Diabetic Mediterranean Diet

Here’s my  review of good Calories, Bad Calories: Challenging the Conventional Wisdom on Diet, Weight Control, and Disease, by Gary Taubes, 2007.  I give it five stars on Amazon.com’s five-star system (“I love it”).

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This brilliant book deserves much wider currency among physicians, dietitians, nutritionists, and obesity researchers.  The epidemic of overweight and obesity over the last 30 years should make us question the reigning theories of obesity treatment and prevention.  Taubes questioned those theories and pursued answers wherever the evidence led.  He shares in GCBC his eye-opening, even radical, well-reasoned findings. 

Ultimately, this tome is an indictment of the reigning scientific community and public nutrition policy-makers of the last four decades.  That explains why, twoyears after publication, this serious, scholarly work has not been reviewed by the New England Journal of Medicine, the Journal of the American Medical Association, the American Journal of Clinical Nutrition , and the Journal of the American Dietetic Association (as of August, 2009).

In Part 1, Taubes examines the scientific evidence for what he calls the fat-cholesterol hypothesis.  More commonly known as the diet-heart hypothesis, it’s the idea that dietary fat (especially saturated fat) and cholesterol clog heart arteries, causing heart attacks.  Taubes finds the evidence unconvincing.  He’s probably right.

Part 2, The Carbohydrate Hypothesis, revives and older theory from the mid-twentieth cenury that is elsewhere called the Cleave-Yudkin carbohydrate theory of dental and chronic systemic disease.  In the carbohydrate theory,  high intake of sugary foods, starches, and refined carbhohyrates leads first to dental disease (cavities, gum inflammation, periodontal disease) then, later, to obesity and type 2 diabetes, coronary heart disease, perhaps even cancer and Alzheimer’s Disease.  These are, collectively, the “diseases of civilization.”

Part 3 tackles obesity and weight regulation.  Taubes writes that “…fattening and obesity are caused by an imbalance—a dysequilibirium—in the hormonal regulation of adipose [fat] tissue and fat metabolism.”  Think of the transformation of a skinny 10-year-old girl into a voluptuous young woman.  It’s not over-eating that leads to curvaceous fat deposits, growth of mammary tissue, and increase in height; it’s hormonal changes beyond her control. 

The primary hormonal regulator of fat storage is insulin, per Taubes.  Elevated insulin levels lead to storage of food energy as fat.  Carbohydrates stimulate insulin secretion and make us fat. 

Although it’s a brilliant book, by no means do I agree with all Taubes’ conclusions.  For instance, if carbohydrates cause heart disease, why is glycemic index only very weakly associated with coronary heart disease in men?  It’s way too early to blame cancer and Alzheimers on carbohydrates.  Primitive cultures may not exhibit many of the diseases of civilization because their members die too young.  Taubes is clearly an advocate of low-carb eating.  Why didn’t he directly address the evidence that fruits, vegetables, and whole grains in the right amounts are healthy?

I have to give Taubes credit for thinking “outside the box.”  His search for answers included reviews of esoteric literature and interviews with scientists in the fields of genetics, athropology, public policy, physiologic psychology, and paleontology, to name a few.

Towards the end of the book, Taubes describes a Mediterranean-style or “prudent” diet that is popular these days.  After five years of research for his book, he says that whether a very low-carb meat diet is healthier than a prudent diet “… is still anybody’s guess.”  It’s hard for me to put aside numerous observational studies associating health benefits with legumes, fruits, vegetables, and wholegrains.  So my “guess” is that the Mediterranean-style diet is healthier.  Perhaps the answer is different for each individual.  Heck, maybe the answer is low-carb Mediterranean.  Both Taubes and I are prepared to accept either result when we have proof-positive data.    

Taubes doesn’t base his opinions on late-breaking scientific results.  Instead, his research findings mostly span from 1930 to 1980, especially 1940-1960.  Once the fat-cholesterol (diet-heart) hypothesis took root around 1960 and blossomed in the 1970s, these data were ignored by the entrenched academics and policy-makers of the day. 

To be fair, I’ve got to mention this is not light reading.  A majority of people never read another book after they graduate high school.  Of those who do, many (like me) will have to look up the definition of “tautology,” “solecism,” etc. 

I was taught in medical school years ago that “a calorie is a calorie is a calorie.”  Meaning: if you want to lose excess weight, it doesn’t matter if you cut calories from fat, protein, or carbohydrates.  I really wonder about that now.

Steve Parker, M.D 

Additional Reading

Bray, George A.  Viewpoint: Good Calories, Bad Calories by Gary Taubes.  Obesity Reviews, 9 (2008): 251-263.

Taubes, Gary.  Letter to Editor: Response to Dr. George Bray’s review of Good Calories, Bad Calories.  Obesity Reviews, 10 (2008): 96-98.