Why? Because the human body was designed to be put to daily use. Unlike automobile parts that wear out the more you use them, body parts get better the more you use them. By flexing muscles, massaging lymph nodes through movement, moving the walls of blood vessels, providing stresses to bones, and increasing the heart rate through exercise, a person unleashes a windfall of healthy biochemical and physical effects that are fundamental to achieving a state of optimum health. Without exercise, achieving lasting health is simply not possible.
And this is where many Atkins dieters make a wrong turn. Instead of making physical exercise part of their overall health strategy, they may tend to rely on food choices alone, thinking that if they just avoid dietary carbohydrates, they don't need to exercise! It's a distortion, of course, since physical exercise is essential for low-carb diet success. I explain why in great detail in the exercise and strength training section of Low-Carb Diet Warning. The Atkins pyramid clearly support the idea that carbs and grains can only be consumed by a person who engages in frequent exercise.
In this way, the Atkins pyramid is right on target: frequent exercise allows you the "luxury," if you will, of consuming additional carbohydrates. Yet the underlying physiological realities that support this notion go far beyond what most people realize. The general consensus is that more physical exercise allows you to eat more carbs simply because you've burned off that many calories during your exercise. But that's not the real reason at all.
Without exercise, the human body isn't biochemically configured to process carbohydrates. Clinical research shows that a sedentary body will have an exaggerated insulin response to even mild carbohydrates (such as a bowl of oatmeal), where a body subjected to regular exercise will easily and unnoticeably metabolize those carbohydrates without elevating insulin levels. In other words, frequent exercise "reprograms" your body's instructions on how to deal with dietary carbohydrates. A person who engages in regular exercise is truly able to consume more carbs than a person who avoids exercise, without showing any adverse insulin effects. The degree to which an individual response to exercise, of course, varies considerably, which is why the Atkins pyramid states, in the footnotes, "Everyone's metabolism and lifestyle are different. Discover your individual carb level to achieve and maintain a healthy weight."
Despite all this, the fact remains that most low-carb dieters continue to avoid physical exercise. I see this as a real problem based on all the email feedback I've received from readers. The strange thing is that most low-carb dieters realize they should exercise more, but they avoid it anyway. They intellectually agree with the "exercise more" philosophy, but can't seem to whip their hips into action and get the exercise done.
I've especially noticed a pattern of avoidance of strength training with women. Women need strength training more than men, by the way, and older women need it more yet. In fact, the Atkins diet typically results in a greatly increased need to engage in strength training in order to protect the bones against the highly acidic nature of heavy protein consumption. Without exercise, part of a low-carb dieter's weight loss may actually result from bone mass loss! This leads, of course, to osteoporosis. For a more detailed explanation, read the strength training and bone density section of Low-Carb Diet Warning.
Another place where people distort the true intention of the Atkins pyramid is by thinking that ten minutes of walking allows them to eat a jelly donut. This is a fairly typical distortion, actually, where the proportion of exercise to carbohydrates is wildly distorted in the minds of low-carb dieters who absolutely hate exercise and love jelly donuts! In reality, no amount of exercise justifies a jelly donut, and it would take a full hour of fast-paced walking to justify even a single slice of regular bread. It takes a lot more exercise to justify eating carbs than most people realize. So it's easy for people to incorrectly interpret this exercise component of the Atkins pyramid and end up engaging in bizarre dietary practices just because they walked up a few flights of stairs, for example.
Still, hats off to the Atkins team for adding this element. When properly understood and followed by Atkins dieters, it is nothing short of genius. As a low-carb dieter, just remember that the volume and frequency of exercise required to justify additional fruits, nuts and breads is probably much larger than you think. In my own experience, I wasn't able to eat breads without producing insulin spikes until I was engaging in a solid five hours a week of what most people would consider to be aggressive exercise: biking at 15 - 20 miles per hour, climbing the Stairmaster, and jogging. Even now, I don't dare touch bread unless it's that oh-so-chewy low-carb bread.
This article is reprinted from Analysis: The Atkins Lifestyle Food Guide Pyramid, a public education ebook provided free of charge by the non-profit Consumer Wellness Research Center.