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The Flintstone Diet

Stone Age diets are the rage again. The notion that we should return to early-human eating habits resurfaces about once in a generation. In the 1980s the book was The Paleolithic Prescription. Now there’s The Paleo Diet and Neanderthin, among other books. These books rely on a form of evolutionary/genetic determinism, claiming that humans were "designed" to eat lots of meat and that we’re overweight and suffer from heart disease and diabetes because we’ve strayed from this ideal diet. The fact is, we can’t go back, particularly since scientists aren’t even sure what our early ancestors ate. In any case, today’s neo-Paleolithic programs offer highly questionable dietary advice.

Digging up the past

Paleolithic proponents assume that early humans were hunter-gatherers who depended almost exclusively on meat and raw fruits and vegetables, seldom ate cereal grains, and had no dairy products. They speculate that early humans consumed much more animal protein than we do, no refined sugars, more fiber, and much less sodium.

However, evidence about early diets is very fragmentary, coming from tooth marks on animal bones and scattered fossilized remains, as well as extrapolations from today’s hunter-gatherer societies. Any theory of an "average Paleolithic diet" is highly problematic: this period lasted many millennia, and early humans lived in ecological niches with widely varying food sources. They probably ate meat only when they were lucky enough to catch it, and consumed whatever they could find, depending on the season (including insects and leaves, and possibly other people). If they lived near water, they probably ate lots of fish instead of meat. In other words, no one really knows what early humans ate. They certainly were very active. Getting enough food to live on, by itself, took plenty of exercise. Obesity must have been very rare.

How the diets stack up

The Paleolithic diets now being promoted do vary. The Paleo Diet recommends a high-protein, low-carbohydrate diet almost like The Zone. It emphasizes lean meats, since the wild animals early humans fed on were much leaner than today’s domesticated animals, and plenty of fresh fruits and vegetables. It tells you to avoid dairy foods, cereals, beans, starchy vegetables, and salt, along with fatty meats, soft drinks, fruit juices, and sweets. In contrast, the Neanderthin diet is rich in fat and protein, recommending fatty meats, but no grains, potatoes, or milk—it’s an Atkins-style diet in prehistoric garb.

These diet plans do have some good aspects. They rule out junk foods and added sugars, and cut way down on salt. They emphasize nutrient-rich, high-fiber fruits, vegetables, and nuts. Though they claim not to restrict calories, the diets tend to be low in calories (because, like most fad diets, they limit your food choices and rule out entire categories of foods).

There are potential problems, however:

• High-protein and/or high-fat diets pose health risks (see our article on the Atkins diet in November 2002). We recommend cutting down on animal fats, not increasing them.

• Avoiding all grains, especially whole grains, as well as beans, is unwise. If you are overweight and eat lots of refined-grain products, you should cut down on them, but you don’t have to avoid them completely.

• Avoiding all milk and dairy products is a bad idea. Low-fat and nonfat dairy products are healthful and nutritious. The books claim that you can get all the calcium you need from vegetables, nuts, and fish (eaten with bones). That is indeed possible, but most Americans simply will not get enough calcium from nondairy sources (unless they also take a supplement).

No need for a time machine

Very few of our Paleolithic forebears, whatever they ate, suffered from "diseases of civilization" such as heart disease and cancer. They didn’t live long enough to develop them. They didn’t smoke cigarettes. They were not surrounded by an overabundance of high-calorie foods, as we are. But many, undoubtedly, suffered from nutrient-deficiency diseases and starvation.

Imitate our ancestors and eat as many fruits and vegetables as you can. Cut down on highly processed and sugary foods, but don’t increase animal fat. Yes, you’re better off eating four ounces of lean meat rather than a four-ounce cheese danish, but foraging for a carrot or berries would be best of all. Don’t smoke. Exercise as though your dinner depended on it. It’s great to get back to basics, but you don’t need some hypothetical Stone Age ancestors to justify this commonsense advice.

UC Berkeley Wellness Letter, December 2002