4 stars because its a very good program and I'm very glad that this book was all I needed in enable to be able to take the program. I'm also glad that CLEAN gives you options to take the program without buying supplements from the company, as well as the option to buy supplements so supports those who may not want to invest a lot of money buying supplements and shakes or for those who simple prefer to use fresh local produce and make their own smoothies and soups at home.
I did not assign it 5 stars because there were the following disappointments:
1) There is not much explanation of the science behind why
2) There are some items are remain ambiguous. For example, its unclear if you can eat sweet potato whilst you are on the clean diet.
3) There is not much support in terms of the emotional and physical sensations you might feel and why that is. For example, if you experience lots of headaches during the program why is that?
4) The narrative style of the book makes it difficult to look up information quickly. I would put tables of what you can and can't eat at the back so this can be quickly referenced, for example.
Regardless, I would recommend this group and I would hope that a more user-friendly book is created in the future, or even a short video.