Correct, The one way to lose weight and one way only and that is a calorie deficit. All other diets fabs only work if you are in a deficit. Some diets may also effect your metabolism changing how much you body burns. But at the end of the day you must burn more calories than you consume to lose weight. The best diet is the one you can stick with long term. You muscles burn glycogen when you do weight training carbs are your best fuel for this or else your body breaks down muscle tissue for glycogen not fat tissue, best way to burn fat is low intensity like walking or light jog.