I am 10 over weight and have joined a Gym. I order to Is Xenical effective only SOS basis. I normally take very low fat low carbs diet most of the time except on weekends when I go out for dinner or partying. To avoid jeopardising my Gym results , Can i take xenical only 2-3 times a week only when I take heavy and fatty meals? Does xenical work dose to dose basis or ceratin amount of regularly taking also works?