The complete title is The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman by Timothy Ferriss.
Please note that the author does NOT have any intials behind his name. He is not a doctor and makes no claims to being a medical professional. What he does claim is that he has regular contact with sports people and coaches of all kinds. These people, probably more so than doctors, are on the cutting edge of what works.
If you want to lose some weight, if you want to gain some muscle, if you want to increase your energy levels, this book will give you several ideas. Some of the ideas will sound familiar, like vegetables and lean protein are good for weight loss. Others might surprise you, like taking a cold shower will help you lose weight because the body has to work harder to get its temperature back up.
If you want some new ideas, this might be the book that will help you find a different way to get where you are going.