As nutrition research evolves, the idea of the “perfect” diet is changing, too. Over the years, diet advice has been a rollercoaster ride that’s left many of us with intellectual (not to mention culinary) whiplash. For many years, fat was vilified as the bogeyman that’d make you pack on pounds, but more recent evidence shows this macronutrient definitely deserves a place on your plate.
The Mediterranean diet and the keto diet are two popular diets that don’t shy away from fat — and there’s evidence that both can help you reach your goals for weight loss and general health. But with all the information out there, it can be difficult to decide about which one is right for you.
Wondering whether it’s best to embrace the high-fat, low-carb keto concept or dive into a sea of fish and olive oil on a Med diet? To help you decide which makes sense for you, we’re taking a look at the evidence for the effectiveness of these two diets.
The ketogenic diet is a low-carb eating plan first formulated in the 1920s as a therapy for children with epilepsy. More recently, though, the diet has been studied for its efficacy for everything from weight loss to killing cancer cells. The basic premise behind a keto diet for weight loss is to put the body into a metabolic state called ketosis. In this state, rather than using carbs as energy, the body begins to burn fat for fuel. The result? A rapid drop in weight.
The keto diet is very low in carbs (5% of calories or less), high in fat (as much as 80-90%), and moderate in protein (15% or more). But this macronutrient breakdown is merely a guideline; your personal macros may look different. (You can see for yourself with this handy macro calculator.)
Other than its division of macronutrients, there aren’t many hard and fast rules around keto. Unlike other diets that dictate exactly what and when you eat, keto offers quite a lot of freedom. That said, certain foods are inherently more advisable, while others are somewhat off the menu.
Keto-friendly foods include:
- Healthy oils, such as olive, avocado, and walnut oil
- Fatty nuts, nut butters, and seeds
- Full-fat dairy like butter or ghee
- Animal proteins including beef, poultry, organ meats, and fatty fish
- Non-starchy and low-carb vegetables (see our guide to the best vegetables on the keto diet)
Foods to avoid on the keto diet include:
- Fruits, especially those high in sugar
- Starchy vegetables like potatoes, carrots, or beets
- Legumes like beans and lentils
- Most grains, such as bread, pasta, rice, and quinoa
- Pastries, candies, and other sweets
- Processed foods
- Sweet drinks and most alcoholic beverages
The Mediterranean Diet, as its name suggests, is based on the dietary choices of people living around the Mediterranean Sea. It was first identified by researcher Ancel Keys, who traveled this part of the world shortly after World War II, studying the eating habits of people in Italy, Spain, and France.
Though various cultures living around the Mediterranean have distinctive eating patterns, the diet generally contains about 30% fat, 20% protein, and 50% carbohydrates. Its meals focus on foods high in mono- and polyunsaturated fats, fiber, and antioxidants. Fatty fish, beans, whole grains, fruits and vegetables, and even a moderate intake of wine (especially red wine) are all included.
Food isn’t the only important factor in a Mediterranean diet. A true Mediterranean lifestyle includes regular physical activity and making meals a social event. The idea goes that these holistic elements work together to achieve many of the Med diet’s benefits.
Mediterranean diet foods include:
- High-quality oils, mostly olive oil
- Beans and legumes, such as beans, peas, and lentils
- Nuts and seeds
- An abundance of fruits and vegetables
- Moderate amounts of dairy, especially yogurt and cheese
- Seafood as the main source of non-vegetarian protein — at least twice a week
- Unrefined whole grains, including brown rice, quinoa, and whole-grain breads
- Moderate amounts of wine, especially red
Foods to avoid on the Mediterranean diet include:
- Red meat (consider red meat a flavor booster, rather than a main course; try to limit your intake to two servings per week or less)
- Refined grains
- Refined sugars
- Processed foods
- Low overall amount of meat products, besides fish
Despite their different origins and reputations, the keto and Mediterranean diets have some surprising similarities.
First, both can be generous in fat. At around 70-80% of daily calories from fat, keto certainly tops the Mediterranean diet’s smaller allotment — but some research shows that a Mediterranean diet’s macros are somewhat flexible. The average fat intake on a traditional Greek diet, for example, is higher than the usual 30%, sometimes exceeding 40% of daily calories. Like keto and most other low carb diets, this puts Mediterranean fat intake higher than low-fat dietary guidelines.
As for protein, the two diets have plenty of overlap, with typical intakes averaging around 20-25% of calories from this macro.
Regarding the foods you’ll eat regularly on each eating plan, there’s also some overlap. Both ketogenic and Mediterranean diets encourage eating plenty of whole, minimally processed foods, while avoiding those loaded with sugar and refined carbohydrates.
Some specific foods, like fatty fish, nuts, eggs, lean meats, and leafy greens, have a place on either meal plan.
And fortunately, neither diet requires you to purchase specialty ingredients or branded foods. Without much fuss, you can craft your menus for both keto and a Mediterranean diet with common, familiar foods.
The two diets also both work well for those who like their freedom. Since neither is proprietary to any company or its branded foods, it’s up to you to forge your own path with each.
For all their similarities, the keto and Mediterranean diets still aren’t kissing cousins. The two eating plans differ in some significant ways.
Whereas a Mediterranean diet includes lots of carbohydrates (including fruits, whole-grain breads, and pasta), the ketogenic diet is strictly very low in all carbohydrates, even the unrefined versions.
Regarding fat, keto is not only significantly higher in fat than a Med diet, but emphasizes different types of fat as well. A Med diet focuses on unsaturated fats from oils and fish, but keto foods include high amounts of both saturated and unsaturated fats. (Don’t worry! Research shows saturated fats may not be heart health troublemakers, as was once believed.)
With most calories coming from fat, a keto diet is also heavy on animal products, while a Mediterranean diet puts plants at the center of the plate. So as you consider which one is right for you, ask yourself: Do you relish foods like steak, eggs, butter, and avocados — or prefer to get most of your calories from veggies with far less meat?
If you’re contemplating diving into a keto or Mediterranean diet, you’re likely hoping to experience their benefits for your health. Use these head-to-head, evidence-based comparisons to make your decision easier.
Unlike diets that rely primarily on cutting calories, a keto diet is designed to “hack” the body’s metabolic state through ketosis — and, without a doubt, this method gets results. Once the body reaches ketosis, the liver burns through fat for fuel, leading to a slimmer, lighter you, often with less hunger and without calorie-counting. A 2021 review that analyzed dozens of studies revealed that, in all of them, a ketogenic diet was shown to cause dramatic weight loss. (Though it’s worth noting that many of these diets were also very low in calories, which may have affected weight loss, too.)
The Mediterranean diet also offers plenty of potential for weight loss. A 2016 review that looked at five studies with 998 participants found that people who stuck with a Med diet for 12 months or longer succeeded in losing an average of about 9 to 22 pounds — significantly more than people on low-fat diets and similar (in the studies reviewed) to low-carb diets (like the keto diet).
We’ll admit that to many people, the high-fat keto diet might seem counterintuitive as a strategy for cardiovascular health.
Since decades of expert advice (much of it subsequently wrong) steered us away from saturated fat, it’s only natural to question how good this way of eating could be for the heart.
More research is needed to determine exactly how long-term adherence to a keto diet may affect heart health, but there’s reason to believe it’s not a doom-and-gloom scenario.
Experts haven’t necessarily developed a consensus yet, but according to a recent report in the Journal of the American College of Cardiology, ketone bodies produced on a keto diet could help protect the heart in people with cardiovascular disease.
As for the Mediterranean diet, experts have sung its praises for heart health for many years — and that’s not controversial or hotly debated.
A large 2013 study found that following the diet (even without any calorie limit) reduced the relative risk of heart disease by 30%. Similarly, a more recent analysis of 45 studies confirmed that the more diligently people followed a Mediterranean diet, the less likely they were to have heart attacks, strokes, and cardiovascular disease.
An estimated 34 million Americans have diabetes. Diet is a key factor in preventing and managing this life-altering condition, and research suggests both the keto and Mediterranean diets may offer benefits for this metabolic condition.
Research shows that a ketogenic diet can be very effective for blood sugar control in people with diabetes, likely because of its super-limited amounts of carbohydrates. (Long story short: When you’re not eating a lot of carbs, they can’t spike your blood sugar.)
On the other hand, the anti-inflammatory nature of a Mediterranean diet can also help keep diabetes at bay. A JAMA study published in 2020 that tracked over 25,000 women for 20 years linked a Med diet with lower insulin resistance and overall risk of developing type 2 diabetes.
The Keto-Mediterranean Diet: Best of Both Worlds
The keto and Med diets each offer so many proven advantages. Wouldn’t it be great if you could combine the two? You can!
Some people follow a so-called “Ketogenic Mediterranean Diet,” a plan that incorporates the best of each diet. The diet features about 7-10% carbs, 55-65% fat, 22-30% protein, and 5-10% alcohol — however, you don’t necessarily need to follow each of those macronutrients closely. But rather watch your food selection and limit carbohydrate intake.
To achieve this breakdown, this eating plan takes the fats included on a Mediterranean diet (olive oil, fatty fish, cheeses, etc.) and adds even more of them to reach the target fat range of 55 to 65% of total calories. Meanwhile, it allows for greens, non-starchy veggies, and a moderate amount of red wine. Just like with the keto diet, starches, sugars, and most grains are dramatically limited (or eliminated).
Though there’s not as much research on the keto-Mediterranean diet as either of the diets on their own, the existing studies are promising.
For example, one Spanish study found that following a combination keto-Med diet resulted in significant weight loss, reduced blood pressure, lower total cholesterol, and lower blood glucose levels.
Another study from 2013 found that alternating between strict keto for about a month followed by 4-6 months of Mediterranean diet may help decrease weight regain and support other health areas. In other words, if you’re going to go off the keto diet, the Mediterranean diet could be your perfect backup option.
Foods to include on a keto-Mediterranean diet:
- High amounts of healthy oils (especially coconut and olive) and other plant fats like avocados
- Fatty fish as the main protein source, along with other seafood, eggs, cheese, and lean meats (Note: Even though saturated fat doesn’t appear to be the villain it was once made out to be, you can still limit it and remain keto-compliant if you prefer)
- Leafy greens
- Non-starchy vegetables
- A moderate intake of red wine
As different as they may seem, the keto and Mediterranean diets can both help you achieve better results for health compared to most ways of eating. Wth their mutual emphasis on whole, unprocessed foods, either is a huge improvement over the highly processed Standard American Diet.
Ultimately, you can start with whichever one you feel most attracted to and rest easy knowing that you’ve made a healthy choice. Or try both and allow your preferences and results to determine the verdict — and as we covered, even switching back and forth between the keto and Mediterranean diet appears to be an effective, healthy way to eat.
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