Low-Carb Mediterranean Diet Beats Low-Fat Diet for Newly Diagnosed Type 2 Diabetes

Olive oil and vinegar: prominent features of the Mediterranean diet

I first wrote about this study way back in 2009. To recap how the study was done:

Newly diagnosed type 2 diabetics who had never been treated with diabetes drugs were recruited into the study, which was done in Naples, Italy.  At the outset, the 215 study participants were 30 to 75 years of age, had body mass index over 25 (average 29.5), had average hemoglobin A1c levels of 7.73, and average glucose levels of 170 mg/dl.

Participants were randomly assigned to one of two diets:

1. Low-carb Mediterranean diet:  rich in vegetables and whole grains, low in red meat (replaced with poultry and fish), no more than 50% of calories from complex carbohydrates, no less than 30% of calories from fat (main source of added fat was 30 to 50 g of olive oil daily).  [No mention of fruits or wine.  BTW, the traditional Mediterranean diet derives 50-60% of energy from carbohydrates.]
2. Low-fat diet based on American Heart Association guidelines:  rich in whole grains, restricted additional fats/sweets/high-fat snacks, no more than 30% of calories from fat, no more than 10% of calories from saturated fats.

Both diet groups were instructed to limit daily energy intake to 1500 (women) or 1800 (men) calories.

All participants were advised to increase physical activity, mainly walking for at least 30 minutes a day.

Drug therapy was initiated when hemoglobin A1c levels persisted above 7% despite diet and exercise.

The study lasted four years.

The bottom line for the investigators then was  that “a low-carbohydrate, Mediterranean-style diet seems to be preferable to a low-fat diet for glycemic control in patients with newly diagnosed type 2 diabetes.”

Nevertheless, in 2018 the most commonly recommended diet for diabetics is still a low-fat diet.

What About Long-Term Effects?

In 2014, our indefatigable researchers published additional long-term results of this study’s participants, who were followed for a total of 8 years. That’s an incredibly long time for a diet study. Major findings;

• Compared to a traditional low-fat diet, the low-carb Mediterranean diet postponed the start of diabetes medications by two years , and it wasn’t simply due to weight loss.
• Complete or partial remission of diabetes occurred in 15% of the low-carb Mediterranean dieters within the first year and 5% after six years. These rates were two to four times higher than seen in the low-fat group. (Lower hemoglobin A1c at the start of the study was a predictor of long-term remission. That is, your best chance of remission is when your diabetes is relatively mild when diagnosed.)
• Compared to the low-fat diet group, the low-carb Mediterranean dieters saw a greater reduction in Hemoglobin A1c levels.

I don’t know exactly what these successful low-carb Mediterranean dieters ate, but if you need a low-carb Mediterranean diet now, why not try mine?

Steve Parker, M.D.

Low-Carb Mediterranean Diet, front cover