this TDEE number as the be all end of all weight loss then?