The Mediterranean Diet offers a healthy, tasty, aromatic array of fruits, vegetables, whole grains, nuts, wild greens, fish, olive oil, and red wine while sharply reducing intake of milk products, meat, processed foods, sweets, and caffeine. The MD helps prevent cardiovascular disorders, reduce the incidence of cancer and diabetes, and–it appears–curb neurodegenerative processes.

It is strange, therefore, that, in spite of the pressing need to confront the global obesity epidemic, the MD has received relatively little attention in regard to its potential for weight loss. One reason: the centrality of olive oil in the MD seems flagrantly at odds with the need to reduce body fat. Another reason: the MD threatens the profits of the dairy and meat industries, the processed food industry, the beverage industry (except for red wine growers), pharmaceutical companies, and commercial dieting companies. So it is often ignored in discussions of approaches to weight loss. A third reason: the MD is not really a diet at all in the sense of a way of reducing energy intake in order to reduce weight. It is rather a traditional cuisine–a mode of ordinary healthy eating. And it contains no agreed-upon prescriptions regarding portion size or the exact balance of various ingredients.

Nonetheless, the MD can perform splendidly at the very task that is the downfall of other diets: it possesses proven effectiveness as a way of maintaining weight. In almost every clinical trial of medical and commercial diets, the loss of some 2-14 kg over the first 6-12 months gradually gives way to regaining weight, so that after five years the dieter is often no better off than at the outset. In contrast, the palatability of the MD, its satiety-inducing ingredients, its natural appeal, its extensive network of suppliers and recipes, and its freedom from the calorie counting, weight worrying, extra expenses, and counseling typical of other diets make it much easier to pursue over the long term.

Scientific Evidence

We have solid evidence for the effectiveness of the MD in weight maintenance. For instance, high adherence to a MD was associated with lower risk of obesity over 3.3 years in a study of 17,238 women and 10,589 men from the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) (Giugliano D and Esposito K Curr Opin Lipidol 2008). In a recent three-pronged Israeli study (Shai I et al. NEJM 2008), a loosely defined Mediterranean Diet maintained weight loss of about 4.4 kg from Months 5 through 24 of a trial, whereas a low-fat diet group regained about 25% of weight lost in the first 5 months. The Atkins Diet (low carbohydrates) group actually outperformed the MD group, losing 4.7 kg. But it had initially lost more, then regained the lost weight. A 2001 study (McManus K et al., Int J Obes Relat Metab Disord) and other clinical trials found the same pattern of weight maintenance with the MD.

Most people naturally prefer the MD because it provides normal nutrition instead of reducing caloric intake (though that is also an option). In contrast, low-fat diets tend to fare relatively poorly in terms of palatability and the induction of satiety, so dieters often deviate from their prescriptions or abandon them entirely over time. Clearly, the moderate level of fat provided by olive oil in the MD appeals to many eaters. Olive oil’s gastronomic qualities enhance the taste of other components of the MD as well. In addition, there is intriguing evidence that moderate red wine consumption prevents body weight gain, at least in rats (Vadillo Bargallo et al. J Nutr Biochem 2006). Of course, olive oil and red wine in the MD also convey other health benefits not available in diets that radically reduce fat and eliminate alcohol.

One conclusion could be that dieters who lose weight from any other diet should, as their weight loss slows down, switch over to the MD to maintain the weight reduction.

Evidence regarding weight loss with the MD is more fragmentary. It is hard to define a single standard MD; every study uses a different version. Also, the MD blends into the even less well-defined category of a moderate-fat diet. A recent Iranian study (Azadbakht L et al. Br J Nutr 2007), for instance, found that over 7 months a moderate-fat diet (like the MD) and a low-fat one performed equally well, but by 14 months the low-fat group had regained all but 1.1 kg whereas the moderate-fat group kept its loss at 5.0 kg. But the study did not use olive oil, red wine, or other components of the MD. An Italian pilot study (De Lorenzo A et al. Diab Nutr Metab 2001) of a low-calorie, rather well-defined MD in 19 obese women found that they lost 6.6 kg on average over two months. So a low-calorie MD seems to work quite well for losing weight in the short run, and then it can be adjusted to normal MD intake for the long run. Of course, this conclusion requires large, high-quality trials to establish firmly.

A pilot study of a high-protein variant of the MD termed the Spanish Ketogenic Mediterranean Diet, relying heavily on fish and olive oil, reportedly led to an average 14 kg weight loss in obese subjects over 12 weeks (Perez-Guisado J et al. Nutr J 2008). Experimental approaches of this kind require further investigation and may lead to superior outcomes.

The Way Forward

None of the above studies focussed on the contribution of daily activities and exercise to weight loss. But they clearly play a significant role. The rural Cretans of the 1950s who served as the original models of the MD lived lives of considerable physical activity, including a lot of walking. In turn, this suggests a possibly even better solution for losing weight than a low-calorie MD, which might encounter problems of adherence (though there was not a single dropout in the Italian pilot study). Instead of trying to “diet” with the MD, one could just eat three square meals per day of the MD (to maintain weight) and undertake a moderate exercise program that would slowly reduce weight until finally, perhaps after several years, one would reach one’s ideal weight. So it would become a question of getting into shape rather than of dieting.

This approach would not appeal to those who seek quick results, but it would presumably make sense to many medical doctors and to millions of overweight and obese people who have sadly failed with other diets.

Of course, we have just scratched the surface of what constitutes a genuine MD. Future articles will define what foods a true traditional Cretan version of the MD contains and, equally important, what foods don’t belong in it. They will also discuss the quirky anomalies and formidable obstacles that stand in the way of achieving the benefits of the MD for a large number of people in the obesigenic modern world. A sobering reality: even Cretans these days are fast joining the obesity epidemic.

Kenneth J. Dillon

www.scientiapress.com

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