calories and fat

what would happen if you had your recommended calorie intake to maintain your weight or whatever but only had half the fat or something
e.g. 2000 calories but only 10-15g fat?
would you lose weight or what?

Reply 1

Barny

You would stay the same weight, calories in vs calories out is what matters.

Cholesterol levels may improve, as may blood pressure and insulin sensitivity, as well as a few other things.

Reply 2

rock_eleven

imasillynarb

calories in vs calories out is what matters.

is basically what I still believe. However on a forum I use someone recently brought up the idea that basically that since fats and especially proteins have many structural roles in the body, for which they are NOT metabolised for energy, and carbs have no such other uses (EDIT - carbs do have a structural role, but far far less than P and F), one could maybe eat more supposed cals in fat than carbs, for example, and maintain weight.

That idea may not work very well the closer you got to a single-macronutrient diet, though. I dont know of any studies where people have been fed on the same number of cals, excluding one or more macronutrients completely.