I would just stick with your limited caloric intake diet; trying to lose weight and learn a wholly new way of eating could be stressful to you and your system. Yes, a lot of people eat too much red meat but it can be easy to cut back some, anything we eat too much of can be unhealthy -- ever eaten a couple pounds of grapes in one sitting? There are overweight vegetarians too.

If you want to up your metabolism some, get more activity/exercise in; that's what it is for.