In terms of losing wait in my view they can work if you stick to their guide. I did feel hungry a lot and a mental challenge at times and that's often when I would have to stop. I found i needed to drink a lot more fluids just to get through a day. I worry about my body getting enough nutrition as well. You need to learn how to eat more healthily overall if you want to keep the wait off. I have been doing this diet on and off for about 3 years. Its useful if you don't want tout much thought in the whole process and the cookies are yummy. I am still undecided about the long term health effects on the body I think the idea of short stints works best. I have been told if you had the energy you could also easily bake your own cookies that you could put more nutrition into but I hate cooking so not going to happen for me. Also I do worry how its affecting my gut and the meal size , and digestion patterns as I have had a number a gut issues over the last 5 years.