An interesting diet study was published earlier this year, this one from Italy, comparing a Mediterranean diet with a lacto-ovo-vegetarian diet. The Mediterranean diet focused on fruits, vegetables, beans, and whole grains as well as poultry, fish, dairy, and some red meat. The lacto-ovo-vegetarian diet included dairy and eggs but no meat or fish. Both diets are widely promoted as being healthful, and previous research has shown that each can improve aspects of cardiovascular health and help with weight control, but no clinical trial has compared them until now.
Published in Circulation, the study involved 107 relatively healthy but overweight or obese omnivores, ages 18 to 75, who were randomly assigned either a low-calorie lacto-ovo-vegetarian diet or a low-calorie Mediterranean diet for three months. Then the participants switched diets for another three months. They received individual dietary counseling as well as weekly menu plans and detailed instructions about food selection, but no weight-loss goals. The two diets ended up supplying about the same number of calories and had similar levels of carbs, fat, and protein.
Both diets led to a loss of about four pounds. And both reduced cardiovascular risk, but in different ways: The vegetarian diet led to a slightly greater reduction in LDL (“bad”) cholesterol, while the Mediterranean diet led to a modestly larger reduction in triglycerides. Triglycerides rose slightly on the vegetarian diet.
It’s not surprising that overall the diets had “equally effective results,” since they were alike in many ways, except in terms of meat. Both focused on “high-quality,” wholesome foods. And both emphasized nutrient-dense foods such as vegetables, fruits, legumes, whole grains, and nuts. Both diets also limited saturated fats. This being Italy, the vegetarian diet had a Mediterranean slant (thus, both groups averaged about 10 tablespoons of olive oil a week).
Bottom line: There is no “best diet.” This study showed that both Mediterranean and vegetarian dietary patterns can be good for your heart as well as your waistline. Healthful versions of other traditional diets from around the world may well be just as beneficial.