Friday, January 13, 2017

Book Review: Dr. Gundry's Diet Evolution


Next up for review is Dr. Gundry’s Diet Evolution. The author, Dr. Stephen Gundry, is a heart surgeon who has pioneered the development of several surgical devices and techniques. He is a very accomplished physician.

Introduction
This interesting book presents a weight loss strategy based on an understanding of how our genes work. Dr. Gundry believes that over many thousands of years, our genes have developed defense mechanisms that are now working against us when it comes to our weight and our health. His theory is that by adopting certain dietary and lifestyle habits, we can make these genes work for us instead of against us, resulting in weight loss and improved health. The book is 304 pages long. It is well written and I enjoyed reading it.

5 Things I Really Liked About Diet Evolution
1) It strictly limits sugar and refined carbohydrates like white bread, white rice and pasta. In my opinion, limiting these foods and stabilizing your blood sugar are pivotal to improving your weight and your health.

2) It allows cheat meals. This is a huge part of my recommendations as well. I find regular cheat meals to be essential for several reasons: 1) You don’t have to be perfect to get really good results. 2) The idea of never having a piece of bread, a slice of pizza or a burger again in your life is not at all realistic. 3) Sometimes it is just fun and appropriate to eat junk food. If I am at a Jets or Islanders game, it just does not feel right to be eating a salad or a bowl of black beans.

3) I really like how Dr. Gundry promotes slow and steady weight loss. A huge problem with most weight loss books is that they promise a ridiculous, unsustainable rate of weight loss. A pound a week is what you are looking for. It may not be fast, but it is sustainable and realistic. It is also my opinion that losing weight slowly gives you a much better chance of keeping it off.

4) I like that Dr. Gundry recommends resistance training for weight loss. It is always surprising to me how many weight loss books do not include this essential component.

5) The book contains a large number of well put together recipes.

5 Things I Didn’t Agree With In Diet Evolution
1) This book has a lot of restrictions on what I consider to be very healthy foods. For example, all of the following are considered “Unfriendly” foods and are restricted to some degree: carrots, peas, sweet potatoes, squash, mangos, pineapple, pears, legumes, oatmeal, quinoa, etc. These are all healthy foods I recommend to my clients and I’m not quite sure why they are considered so bad for you on this program.

2) Diet Evolution makes a number of claims that are not supported by the research literature: Here is a small sample:

Eating legumes will slow the rate of weight loss.

Eating whole grains will slow the rate of weight loss.

Milk causes cancer.

Low fat diets have shown to be the most successful for weight loss.

3) The book spends a good amount of time explaining why non-nutritive sweeteners are to be avoided, but includes them in a very large percentage of the recipes.

4) I was really surprised that Dr. Gundry dispels all prospective cohort studies as “silly observations”. I understand that only randomized trials can prove cause and effect. However, they have some very serious limitations when it comes to diet and lifestyle research. For example, ethical issues, short length of follow-up, high drop out rates and low compliance plague most trials concerning our diet and lifestyle. 

In most cases of lifestyle research, longer term cohort studies will give us our best chance of answering our research question. Here is an example; there has never been a single randomized trial to test if cigarette smoking causes lung cancer. Ethical considerations rightfully prevent any such trial from being conducted. However, observational research has consistently shown that smoking causes lung cancer. This is not a silly observation to me! I also found it ironic that later in the book, when discussing the benefits of moderate alcohol consumption, Gundry backs up his claim by citing a reference on alcohol consumption and risk of coronary heart disease in the Health Professional Follow-up study, which happens to be a prospective cohort study.

5) This book is very heavy on vitamin and mineral supplementation. In my opinion, the research has not shown such supplementation to be beneficial and in some cases, it can even cause harm. It never makes sense to me when a dietary program strips a lot of healthy foods out of the diet (such as fruits, legumes, whole grains, etc) and then suggests vitamin and mineral supplementation to fill in the nutritional gaps. Why not just leave the nutrient packed foods in the diet? To me, any diet that we need to supplement with pills to balance our nutrient needs is not a natural diet for humans to consume.

Is Diet Evolution Worth Reading?
Absolutely. This book gets a lot right and the theory of how our genes impact our food choices is a unique take and quite interesting. I would just ease the restrictions on what I consider to be healthy foods such as fruits, vegetables, legumes, whole grains, lean sources of protein and healthy fats.

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