Along the way more than a few skeptics have suggested a problem with emulating traditional hunter-gatherers: Their average life expectancy ranged from 21 to 37, according to a 2007 study by evolutionary anthropologists at UC Santa Barbara and the University of New Mexico. Sisson has no patience for this line of argument. In prehistoric times, he argues, “the world was fraught with danger, starvation, and death in childbirth. We’ve found that if hunter-gatherers survived disease, wars, and tiger maulings, many actually maintained a very robust composition until they were in their seventies and eighties. Their potential life span was probably 90.” By contrast, he goes on, the relatively long lives many of us enjoy today can be attributed largely to medical advancements rather than good nutrition or healthful living. “We’re keeping people alive with medicine—statins, blood thinners, surgery, stents, and valves—who otherwise would have died a long time ago.”
There’s little debate about the benefits of less-processed foods or regular exercise, whatever the form. Where the paleo lifestyle tends to draw the most fire is in regard to fat. Someone on a paleo diet might derive as much as 50 percent of his or her daily calories from fat, while the American Heart Association recommends no more than 25 to 35 percent. “The high saturated fat content of this diet is of concern, since it can adversely impact cardiovascular health,” says Gregg C. Fonarow, M.D., professor of cardiovascular medicine at UCLA and codirector of its Preventative Cardiology Program. Sisson says blame the carbs, not the fat. When you eat fewer carbs, your liver starts turning fatty acids into ketones—compounds the body can burn for fuel. It’s all those carbs, he contends, that trap the fat in our system. “Even the most ardent anti-fat guys will admit there has never been a proven correlation between saturated fat and heart disease,” he says. That’s a controversial statement, but some researchers are coming around: A 2010 analysis of 21 studies in The American Journal of Clinical Nutrition concluded that “there is no significant evidence” that eating saturated fat increases heart disease risk.
Still, not even all paleo proponents agree on this topic. The University of Colorado’s Cordain recommends eating lean cuts of meat and making animal fat a lower percentage of one’s calorie count. But he may be changing his position. “Some people seem to do better on higher-fat versions of the Paleo Diet,” he writes in his recently released book, The Paleo Answer.
The actual amount of meat in paleo meals may be less than critics believe, however. While portions are intended to be unlimited, the meals are more satiating, leading to less overeating, Sisson says. Here’s a typical weight-loss dinner from his book The Primal Blueprint: six ounces of broiled wild salmon, six ounces each of steamed asparagus and zucchini with a pat of butter, five ounces of red wine. It’s hardly outrageous; if you’re looking for meals of giant Fred Flintstone dinosaur ribs, you won’t find them here.
Because the paleo diet is relatively simple—protein, vegetables, hold the bread—it’s easier to follow than many food plans. “Every time I go to a new American or Italian restaurant, it will have pretty good meat entrées you can order instead of pasta,” says Andy Ross, guitarist for the L.A.-based band OK Go, who credits paleo with improving his energy, digestion, and sleep. Better yet, Ross says, is that he can sustain those benefits without being puritanical about it. On their blog, Cheat Day, Ross and his OK Go bandmate, bassist Tim Norwind, celebrate weekly non-paleo meals of huge sandwiches, sugary desserts, and other treats developed within the last thousand years.
Nor is the plan strictly for would-be cavemen. Last year Nell Stephenson, a West L.A.-based nutrition consultant, detailed what she calls a more feminine approach in her book Paleoista. It’s easy enough to get a fresh salad with a bunless turkey burger, and you can find wild boar or venison at some of the more exotic restaurants, she says. Stephenson takes some clients on shopping field trips through Ralphs to help them find everything they need.
With a few tweaks to their diets, even L.A.’s many vegans and vegetarians can become, if not hunters, then respectable paleo gatherers, says Sisson. “When you cut out processed grains, sugars, and vegetable oils, the fact that you’re not getting ideal sources of protein or fat becomes less of an issue. The most important thing you can do is get rid of all the crap.”
Sisson admits there will always be doubters who call paleo extreme or a “fad diet.” But for fans, it’s here to stay. The last 40,000 years? That was the fad.
*The image accompanying this post has been updated.