You may already be familiar with one of the world’s most popular healthy diets. That would be the Mediterranean diet — an eating plan rich in whole grains, fruits, vegetables, legumes, fish, and healthy fats like nuts and olive oil, and which even allows some dark chocolate and red wine. This eating style limits red meat, processed foods, and added sugars, and registered dietitians tend to praise the plan for its heart and weight benefits. In 2021, for example, U.S. News & World Report ranked the Mediterranean diet as No. 1 in Best Plant-Based Diets, Best-Heart Healthy Diets, Best Diabetes Diets, Best Diets for Healthy Eating, Easiest Diets to Follow, and — last but not least — Best Diets Overall for 2021.

But could the Mediterranean diet get even better? Maybe, suggests a study published in November 2020 in Heart.

In the randomized controlled trial, researchers found that following a “green” Mediterranean diet for six months resulted in a greater decrease in measures of “bad” LDL cholesterol, diastolic blood pressure (the second number on a blood pressure reading), and inflammatory markers compared with following a traditional Mediterranean diet or adhering to general healthy diet advice (the control group). Weight loss between the two Mediterranean diet groups was similar — 14 pounds (lbs) in the green group, 12 lbs in the traditional (on average) — though the green Mediterranean diet group saw a higher reduction in waist circumference in men.

But what is the green Mediterranean diet, and how does it differ from the standard Mediterranean diet?

The Green Mediterranean Diet vs. the Standard Mediterranean Diet

The standard Mediterranean diet aims to follow the traditional eating patterns of Mediterranean cultures. It emphasizes choosing whole grains, fruits, vegetables, beans, herbs, spices, nuts, and olive oil, according to Oldways.

That’s supplemented with fish or seafood about twice a week, along with moderate amounts of dairy, eggs, and poultry. The diet discourages eating red meat and sweets, and you’ll also want to steer clear of processed foods, which are often packed with added sugars and sodium. This eating plan also allows you to drink up to one glass of red wine per day (though if you don’t already drink, you’re not encouraged to start).

The green Mediterranean diet avoids red and processed meat entirely, while placing plants in the spotlight in a way that goes above and beyond that of the standard Mediterranean diet. You’ll still opt for traditionally “good” Mediterranean-style foods, like whole grains and fresh produce. In addition, there are three daily components to the diet, as followed by participants in the Heart study:

100 grams (g) of a Mankai duckweed shake (Not familiar with duckweed? It’s a type of protein-rich aquatic plant, per a December 2019 article in Clinical Nutrition.)
Three to four cups of green tea
One ounce of walnuts (Disclosure: The research was partially funded by the California Walnuts Commission.)

Why make these changes? “The Mediterranean diet has proven benefits, but we thought it might be improved upon by adding more foods rich in polyphenols and further reducing red meat,” says Meir Stampfer, MD, DrPH, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health in Boston and an author on the Heart research.

How Does the Green Mediterranean Diet Work Exactly?

The green Mediterranean Diet is low in calories and carbohydrates, and high in protein. A sample day, according to the authors of the Heart study, might aim for 1,500 calories per day for men and 1,200 to 1,400 calories per day for women, which includes 40 g of carbs and 100 g of protein. (After two months, carbohydrate intake increases to 80 g per day.) Exercise, reaching up to five days a week, is also encouraged.

Based on prior clinical trials, researchers identified an X-factor in what made other diets especially healthy: antioxidant-rich plant compounds called polyphenols, says Heart study author Iris Shai, PhD, adjunct professor of nutrition at Harvard T.H. Chan School of Public Health in Boston. For that reason, in the green Mediterranean diet, there’s an emphasis on several high-polyphenol foods, including Mankai (duckweed), green tea, olive oil, almonds, red onion, and broccoli. Duckweed is particularly rich in protein, iron, and vitamin B12, which makes it a good meat substitute, she says.

What Are the Potential Benefits of a Green Mediterranean Diet?

As the Heart study showed, following the green Mediterranean diet improved “bad” LDL cholesterol levels, diastolic blood pressure, and inflammatory markers more than the traditional Mediterranean diet. Researchers calculated the Framingham risk scores (a measure of expected cardiovascular disease risk after 10 years) of the three eating patterns studied, and found that individuals on the green Mediterranean diet saw the greatest risk reduction. Their scores fell by 3.7 percent, while the traditional Mediterranean diet had 2.3 percent lower scores, and the control group had 1.4 percent lower scores.

But the possible benefits don’t end there. “We also found a dramatic reduction in the level of fat in the liver, which is closely linked with diabetes risk and related metabolic outcomes. Importantly, these benefits were demonstrated in comparison to an already very healthy diet,” Dr. Stampfer says, coauthor of an article on the study published in January 2021 in Gut.

“The Mediterranean diet has always been held up as one of the healthiest plans we know of,” says Sharon Palmer, RDN, a plant-based dietitian based in Duarte, California, and an advisor for Oldways. She adds that it’s possible to follow the Mediterranean diet while incorporating other elements that are known to carry health benefits, like a regular intake of green tea.

While both the traditional and Green Mediterranean diet emphasize plant-based eating, the green diet takes things a step further by swapping in a duckweed shake for animal protein at dinner. And while both diets were beneficial for heart and metabolic health, this trial hints that if you add more plants to your plan, it’s probably better for you, Palmer suggests. Still, the traditional Mediterranean diet has a very long history of positive health outcomes — it is, after all, the traditional diet of countries along the Mediterranean, whose populations are noted for their longevity, notes the Mediterranean Diet Roundtable.

Still, it’s important to keep your expectations in check. After all, scientists don’t yet know the potential long-term benefits of a green Mediterranean diet because it is so new.

Can Following a Green Mediterranean Diet Help With Weight Loss?

Because it’s a low-calorie diet that encourages minimizing processed foods and emphasizing whole foods, it’s no surprise that the green Mediterranean diet can help people lose weight. In the Heart study, after six months, participants following the green Mediterranean diet lost an average of 14 lbs, while those on the traditional Mediterranean diet lost 12 lbs. (Both diets restricted people to the same number of calories.) The authors note that while the amount of weight lost was similar between the groups, it was about 4 times higher than the control group, which lost only about 3 lbs over the course of the study.

Notably, the men on the green Mediterranean diet lost more belly fat than males following the traditional diet. Reducing excess belly fat can help lower your risk for type 2 diabetes, heart disease, and stroke, according to the Centers for Disease Control and Prevention (CDC).

One important thing to remember: As the authors point out in the study, participants followed the diet for six months, a time period in which most dieters lose weight quickly. After that initial loss, dieters (on any diet) tend to slowly regain weight. Ideally, more research is needed to know the long-term weight loss potential of this diet.

Prior evidence on the Mediterranean diet may give reasons to be optimistic, though. In an April 2019 study published in Nutrition & Diabetes, which included more than 32,000 people, participants who reported better compliance to an Italian Mediterranean diet were more likely to maintain a stable weight over five years.

They were also at a lower risk of becoming overweight or obese, or developing abdominal obesity, compared with those who didn’t follow this dietary pattern.

A Detailed Green Mediterranean Diet Food List to Follow: What to Eat and Avoid

The green Mediterranean diet, as followed by the Heart study participants, emphasizes the consumption of plant-based protein via a Mankai (duckweed) shake. If Mankai doesn’t appeal to you, or if you can’t find it available locally, don’t worry — there are plenty of other plant-based protein sources you can incorporate into your diet, such as chickpeas, tofu, nuts, beans, and even peanut butter.

Other hallmarks of the diet include a serving of walnuts daily and three to four cups of green tea. And of course, the usual Mediterranean diet staples — whole grains, fresh produce, olive oil — should be included, too.

Eat

Green tea
Water
Mankai (duckweed), or plant-based protein powder
Nonstarchy vegetables, such as broccoli, green beans, cauliflower, and onions
Leafy greens
Tomatoes
Fruit
Eggs
Cottage cheese
Yogurt
Almonds
Walnuts
Olive oil
Tahini
Herbs
Spices
Fish and poultry (in limited amounts)

Avoid

Red meat
Processed meat
Highly processed foods (snack foods like chips, crackers, and cereals)
Desserts
Soda and other sweetened beverages

A 7-Day Sample Green Mediterranean Diet Meal Plan

The following is based off of a sample menu used in the Heart study. It is largely regimented. For guidance on how to incorporate the basics of a Green Mediterranean Diet (more plants, less meat), review the below section on the pros and cons of this diet.

Day 1

Breakfast A cup of cottage cheese, and an omelet with herbs, along with a cup of green tea with cinnamon

Snack A cup of green tea with cinnamon

Lunch A plate of fish with olive oil, a salad with red onion and vinaigrette, and a side of green beans

Snack A small handful of almonds and a cup of green tea