Reasons to be skeptical

I recently came across a book, Joshi's Holistic Detox: 21 days to a healthier slimmer you - for life by Nish Joshi. I am going to use this book as an example of things that should make you skeptical.

Notice that this is a book about diet and nutrition. As such, this is on a subject which there is copious amounts of serious research on. It is, quite simply, a subject we as humans can readily investigate using well established research techniques. Why is this important? Because this is a field in which it is possible to have expertise.

So, of course, the first question is this: Does the author have any expertise in the field he is writing about? Some quick points about this: in various countries, only particular terms are regulated. The title "Registered Dietitian" are protected titles in Canada and the US, meaning that you are only allowed to use the RD title if you actually have the qualifications for it (meaning you must have received an education from a registered college) - just like you can only call yourself an MD if you have gone through medical school. The term nutritionist, on the other hand, is not regulated in many of the provinces in Canada. This means calling yourself a nutritionist is meaningless in the provinces it is unregulated - I could legally pronounce my dog to be a nutritionist. He is unlikely to ever become an RD, though, as he lacks the capacity to read or write.

So, the first test of this book: Does the author have the qualifications relevant to the subject matter? The answer is, I sure don't think so. The only qualifications which the book suggests that the author has is that he has designed some diets which some celebrities have followed. This is probably the biggest reason to be skeptical of a book like this - it is possible to have professional training in this field, and the author simply lacks it. It is possible that he is a wonderful self-taught nutrition guru, but the fact that he has made no effort in getting registered qualifications of this is worrying.

Second test: Do any of the people who endorse this book have the relevant qualifications? Even if the author does have qualifications, if the only people that have anything positive to say about the book are unqualified, it may mean that the author has a very fringe position in the field. On the back of Joshi's book, there are 2 positive comments from actors (Patsy Kensit and Sadie Frost) and then positive comments from popular magazines. Again, Joshi fails this test.

Now, for some general comments on the content of the book: a quick flip to the back shows that it endorses various sorts of quackery: Acupuncture, allergy elimination, etc. On page 21, he suggests his readers drink 2 litres of water a day (this is 8 cups). This is a common misconception, we do not need this much water intake. The entire book is full of huge claims about toxins in our bodies and that doing various things will flush them out, that the water we drink is full of chemicals, yet there are no citations for any of it.

Now, the book does advise some obviously good things - cutting out junk food, drinking less alcohol, avoiding packaged meals, etc. It is hard to fault this sort of advice, and it certainly isn't the case that everything in the book is untrue. However, we have been given no reason to accept the authority of the author, and so the fact that a claim appears in this book lends it no more weight than it already had on its own.