What factor did researchers miss when praising the Mediterranean diet of Crete?
The Short Answer
Fasting. When researchers studied the famously healthy Cretans in the 1950s and 60s, they documented the olive oil, fish, vegetables, and wine — but largely overlooked that these Greek Orthodox Christians fasted for significant portions of the year. The traditional pattern included fasting periods totaling roughly 180 days annually, including complete fasts and partial fasts restricting animal products. The Mediterranean “diet” wasn’t just about what they ate, but also about when and how often they didn’t eat.
Something to Sit With
If the Cretans’ remarkable health came from both what they ate and when they didn’t eat, what does that suggest for your own approach?
Are you focused entirely on food composition while ignoring eating patterns?
Learn More
The Seven Countries Study.
The famous Seven Countries Study, led by Ancel Keys beginning in 1958, documented remarkable cardiovascular health among people in Crete. Researchers catalogued their dietary patterns — high in olive oil, vegetables, legumes, fish, moderate wine — and attributed the health benefits to these foods.
This research launched decades of Mediterranean diet enthusiasm. Olive oil became a health food. Wine got positioned as cardioprotective. The Mediterranean diet became synonymous with healthy eating.
But the research focused on food composition while largely ignoring eating patterns.
What the Researchers Missed.
The Cretan population followed Greek Orthodox religious traditions, which include extensive fasting practices:
Great Lent: 48 days before Easter, with strict fasting (no meat, dairy, eggs, fish, oil, or wine on most days).
Assumption Fast: Two weeks in August before the Assumption of Mary.
Christmas Fast: 40 days before Christmas.
Apostles’ Fast: Variable length before the Feast of Saints Peter and Paul.
Weekly fasting: Wednesdays and Fridays throughout the year.
Add these together, and traditional Greek Orthodox practitioners were fasting or eating restrictively for approximately 180-200 days per year — roughly half the time.[1]
The Confounded Variable.
When you observe a population and note their good health alongside their diet, you attribute the health to the diet. But if that population also fasts regularly, how do you know which factor matters more?
Studies by Sarri and colleagues examining Greek Orthodox Christians found that those who adhered to fasting traditions had better health markers — lower cholesterol, lower BMI, reduced inflammatory markers — compared to those who didn’t fast, even within the same population eating similar foods.[2]
The fasting periods meant:
- Regular insulin reduction
- Periodic caloric restriction
- Extended time without food
- Natural metabolic flexibility
These are precisely the mechanisms we now understand support metabolic health.
The Modern Mediterranean Diet.
When the Mediterranean diet was exported to the rest of the world, the fasting component was stripped out. What remained was:
- Lots of olive oil
- Wine with meals
- Fish and vegetables
- Legumes and whole grains
People adopted the foods without the eating pattern. They added olive oil to their existing meals without removing meals. They added wine without subtracting other calories. They ate Mediterranean-style — constantly, all day, every day.
The modern “Mediterranean diet” is a food list, not a lifestyle pattern. It captures what the Cretans ate while ignoring when they ate and when they didn’t.
The Implication.
This doesn’t mean the Mediterranean food choices are bad — olive oil, vegetables, and fish are excellent foods. But it suggests that focusing exclusively on food composition while ignoring meal timing misses a crucial element.
The healthiest populations throughout history have generally combined:
- Whole, unprocessed foods
- Limited eating windows or regular fasting periods
- Physical activity integrated into daily life
- Strong social and community connections
Extracting just one element — the food list — and expecting the same results may be naive.
Further reading:
- Sarri KO et al., “Effects of Greek Orthodox Christian Church fasting on serum lipids and obesity”[3] — BMC Public Health, 2003
- Trepanowski JF, Bloomer RJ, “The impact of religious fasting on human health”[4] — Nutrition Journal, 2010
- Keys A et al., “The diet and 15-year death rate in the seven countries study”[5] — American Journal of Epidemiology, 1986
- Nestle M, “Mediterranean diets: historical and research overview”[6] — American Journal of Clinical Nutrition, 1995
Written by AI, directed and approved by me. How this is made →