Original food: the newest view of healthy eating is taking us back to the Stone Age. Here's how to make it work in the modern world - overview of various natural food diets

Despite the fact that we can sit on a beach in Hawaii and talk via satellite phone with someone perched on a glacier in Greenland, humans haven't changed much, genetically speaking, in thousands of years--in fact, just 0.02 percent. But our eating habits have. Our Stone Age ancestors dined mainly on lean animal meat, wild fruits and vegetables, and ate very little sugar or starchy carbohydrates, no added salt and no dairy. This wholefoods, high-fiber diet kept them remarkably free of chronic disease, just as it continues to sustain today's remaining hunter-gatherer societies from the polar regions of Canada to the rainforests of Brazil. By contrast, our modern diet is increasingly based on processed foods, and its calorie-rich, nutrient-poor character has played a starring role in our current high rates of obesity, heart disease, diabetes and cancer.

There's abundant evidence of our abandonment of whole foods in favor of processed ones. Last year, only a third of "home-cooked" dinners were made from scratch, leading Food Technology magazine to name ready-to-eat packaged foods one of the top 10 trends of the year. On any given day, four out of 10 adults dine away from home, according to the National Restaurant Association. Instead of the five to nine servings of fruits and vegetables recommended by federal dietary guidelines, we average only 4.1 servings at home and a woeful 2.9 servings when we dine at fast-food restaurants. And while we do consume six servings of grains every day, only one of them is healthy whole grain.

Yet despite our heat-and-eat, drive-through diets, our bodies remain genetically programmed to thrive on the whole, unprocessed menu of our ancestors. To reverse our risk of illness, we need to eat less like George Jetson and more like Fred Flintstone. But how?

looking back to move forward

Getting more in sync with your DNA doesn't mean you have to start searching the headlands for berries and trapping wild boar. Instead, the challenge is to learn how to fill modern-day nutritional gaps with whole foods. Scientists are now debating just how closely we should be following the lead of those early hunter-gatherers. According to Loren Cordain, Ph.D., professor of health and exercise science at Colorado State University and author of The Paleo Diet, we should adhere to the Stone Age blueprint by completely omitting grains and dairy from our diets. But others take a broader view.

"It's very difficult to draw a parallel between our ancestors' diet and today's because the foods are very different," says Frank Hu, M.D., associate professor of nutrition and epidemiology at the Harvard School of Public Health. Nevertheless, Hu believes those early dietary patterns, such as eating more protein and fewer carbohydrates, are worth mimicking.

carbohydrates then and now

Americans get about 51 percent of their calories from carbohydrates, but not much of that comes from healthy sources such as fruits, vegetables and whole grains. Instead, we're loading up on refined carbohydrates made with heaps of white flour and sugar. These foods contain considerably fewer vitamins, minerals, essential fatty acids, fiber and phytochemicals than complex carbohydrates do.

With the exception of pasta, most refined carbohydrates also score high on the glycemic index scale, meaning they are quickly converted to blood sugar by the body, causing an insulin surge. Subjecting the body to continual insulin peaks may lead to serious health problems, such as obesity, diabetes and even cancer of the prostate, breast or colon.

Our predecessors ate 22 percent to 40 percent fewer carbohydrates than we do--and the calories they ate were unrefined. "Our ancestral diet contained large amounts of plant foods--fruit, vegetables, nuts, roots--that were low on the glycemic index scale" says Cyril Kendall, Ph.D., a nutritional research scientist at the University of Toronto. "We have now switched to an energy-dense diet high in rapidly absorbed starches and sugars. This makes it very easy to overeat and, with a lack of physical activity, may lead to obesity and other problems."

reverse the trend

Eat more fruits and vegetables, and don't stop at five servings a day, the minimum number recommended by health organizations. "The research seems to show that more is better," says Elizabeth Somer, R.D., author of The Origin Diet. "It may be that eight to 10 servings a day is optimal." Indeed, a study of the well-known DASH (Dietary Approaches to Stop Hypertension) diet found that nine servings were most beneficial in lowering blood pressure.

This is one area where access gives us a leg up on Stone Agers, says Cordain. "At times they couldn't get sufficient fruits and vegetables. Technology has enabled us to have such foods all year round." It's also enabled us to have a wider variety of fruits and vegetables, which provide antioxidants, phytochemicals ant/other disease-preventive nutrients.

load up on color

In Eat, Drink and Be Healthy, Walter Willett, M.D., professor of nutrition at the Harvard University School of Public Health, advises getting at least five servings of fruits and vegetables per day, including foods from these categories: