Healthy eating is certainly a part of a healthy lifestyle, just as is exercise.
Concern with weight both for health and for aesthetic reasons is a huge part of our culture.
The annual revenue of the US weight loss industry, including diet books, as well as plans, drugs and surgeries is around 20 billion dollars. With so much money at play it is not surprising that there are a lot of diet plans, and a lot of diet books.
A great many fitness professionals prefer to promote general healthy eating over specific ‘diets’.
US News did a comparison of diet plans recently and the one that came up as ‘best’ is the old standard DASH. Here is a link, if you are interested http://health.usnews.com/best-diet/dash-diet?int=9ff509
I know nothing about this person you mention except that I have heard he is on TV (I do not have TV). I do not read most diet books. I have not read this one, and therefore can only make general comments on my feelings on diet books, rather than anything on this book in particular. It may be wonderful, or not. There are just other ways I prefer to spend my money. I did read and enjoy the book on the South Beach diet. I found quite a lot of it rather interesting, though there were parts I just skipped. A family member wanted to do it, so I did it with them and we did loose weight, but found, as is really quite often the case, that it is hard to maintain over time. I also really like Michael Pollan’s books, because they make you think. They are about the context of food, rather than just about its consumption, or focusing on not consuming.
For myself I think what is most helpful is the guidance of a good nutritionist…. particularly one who never sells supplements, nor profits from sending you to buy them from someone else. Going to a nutritionist means you will get help in the process that will be uniquely set for what you need. A licensed nutritionist (someone with a great deal of training and who has passed a licensure requirement of the state) can get you started, and you may find it helpful to continue working with one for a while, or to use a wellness/health coach that can provide more general guidance in multiple areas, though not as specific as the nutritionist.