Changing diet, need some help

zoidamite

Since you are doing medifast, your body is in ketosis. With that said yes you are only eating 1000 calories, but if you have body fat, that is where your other calories and energy are coming from. If you decide to continue eating that way (low fat, low carb) , you will eventually want to increase your healthy fat intake, because once you begin burning that fat, and there is nothing left, you will begin burning muscle as energy. That's the reason for increasing the fat intake. You can find more info by typing muscle mass and low carb diets in Google. I did Insanity and P90x on a low carb diet, and it was medifast. So from personal experience you will be fine. But you must make sure to increase your healthy fats once you begin shedding too much fat, otherwise you will most likely lose muscle.