I have been reading some of his blog articles, and then I joined the Facebook Group, and this man has some really great information about how obesity works in our body, and the huge part that insulin and insulin resistance plays in making people gain weight.
The ebook is almost $10, and I usually do not spend that much on ebooks; but I really wanted to read this whole book, and more than the little parts that he discusses on the website.

It is very interesting, and Dr. Fung does a great job of explaining something in laymanís terms, while yet giving a complete explanation of how something works in the body.
I am about 1/3 of the way through the book, and I definitely recommend buying the book, or at least, checking out some of the information on his website.
He totally recommends low-carb/keto, as well as fasting to not only lose weight, but to help completely detox and heal your body.

Here is one review of his book, and it really gives you a good overview of the basic premise of this book.

http://www.diagnosisdiet.com/obesity-code/