Posted by: drwbortz | June 21, 2010

Challenging Nutritional Dogmas

One of the sacred cows of nutritional science is that breakfast is the most important meal of the day. All sorts of testimonials preach that, since overnight is the longest interval without calories, it is critical to fuel the furnace upon awakening.

I’m not so sure. As a lifetime student of food and enjoying eating as much as anyone I challenge the seeming certainty that breakfast is critical. One of my skepticisms streams from the fact that I am convinced that my stomach doesn’t wake up till later in the morning. I simply am not hungry when I first wake up.

Almost all of the pro-breakfast statements are anecdotal in type. Virtually none are based on scientific evidence. The claim that student test scores are higher in breakfast eaters or that breakfast is one of a long list of factors associated with longevity just doesn’t satisfy my desire to have well controlled, rigorous research supporting advocacy for breakfast. I am also cynical enough to believe that most of the breakfast preaching derives from the manufacturers of sugared cereals.

None of this is to say that I feel that the timing of the day’s calories doesn’t matter. In 1969 as a part of a large NIH-funded grant “The Effect of Diet on the Metabolism of Fat in Man,” I published a research paper in the journal Metabolism,” The Effect of Feeding Frequency on Diurnal Plasma Free Fatty Acids and Glucose Levels.”  Under strictly-controlled laboratory conditions I fed volunteers their liquid synthetic iso-caloric meals as one, three, and nine feedings. The “gorgers,” with only one big one meal, had markedly different blood fat and glucose levels than the “nibblers,” who had nine equal feedings. So timing does have an effect, but I still am not convinced of breakfast’s primacy.

Another of my nutritional skepticisms involves carbo-loading before an athletic event. Since we all originally came out of Africa we should look at our Paleolithic ancestors to see if they sat down for a hearty breakfast before they went out for a 20-mile hunting jaunt.  It seems more likely that hunger, maybe even bordering on starvation, was their more likely nutritional situation.

Our bodies are extremely smart in choosing the calories they need and stored fat is a magnificent fuel , as it fulfills this need for energy, when it is not present in excess.  Our ancestors preferred fatty meat because of its caloric density. Irven De Vore wrote, ”They eat as much as much meat as they can catch, and as much carbohydrate as they need.”  It would be unwise for our metabolism to flaunt this preference.

Besides, I have now run 40 marathons most of them on an empty stomach, like the bushmen.  Fat is stored amply within muscle fibers and is the predominant endurance fuel.  Even the brain can use fat as ketone bodies for energy.

One of the truisms of my life is to trust the wisdom of the body. When it is not hungry, I don’t see why I should sit down and gorge calories when the stomach says, I’m not hungry.

My usual breakfast of a glass of orange juice and a cup of coffee surely excommunicates me from the food establishment , but having written dozens of scientific papers and having run 40 consecutive annual marathons gives me confidence that my insights may be right after all.

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