To conduct the study, researchers placed 294 sedentary participants — who had an average age of 51 and most of whom were men — with moderate obesity into three dietary groups at random.
One group was guided on how to increase their physical activity and given basic guidelines on how to have a healthy diet.
The same guidance on physical activity was given to the second group as well as advice on how to follow the traditional Mediterranean diet with calorie restrictions. The diet replaced red meat with fish and poultry and involved consuming 28 grams of walnuts per day. It was also high in vegetables and low in simple carbohydrates.
Guidance on physical activity and how to follow the green Mediterranean diet with calorie restrictions were the focus for the third group. In addition to the same consumption of walnuts and avoidance of red meat as the first group, this group was advised to avoid processed meat and consumed greater quantities of plant matter. The plant-based items consumed were 100 grams of frozen cubes of the flowering plant Wolffia globosa in three to four cups of green tea each day. This high-protein plant was taken as a partial substitute for animal protein in a plant-based protein shake.
At the six month mark, researchers assessed how the traditional and green Mediterranean diet affected weight loss, cardiovascular and metabolic risk factors.
Mediterranean diet participants lost more weight than those on the healthy diet. The green Mediterranean diet resulted in 13.7 pounds dropped and the traditional one led to 11.9 pounds lost. The healthy diet led to a 3.3-pound weight loss.
The green Mediterranean diet also resulted in a greater decrease in waist circumference, with 3.4 inches compared to 2.7 inches from the traditional diet and 1.7 inches from the healthy diet.
Aside from the decrease in “bad” cholesterol Shai stated to Today.com, other improvements associated with the green Mediterranean diet included a decrease in diastolic blood pressure, insulin resistance and an increase in the ratio of “good” to “bad” cholesterol.
“Our findings suggest that additional restriction of meat intake with a parallel increase in plant-based, protein-rich foods, may further benefit the cardiometabolic state and reduce cardiovascular risk, beyond the known beneficial effects of the traditional Mediterranean diet,” researchers wrote.