Question: Jennifer Aniston does it. But should you?|
The Skinny on the Zone Diet
by Liz Neporent|
I have been reading a number of your articles regarding diet and have noticed that you seem to have many good things to say about Dr. Barry Sears' "The Zone" approach. But I have also read articles by another expert who takes a very dim view of the Zone. One area on which you seem to disagree a lot is the infamous food pyramid, which has been burned into our minds. Can you help me understand how two experts could differ so much?
Sure. It's very confusing to the general public when people to whom they turn for expert opinions differ so strongly, yet this kind of range of opinion is pretty much a fact of life in virtually every area of specialization. Facts are only as useful as the interpretations we draw from them. On any given subject there are thousands and thousands and thousands of "facts." Sorting through all the information, deciding what is most important and then making interpretations is a very individual judgment, and it's why many well-meaning people can genuinely differ in the conclusions they draw.
Nutritionists, like all professionals, differ in their training and in their orientations. Like politicians, some are more "conservative" and some are more "liberal." For example, registered dietitians tend to have a very conservative training and tend to follow the lead of orthodox medicine. While there are certainly exceptions, most tend to believe in the food pyramid and support the idea that the conventional high-carbohydrate, low- fat diet is the one and only "best" way to eat in a healthy manner.
This orthodoxy is being questioned and challenged more and more by many leading doctors and nutritionists, though at this time the "challengers" remain in a minority, albeit a vocal and sophisticated one. Obviously, I am in the camp of the challengers and the other expert you refer to is one of the "defenders."
In my opinion, since we as a country adopted a low-fat diet high in refined foods and sugar and high in processed carbohydrates, we have seen epidemics of obesity, heart disease and especially of type II diabetes. We are now finding out that cholesterol levels alone -- which was a big reason that everyone was so afraid of fat -- are not such a reliable predictor of heart disease after all. We now have information about the relationship between insulin and heart disease, hypertension and diabetes that we did not have 25 years ago, and it is safe to say that high levels of insulin are a risk factor for many of these diseases. High-carbohydrate diets raise insulin levels, dangerously so in susceptible people, moderately so in almost everyone else. Coincidental with this, many experts believe that fatty acid deficiency in this country is rampant. They believe that fat per se is not the problem we thought it was, but rather, it's the kind of fat we eat that causes mischief.
For all these reasons, I find it very hard to endorse a high-carbohydrate, low-fat diet and impossible to endorse it as a weight-loss tool. There are other people who feel differently than I do. Though I continue to believe that no one diet works for everyone, and that there is considerable individual variation in our response to different foods and food groups, I think a Zone-type diet is overall a smart place to begin, with the understanding that every person may need to adjust the percentages somewhat depending on their goals and individual metabolism. I think a diet of 40 percent carbohydrates, 30 percent protein and 30 percent fat makes far more sense and is much more balanced than the standard 60 percent carbohydrate, 15 percent protein diet that most conservative dietitians continue to recommend.
As far as the food pyramid goes, there are many things wrong with it. For one thing, I do not believe most people should be eating anywhere near the number of carbohydrate servings it recommends from grains, breads, pastas and rice and cereals, especially from the kind that are most widely available to us in our supermarkets. The pyramid makes no distinction between refined, processed carbohydrates, such as commercial cereals and breads, and true whole-grain products. The food pyramid lumps sugars and fats together, which is a huge mistake. There is absolutely no need in the human diet for refined sugar. On the other hand, there is a definite need for fats, and some fats, such as the ones found in fish, nuts and olive oil, are extremely healthy. Finally, the food pyramid assumes that everyone is biologically and metabolically the same, which is demonstrably wrong. As nutritional anthropology has shown time and time again, some people do very well on high-fat, high-protein diets, some do very well on high-carbohydrate (non-processed) diets, some do much better without dairy, some do okay on predominantly vegetarian diets, and some do much better with meat.
The food pyramid is an invention of the U.S. Department of Agriculture in the late 20th century. Most of the foods on it did not exist before the invention of agriculture. If the history of the human genus were a 24-hour clock, agriculture was invented about 5 3/4 minutes ago. On this same clock, the food pyramid is less than 17 seconds old. To assume it is the last word on the best kind of fuel for the human body is, in my humble opinion, utter folly.