Based on the traditional diet patterns of countries including Italy, Spain, and Greece, the Mediterranean diet was first defined by physiologist Ancel Keys in the 1960s (
Meanwhile, though the ketogenic (keto) diet was introduced in 1921 as a treatment for epilepsy, it has only gained traction among the general population within the past few decades (
While both diets are often used by those looking to lose weight, improve heart health, and boost energy levels, many may wonder which is more beneficial.
This article will compare the key benefits and downsides of the Mediterranean diet and keto diet to help determine which is right for you.
The Mediterranean diet and ketogenic diet both limit and restrict different foods.
While no foods are technically excluded on a Mediterranean diet, there are certain foods that should be limited.
For example, red meat — such as beef, pork, and lamb — is only enjoyed occasionally while following the Mediterranean diet. Instead, other protein sources like poultry, seafood, and legumes are consumed more regularly (
Processed foods and sweets are also limited, which includes refined grains, processed meat products, convenience meals, and foods high in added sugar (
Additionally, sugar-sweetened beverages are typically avoided, including soda, sweet tea, and sports drinks.
Compared to the Mediterranean diet, the keto diet is much more restrictive.
The ketogenic diet involves increasing your consumption of fat and strictly limiting carb intake to enter ketosis, a metabolic state in which your body uses fat for fuel instead of sugar (
Though there are no specific guidelines for which foods you must limit or avoid, many foods are unlikely to fit into your daily allotment of carbohydrates, which usually ranges from 20–50 grams per day (
Therefore, a typical keto diet often eliminates many high carb foods, including nutritious ones like fruits, starchy vegetables, grains, and legumes.
Foods that contain high amounts of sugar are also excluded, like candies, baked goods, sugary drinks, and desserts.
Instead, the ketogenic diet prioritizes foods that are low in carbs and high in fat, such as animal proteins, dairy products, non-starchy vegetables, and oils or butter.
The Mediterranean diet generally limits red meat, processed foods, and added sugar. Conversely, the keto diet is a more restrictive eating pattern that limits foods high in carbs or sugar, such as fruit, starchy vegetables, grains, legumes, and sweets.
Both the Mediterranean diet and ketogenic diet have been associated with several health benefits.
May support heart health
The Mediterranean diet is perhaps most well-known for its ability to support heart health.
For instance, one large review of 41 studies found that adherence to a Mediterranean diet was linked to a lower risk of heart disease and stroke (
Studies also show that the Mediterranean diet could help decrease blood pressure levels and protect against plaque buildup in the arteries, both of which can contribute to heart disease (
Research on the relationship between the keto diet and heart health has turned up mixed results. Some studies show that the keto diet could potentially reduce levels of total and low density lipoprotein (LDL or “bad”) cholesterol (
However, keep in mind that this may depend on several factors, and other studies have found that the ketogenic diet could actually increase levels of LDL cholesterol, which can contribute to the buildup of plaque in the arteries and block bloodflow to your heart (
The extent of the keto diet’s effects on heart health may also depend on the types of foods that you include in your diet, as many high fat ingredients often included in the diet — such as processed meats — are actually associated with an increased risk of heart disease (
Plus, some people’s bodies respond differently to dietary cholesterol, which may also have an effect on heart healt (
May support blood sugar management
The Mediterranean diet encourages a variety of nutrient-dense, high fiber foods, which could help stabilize blood sugar levels (
Research shows that the Mediterranean diet can improve blood sugar management and may be associated with a lower risk of developing type 2 diabetes (
The keto diet has also been shown to improve blood sugar management in people with type 2 diabetes (
According to one small study in 30 people with diabetes, 26% of those who followed a very low calorie keto diet for 12 months were able to stop taking all diabetes medications (
Both diets may help support insulin sensitivity as well. In fact, one study found that both a Mediterranean diet and low carb diet were similarly effective at reducing insulin resistance, a condition that impairs the body’s ability to regulate blood sugar levels (
However, the low carb diet in the study was about 30% carbs, which is much higher in carbs in a typical keto diet. Therefore, it’s unclear how much benefit, if any, the the keto diet may offer when it comes to supporting insulin sensitivity.
May support healthy brain function
Some research suggests that the Mediterranean diet may help support brain health as you get older.
For instance, one study found that greater adherence to the Mediterranean diet was associated with decreased markers of cognitive decline and dementia in older adults (
Another study concluded that the Mediterranean diet could be linked to improved brain function and memory, as well as a reduction in symptoms of depression, in older adults (
The ketogenic diet has also been studied for its ability to enhance brain health.
In fact, the ketone bodies that are produced as an alternative source of energy on the keto diet may have neuroprotective properties and are even being studied for their ability to protect against conditions like Alzheimer’s disease (
What’s more, the ketogenic diet is also often used as a treatment for epilepsy.
According to one review, several variations of the keto diet have been used to prevent seizures since the 1920s and are considered an effective treatment for people who have epilepsy that doesn’t respond to medications (
The Mediterranean diet and keto diet may both be beneficial for brain function and blood sugar management. Both have also been shown to support heart health, though research on the effects of the keto diet has turned up mixed results.
Though both the Mediterranean diet and keto diet may offer several health benefits, there are a few potential downsides to consider for each diet as well.
Unlike many other diet plans, the Mediterranean diet doesn’t have any strict rules or regulations to follow.
While some people may enjoy the flexibility that this eating pattern offers, others may prefer structured diets that provide more detailed guidance.
The Mediterranean diet also encourages moderate consumption of red wine with meals.
Although red wine has been linked to several health benefits, some people may need to limit their alcohol intake, including those who are pregnant or have a history of alcohol use disorder (
Plus, because the Mediterranean diet promotes mostly whole and minimally-processed foods, it can be more expensive and time-consuming to follow than some other plans as well, which might be a key consideration for some.
The keto diet is much more restrictive than the Mediterranean diet and may be more difficult to follow, as it requires you to track your carb intake carefully.
Not only can tracking be stressful and time-consuming, but some research suggests that food logging could foster an unhealthy relationship with food and cause feelings of guilt, shame, anxiety, or inadequacy after eating (27,
The keto diet can also cause several side effects initially as your body adjusts, known as the “keto flu.”
Some of the most commonly reported side effects associated with the ketogenic diet include headache, nausea, fatigue, dizziness, and brain fog (
Though there are limited studies on the long-term safety or side effects of the ketogenic diet, some research suggests that it could increase your risk of fatty liver disease, constipation, and kidney stones (
Furthermore, careful planning is needed to ensure nutrient needs are met on the ketogenic diet, as it may also be linked to a higher risk of vitamin and mineral deficiencies (
Restrictive weight loss diets, including the keto diet, may also have negative effects on mental health and body image.
In fact, they could even contribute to disordered eating behaviors, including feeling fixated on food, ignoring feelings of hunger and satiety (fullness), and developing an unhealthy obsession with healthy eating (
The Mediterranean diet isn’t structured, encourages some red wine, and may be expensive and time-consuming. The keto diet is restrictive, has side effects, and may increase your risk of nutritional deficiencies and other conditions.
Though there is no research comparing the effectiveness of the Mediterranean diet and ketogenic diet directly, both can help promote weight loss (
One study found that the Mediterranean diet resulted in up to 22 pounds (10 kg) of weight loss after one year and was as effective for weight loss as low carb and diabetes-friendly diets (
On the other hand, a small study in 32 people with obesity found that those who followed a low carb, low calorie diet lost 58% more body weight after 4 weeks than those who followed a low calorie Mediterranean diet (
However, keep in mind that both groups experienced similar reductions in belly fat and total fat mass. Additionally, the low carb diet was comprised of about 30% of daily calories from carbs, which is more than a traditional keto diet typically provides (
Still, while research shows that the keto diet may lead to rapid, short-term results, weight loss generally peaks after about five months and is not often sustained long-term (
Additionally, the ketogenic diet is also harder to stick to, and research on its long-term safety and effectiveness is lacking (
There is research, however, suggesting that diets moderate or low in carbs, but higher in carbs than keto, are easier to stick to than keto and result in similar amounts of weight loss (
Conversely, studies show that greater adherence to the Mediterranean diet could help prevent increases in body weight or belly fat in the long run (
Interestingly, one study comparing the effects of low fat, low carb, and Mediterranean diets even found that the Mediterranean diet was associated with the greatest adherence and most sustained weight loss among all three diets after six years (
Therefore, because it’s easier to follow, more flexible, and linked to a long list of health benefits, the Mediterranean diet is likely a better option than the keto diet for supporting long-term, sustainable weight loss (
For best results, be sure to pair a well-rounded and nutritious diet with a healthy lifestyle and regular physical activity.
Not only can this support steady weight loss that is easier to maintain in the long run, but it can also promote many other aspects of health while fostering a positive relationship with food and your body.
Though both the keto diet and Mediterranean diet can both promote weight loss, evidence suggests that the Mediterranean diet is safer, more sustainable, and more effective long-term.
The ketogenic (keto) diet and Mediterranean diet are two popular eating patterns that have been studied for their potential benefits.
In particular, both may help support heart health, blood sugar management, and brain function. However, some studies have found that the keto diet may increase levels of LDL cholesterol, so it may not be as effective at supporting heart health.
While both diets can also promote weight loss, the Mediterranean diet is easier to follow and is likely a safer, more sustainable option in the long run. Weight loss on the keto diet is likely to peak after a few months and is often not maintained over time.