There are a lot of good weight loss books out there, but you're not going to find them in an unreviewed $2.99, 5 page, kindle book.
If it weren't for reading a great deal of books and articles on weight loss, I would still be trying to lose weight by the old-fashioned "just diet and exercise" ways I tried at and failed for 30 years.
For example, some of the books that I learned a lot from (though even then there are some problems in many of these books - none of them are perfect): The End of Overeating, Volumetrics, Neanderthin, The Primal Blueprint (which I have a few qualms with), Refuse to Regain, Exchanges for All Ocasions - and many other books detailing exchange plan dieting, The Low-Carb Bible, Living the Low-carb Life (new edition is called Living Low-carb), The South Beach Diet, The Zone (and other Zone books by the same author).
We have to use the same level of judgement for weight loss products, that we use for other serious decisions in our life. You've got to check the credentials, and avoid scams - and one of the biggest red flags for a scam is the "too-good-to-be-true test."
Because anyone can sell a book on amazon - read and evaluate the reviews (and also apply the "too-good-to-be test.") Authors can pay people to write good reviews - so read the bad reviews first. If there are none, especially if there are only a couple reviews, be suspicious.
Check out the author - see what other people are saying about the book.
You probably wouldn't buy meat from a dirty grocery store, a computer from a door-to-door salesman, or choose to go for cosmetic surgery from a "doctor" who operated out of a hotel room.
Weight loss is difficult and complicated, and even dangerous if done unsafely so you have to be careful where you get your information and your products. If you wanted to learn how to fly a plane, you wouldn't buy or trust a 5 page manual written by someone who you couldn't even verify had ever been on a plane, let alone knew how to fly one.
I'm not trying to pick on you. It's hard to be an informed consumer, but it's not hard to become one. There's just a learning curve involved, and you need to learn to spot the scams and how to evaluate the information you read to determine whether it's worth taking seriously.