WarVader
Athina,
I would answer that by saying you can do both, depending on your current health and the goal you have in mind. The warrior diet allows both because the planning (once you get used to listening to your body's needs) is easier to follow. Losing weight and gaining muscle is slower, I will allow that caveat, I would also counter that what you gain or lose will be of better quality. I went from 150 to 230 lbs in 7 years (as was my intention) on the warrior diet but I did stagger the amount I ate on certain days, as well as what I ate, and it allowed me to keep my body fat down. As with any way you eat, supplementation is very important, if only to make sure you are not missing any nutrients. The "lynchpin" to all of this is your activity level...at the very least, walk and if you can weight train, all the better.
Good luck
WarVader