If you're a fitness freak or on a stable weight you are happy with, find another book. This one isn't for you. Ditto if you are looking for super fast weight gain or have a penchant for fad diets. Ditto if you are looking for a full-on gung-ho weights program.
BUT!
If you are struggling to lose weight, have ever lost weight and bounced back up again, are happy with your weight but not your shape, have tried all the diets, or even haven't tried them, or don't know where to start - then this is the book for you.... regardless of age (or even gender!).
Dr Nelson's book focuses on strength training as a fundamental element of healthy weight loss, particularly for its role in maintaining bone density (and toning!) - as opposed to the diet/aerobic exercise route which can lead to loss of bone density and/or loss of muscle (rather than fat). That said, she also covers the role of good nutrition (focusing on the long term, not the faddish) and aerobic exercise.
The result is not "dieting" as such, but healthier living. If you want to lose 30lbs in 3 months this isn't the book to read - but if you want to lose 30lbs steadily and KEEP IT OFF, then dive in. Generally I would say the focus is on inches, tone and well-being rather than pounds anyway.
The discussion of studies, science etc could have been heavy, but wasn't - it was very readable and even extremely motivating. It meant everything in the book made sense, which for me, made it easier to take on the recommendations of this book as a lifestyle not a fad.
The exercises are very easy, but if you are just starting out, that's not a bad thing - better than throwing you in with stuff you can't do, and they will give you plenty to build on. This book will give you a great, balanced foundation to a healthier lifestyle.
There's plenty of checks along the way to keep you on track and getting results - have you chosen a good goal weight (and do you need one?), are you working out at the right intensity, are you eating well, are there warning signs that you are coming off the rails?
You're also supported with checks to track your exercise and eating - backed by research showing that those who keep track, stay on track and get better results.