Doing P90X and not following nutrition plan?

It is possible to cut weight without being on a nutrition plan. You just need to burn that many more calories per workout. Try eating at least 4 times a day but smaller meals. If you don't follow the diet plan you wont cut up as fast as if you did, but you will still get results. Also it depends how quickly you want to get to 190. Following a nutrition plan will always increase the speed of results. If you can't follow every part to a "T" try to incorporate some of the things into your diet, like watching calories, drinking lots of water, and try not to eat something with a lot of carbs prior to bed. Some people say this is a myth but it's true. Carbs are meant to be burned off as energy. If you're sleeping you're body isn't going to use all the carbs and will end up storing the leftovers as fat. Hope this helps, good luck!