Diet books and supplements cannot guarantee long-term success. For starters everyone is different and what might work for one person might not work for another. Diet books tend to be a mixture of personal opinion and healthcare facts and it's difficult to know what to completely trust. Most of the books and supplements tend to be based on current trends also and many have turned out to be inefficient.
If you eat less when you are in weight training, you will loose weight because you burn more calories in training then not. If you're calorie intake remains the same, you will burn more and lose more body fat.
Honestly, I'm not positive myself. All I can say is that overworking your joints without enough cool-down time will put you at high risk for arthritis.
