Sunday, January 6, 2013

Book Review: Perfect Health Diet

The new edition of Perfect Health Diet was released in December 2012 and the Australian edition is set to be released on the 7th of January.  Australian readers will appreciate the Australian edition as the measurements are in metric* and it has Australian statistics where possible. 

* The exception is the blood test measurement for vitamin D.  For vitamin D, to convert ng/ml to nmol/l, you will need to multiply by 2.5
 
Perfect Health Diet

For those unfamiliar with the previous edition, Perfect Health Diet (PHD) is about finding a diet for perfect health (fancy that).  Often you’ll hear you should ‘eat a healthy diet’.  But what is a healthy diet?  Simply recommending real food (or whole/unprocessed food) is ok, but carnivore and vegan diets can qualify as real food and some real food can be nutrient poor and/or toxin rich.  Most people have some vague ideas as to what a healthy diet is, which probably doesn’t come from synthesising research studies.  That’s where Paul and Shou-Ching Jaminet come in with PHD.  Similar to the previous edition, PHD is divided into five sections: 

  • Part 1 begins with a big picture perspective - looking to hunter-gatherer diets, other mammalian diets, human breast milk and body composition for clues.
  • Part 2 covers the macronutrients, the types of fats and carbohydrates, ideal protein, fat, carbohydrate intakes and macronutrient ratios
  • The Jaminets have come to the conclusion that chronic disease is largely caused by toxins, malnutrition and chronic infections.  Parts 3, 4 and 5 cover these topics

When I read the first edition about a year ago, I was quite sceptical of infectious causes of aging and disease were as prevalent as what the Jaminets were saying.  Over the course of 2012, I looked into the causes of chronic disease and found chronic bacterial and viral infections are quite widespread, are associated with many chronic diseases and seem to have a strong role in autoimmune diseases, depression and cancer.

To clear chronic infections the Jaminets primarily recommend measures to strengthen the immune system such as an 8 hour eating window to promote autophagy and vitamins A, D and K2.  One thing I noticed in my research is that while many people have chronic infections, those with a weak or poorly regulated immune system were the ones who were far more likely to develop chronic diseases from them.  So even if the measures in PHD don’t rid you of a chronic infection you will be far less likely to develop a chronic disease.

The New Edition

For those who have read the previous edition you’re probably wondering what’s different with the new edition.  It’s a longer book (~1.5x as many pages) with more content.  The recommendations have changed a little and there are new sections on weight loss, blood lipids and how to be in tune with our circadian rhythm.  Paul Jaminet has a two part series on what’s new in the new edition.

Weight Loss

In the weight loss section the Jaminets discuss the food reward hypothesis of obesity, which has been a hot topic in the blogosphere over the past two years.  They make the following points:

  • The cafeteria diet and the refined ‘high fat diet’, which are fed to rats and mice to induce obesity, are very palatable and rewarding yet also nutrient poor and toxin rich
  • Nutrient hunger is a plausible and logical explanation for overeating nutrient poor junk food and obesity
  • Obesity is a chronic disease.  We should be able to lose weight/maintain a healthy body weight by addressing the same things that underpin other chronic diseases - toxins, malnutrition and infections
  • ‘A healthy diet is a delicious and satisfying diet’ and ‘every meal should be delicious’ 

I agree with all these points and the last point is particularly important in a diet related book.  You wouldn’t want someone to eat some strawberries (for example) or a delicious meal, then feel guilty and anticipate weight gain just because they were delicious.

Reader Reports

Another new feature of the new edition are ‘reader reports’ - testimonials of readers from the blog who have experienced health improvements from eating a PHD style diet.  While testimonials are hardly gold standard scientific research, some of the reader reports in PHD are of people overcoming chronic health problems, which should be quite intriguing and motivating for someone new to all this.  After all, it was one of the things that first got me interested in nutrition and health.

Some of the reader reports are about the benefits of ketogenic diets, some are about coming out of very low carb diets by adding starches and a few are about lowering the number of carbohydrates from the standard australian/american diet (SAD).  I hope no one is confused about this, as it’s consistent with the overarching economical approach to nutrition in the book - be sufficient in every nutrient (including glucose) without excesses in any nutrient, while minimising toxins.  There seems to be two target audiences for PHD: people following a low carb or paleo diet and people eating the SAD or something similar.

Summary

At the moment PHD is the best book I've read on the subject of diet/health and is the book I would recommend to people interested in weight loss or in improving their health.  There is much to commend the book:

  • PHD is a well-researched book with more than 1,000 citations.  The scientific approach and the citations should be convincing to a sceptic and an excellent introduction for someone who wants to learn more
  • Even though PHD is scientific, the science is not impossibly academic and should be understood by the average person (although it may take a little longer to read or require a second read).  The layout makes the book really easy to read
  • The Jaminets approach the subject of nutrition in quite a unique way (such as breast milk, mammalian diets, the economical approach to nutrition, chronic infections, etc) and the arguments are often logical and intuitive as well as being supported by evidence
  • PHD covers a very broad topic yet manages to be thorough and quite specific in its recommendations
  • The economical approach to nutrition in the book makes it safe and easy to recommend to a wide audience.
  • A comment by George on Chris Kresser’s site described PHD as an ‘idiot-proof diet’.  Which I agree with, due to the specific recommendations and the safe economical approach to nutrition
  • On topics such as saturated fat, salt, etc, instead of going with political correctness or stirring up a controversy, the Jaminets just say it how it is
  • Recommending 1.35kg of plant food per day dispels the popular misconception that Paleo diets are all about eating meat 

I have a few minor problems with the book:

  • 75g of protein a day might be too low as a general recommendation.  Robb Wolf recommends 2.2g of protein per kilo of (lean) body weight, and other people recommend 1.4-1.5g per kilo of ideal body weight and a minimum of 90g.  Eating more protein would also improve nutrition if it comes from meats, eggs and other whole foods
  • White rice is a safe starch but not very nutritious.  People who are eating more calories can probably get away with more white rice, but those who eat <2,000 calories a day should eat less (perhaps <1-2% total calories per week).
  • The supplement recommendations could be more convincing.  Unlike the SAD, people eating a PHD should be getting enough selenium, B vitamins, vitamin C, zinc, copper and choline, etc.  Also, the trace mineral list at the end of the chapter had very little research to support the recommendations 

Rather than say you should or shouldn’t buy PHD I’ll say this: if you had to pick only one diet/health related book for yourself or for someone you know, Perfect Health Diet would be that book. 

You buy the book from Scribe here 

* Paul Jaminet sent me a review copy.  I had the previous edition and was planning to buy the new edition anyway.  I was already recommending the previous edition to those who were interested and now will recommend the new edition.  I won’t receive any money from this review

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