Wednesday, September 30, 2009

When Being a Caveman Is a Good Thing

The paleo diet in some version or another has been around for a long time - well, tens of thousands of years actually. More recently, some experts have been advocating for a diet similar to our cave-dwelling ancestors, based on the premise that our metabolism has not changed much in the intervening millenniums.

This article from Nutrition Data looks at the rising popularity of the paleo approach.

Is Paleo the new Mediterranean?

The Mediterranean Diet has been king of the hill for the last several years. While low-carb and low-fat camps continue to trade jabs, each amassing roughly the same number of studies in its favor, the Mediterranean diet (which is neither) has risen above the fray, trumping every diet it's compared with in study after study.

Just last week, for example, I noted a study finding that the Mediterranean diet helped diabetics lose more weight and use fewer medications than a low-fat diet.

But I sense a shift of power (or at least of focus) in the works. The "Paleo Diet" has been garnering a larger and larger share of popular attention and support as the latest Solution To All Our Problems. And now the research community is beginning to test the theory, designing studies that pit the Paleo diet against other dietary prescriptions.

The caveman versus the shepherd


While the Mediterranean Diet hearkens back a couple of thousand years ago to a pre-industrial, agrarian era, the Paleo diet turns the clock back by ten thousand years and attempts to replicate a pre-agricultural, hunter/gather diet. Grains, dairy, legumes, and oils--mainstays of the Mediterranean Diet--are off the table in the Paleo diet, which is based on lean meat, fish, fruits, vegetables, eggs, and nuts.

The two went head to head in a small study of patients with heart disease. Paleo pinned Mediterranean to the mat, yielding greater improvement in glucose tolerance and greater decrease in waist size. Have the cavemen knocked the shepherds off the hill? Not yet.

Studies are one thing; real life is another

For one thing, I wonder about the long-term practicality of the Paleo diet. Diets which depart dramatically from the cultural norm often lead to dramatic weight loss. This may be partly due to the metabolic "magic" put forth by proponents. But I think it's also at least in part behavioral and practical: when whole categories of food are off limits, you tend to eat less and weight loss ensues.

Paleo and other dietary theorists have compelling stories to tell, but what are the realities on the ground? What are the subjects in the study going to eat when the study is over? History has shown that, while purists and zealots may succeed in renouncing grains, carbs, dairy, etc. for life, mere mortals eventually find these diets too difficult to maintain and lapse back into prior eating habits.

And while cutting fat and calories and getting more exercise may seem hopelessly old-fashioned in an era of "good calories, bad calories," let's not ignore the fact that millions of people continue to lose weight and keep it off doing nothing more exotic than that.

Do what works

A change in diet only really improves health outcomes if it's sustainable. And sustainability involves practicality, logistics, economics, personal preferences and beliefs, as well as social conditioning and cultural norms. By all means, let's use what we're learning in the research lab to to nudge our social and cultural norms and public health and food policies in the right direction.

But changing cultural norms takes time. Right now, I think the Mediterranean diet may have a practical advantage over the more extreme Paleo approach. Fortunately, we don't all need to agree on the same solution. If what you're doing isn't producing results, try a different approach. If you've found what works for you, keep doing it. But don't assume that what works for you is the (only) solution for everyone.

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