If u want to loose weight and loveeee non veg, then its gonna b tough job for u. Mutton contains high colestrol. Chicken contains some chemical that may swell u up n fish contains murcury. but it has more advantages except mutton or any other red meat. All u have to be sure is to cook them properly using less spices n oil.
If we take in limited no worries . Mutton will take more time to digest then chicken and fish. Taking more may put on your cholesterol as it contain fat and for making those we add so many masala which is not good . It has to be properly cleaned and cooked .