Hi! I am on a diet at the moment because I want to lose just under a stone. I weigh 7.2 stone and am 5 ft 4". I exercise all day everyday by running, walking, ab workouts, cardio, aerobics and dance. However every time I lose a lot of weight, I gain it back on through eating carbs and calories. So, I decided to work off more calories than I actually eat. However, this makes me weaker so I need some alternatives that have basically no calories but are still substantial.