The book cites somewhere between 20 and 100 peer reviewed scientific papers, maybe those pages aren't available in the preview you were able to find.

I can't find the exact part of the book where he mentions the guy who ate 500 cal/day and didn't lose weight, but when I find it again I'll note it. This person did have serious hormonal issues, though. Most people of course, 500 cal a day and also exercise weight will come off, how permanently is another question.