Mediterranean diet: Benefits, heart health and weight loss

Mediterranean diet
Mediterranean diet

Healthy, delicious and adaptable, the Mediterranean diet is one of the very few diets that all the experts recommend.

This is partly because it’s not actually a diet, but a pattern of eating derived from the traditional foods and lifestyle found in countries such as Italy, Spain and Greece, which border the Mediterranean Sea. 

It’s been extensively researched, and that research has shown that it confers multiple health benefits, most notably protecting against heart disease.

The diet is so important that it has its own Unesco listing and can be found on the UN’s list of the Intangible Cultural Heritage of Humanity.

Yet don’t think that the Med diet comprises exactly the same foods as you’ll find in Italy, Greece and Spain on your summer holiday. Staples such as pizza, gelato, lasagne and moussaka, for example, are consumed only occasionally on the Med diet.

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What makes up the Mediterranean diet?

  • Lots of fruit and vegetables

  • Beans and pulses

  • Nuts and whole grains

  • Moderate amounts of seafood

  • Dairy

  • Eggs

  • Poultry and a limited amount of red meat

  • Occasional sweet foods

“Nutritionists differ slightly on how they define the Med diet, but the main dietary components are broadly the same and it can be adapted to multiple cuisines. It also moves with the times as experts are increasingly advising people to limit UPFs (ultra-processed foods),” says Richard Hoffman, an associate lecturer in nutrition at the University of Hertfordshire.

Ancel Keys, the researcher, coined the term Mediterranean diet in the Fifties after he noticed that southern Italy contained the highest concentration of centenarians in the world. Dr Antonia Trichopoulou, the Greek nutritionist and scientist, went on to develop the first standardised score, the Mediterranean Diet Score, which has been used in hundreds of research studies all over the world. Then in 1993, the non-profit organisation Oldways created a handy Mediterranean Diet Pyramid, in partnership with the Harvard School of Public Health and the World Health Organisation.

“The Med diet can include white pasta and grains on occasion, but within the pyramid, the biggest layer is for whole fruits and veg, pulses and legumes and nuts and seeds. Bread and pasta and cakes and sweets are included in the pyramid as occasional treats, but they are traditionally homemade, so there is a lot of focus on the quality of the food too,” says nutritionist Dr Federica Amati, a lecturer at Imperial College London and the author of the new book Every Body Should Know This.

Why choose the Mediterranean diet?

The Med diet is not only delicious and proven to be the healthiest way of eating, but its focus on vegetables, fruits and legumes is flexible and can be easily adapted to different national cuisines.

It’s not complicated to cook, and because almost everything is included it’s not overly restrictive either.

“You can recreate this eating pattern with any cuisine as every country has its indigenous plants and pulses so you can create the Med diet with foods that are local to you and in season. It works just as well for the south-east Asian and east African diets and with traditional British fruit and veg, for example,” says Dr Amati.

“The important thing is that on this diet you’re getting lots of fibre, lots of different biochemicals, healthy fats and nutrients that we need to feel our best and to reduce our risk of illness later in life,” says Dr Emily Leeming, a dietitian and microbiome scientist.

The diet is also about more than just food. When researchers studied the traditional eating patterns of people in Mediterranean countries, they observed that they were physically active most of the day and that their meals were leisurely and eaten with family and friends. At the bottom of the pyramid, then, is a recommendation to eat with others and be active.

“It’s not just the food, it’s the whole lifestyle. It’s important to sit down and eat with family and friends and spend a reasonable amount of time to allow the feeling of satiety to kick in,” says Hoffman.

Health benefits of the Mediterranean diet

Heart health

The evidence for the protective elements of the Med diet is compelling.

“Going back over 50 years, the Seven Countries Study found that dietary patterns in the Mediterranean were linked with lower rates of heart disease and death. The Lyon Diet Heart Study built on these findings – this clinical trial showed a striking protective effect on heart attack recurrence. Since then, large-scale trials have consistently shown compelling evidence on cardiovascular health including blood pressure and blood cholesterol,” says Dr Samantha Gill, a specialist gastroenterology dietitian.

Weight management

The primary focus of the Med diet is health rather than weight loss but if it’s followed correctly, studies have shown that it leads to a lower body weight and that people tend to keep the weight off long-term, as they can stick to the Med diet more easily than other weight loss diets.

Diabetes

As the Med diet is good for blood sugar control and weight management, it follows that it is also helpful for Type 2 diabetes. A review of studies in 2020 concluded that people who follow the diet are 20 per cent less likely to develop Type 2 diabetes than those who don’t follow the diet.

Mental health and longevity

In 2017, a landmark study, the Smiles Trial, showed that the Med diet had a powerful effect on depression.

“This study took people with moderate to severe depression – one group followed a Mediterranean-style diet and the other group did not. The diet included an impressive 50g of fibre per day. The results showed those in the Mediterranean-style group had a much greater reduction in depressive symptoms. In fact, 32 per cent in the diet group compared to 8 per cent in the control group were classified as no longer depressed,” says Dr Gill.

Other studies have reported similar findings and the diet is also linked to a lower risk of dementia and Alzheimer’s disease.

“At the base of the Med diet pyramid is eating socially with loved ones and a physically active lifestyle. We know that social contact and physical activity lead to better health outcomes and a longer life,” says Dr Amati.

Pregnancy and fertility

New research has linked the anti-inflammatory foods in the Med diet to improvements in fertility. Studies have also shown that eating the Med diet when pregnant also leads to healthier outcomes in children.

Frailty in older people

Studies have shown that following the Med diet can help improve and prevent frailty in older people.

Autoimmune conditions

Several studies have shown that the Med diet is anti-inflammatory and can help ease symptoms of autoimmune diseases such as psoriasis, rheumatoid arthritis and inflammatory bowel diseases.

Cancer

A 2017 review of studies showed that the Med diet may help reduce the risk of several cancers, potentially because it reduces weight gain and obesity, which is linked to many cancers.

Gut health

Research has shown the Med diet can increase gut microbiome diversity and lead to a higher abundance of certain bacterial species.

Key foods and ingredients

  • Most of the diet should be made up of plants (for example fruits, vegetables, whole grains, legumes, nuts and seeds) which contain fibre and plant chemicals (such as polyphenols)

  • Healthy fats such as monounsaturated fats from extra virgin olive oil and polyunsaturated fats (such as omega-3) from oily fish, nuts and seeds

  • Lean proteins such as fish and to a lesser extent poultry

  • Limited amounts of dairy, particularly fermented dairy such as yogurt and cheese

  • Red wine, in limited amounts with food

“How you cook the food is also important. Meat is cooked mainly in stews, which reduces the production of carcinogens from high-temperature frying, and vegetables tend to be cooked in olive oil, which helps the body absorb the nutrients,” says Hoffman.

Fruits and vegetables

Fruits and vegetables are very nutrient-dense, and consuming a wide variety means we ensure we get all the nutrients and biochemicals we need for our health.

“With the Med diet we don’t have the traditional meat and two veg; the hero ingredients are the fruit and veg, so it’s about making sure you’re having a wide variety of fruit and vegetables and bringing them to the forefront of your diet,” says Dr Amati.

And our choice of fruit and veg doesn’t have to be based on typically Mediterranean varieties – we can choose whatever is in season and local to us.

Whole grains and fibre sources

The Med diet is rich in whole grains and sources of fibre such as nuts, seeds, beans and pulses.

“We are understanding more and more what a vital role fibre plays in the health of our gut microbiome and whole grains and legumes, like rye bread and chickpeas, for example, tend to be higher in fibre than fruit and veg,” says Dr Leeming.

Proteins: fish, poultry and plant-based options

Fish contains omega-3, which is important for our brain development.

“Omega-3 is instrumental for our brains, mood and cognition, and in the UK and the US we have some of the lowest-circulating levels in our blood of omega-3. You can find omega-3s in plant sources too like flaxseeds, chia seeds and walnuts, but in plants it is harder to convert into the type of omega-3 DHA that we need for our brain, so if you’re not a fish eater I do tend to recommend a supplement,” says Dr Leeming.

Sardines on toast
Oily fish like sardines are rich in omega-3 which is crucial for brain health - Getty

We need sufficient protein and good lean sources include poultry and beans, chickpeas, nuts and lentils. Red meat, which is high in saturated fat, is limited to an occasional treat.

Healthy fats: nuts, seeds, and oils

Healthy unsaturated fats that lower the risk of heart disease and stroke are found in nuts, seeds and extra virgin olive oil.

“The most important component of the Med diet is extra virgin olive oil,” says Hoffman. “It’s a shame it has got so expensive as it contains compounds that aren’t present in any other food source and are particularly beneficial and protect against some cancers.

“Buy extra virgin olive oil produced from a cold pressing, where they squeeze the oil from the olives, preserving the antioxidants and phytochemicals. If it’s not extra virgin olive oil, then it’s made from the mash after the first pressing has been done, and they take that mash and heat it and use chemicals to extract more oil, and this destroys all the goodness.”

What about dairy and alcohol?

The Med diet includes dairy in moderate amounts, but the emphasis is on fermented dairy products such as yogurt and aged cheese as opposed to drinking much milk.

“Dairy is high in the unhealthy kind of fat, saturated fat, but we think because it has bacteria that it helps to feed our gut – that gives it a neutral profile when it comes to our cholesterol levels,” says Dr Leeming.

Red wine also features on the Med diet pyramid, but in a social setting while eating a meal. It’s not compulsory and won’t suit everyone, but there is some research linking red wine to health benefits, although other studies show the risks of drinking alcohol outweigh the benefits.

“It’s consumed with a meal, and in moderate quantities – there is no binge drinking on an empty stomach. It contains antioxidants, most of which are polyphenols, which have a role in protecting against heart disease and dementia,” Hoffman explains.

Desserts and white carbohydrates

Experts recommend eating whole grains, brown rice, pasta and bread over the white alternatives that contain much less fibre. If you choose to have the white options, eat them in moderation and in small portions, and avoid highly processed foods such as mass-produced sliced bread in a plastic wrapping. 

Sweets and desserts should be consumed sparingly, and be homemade rather than industrially produced. Dark chocolate has been shown to have some health benefits.

Tips for preparing Mediterranean meals

  • Start slowly and easily to make a sustainable change that lasts. Make half your plate vegetables and add some flavour with herbs.

  • Eat beans and legumes 3-4 times a week.

  • Make time to cook and connect with others over food – it’s a stress reliever and is important for our health.

  • Focus on healthy fats, cook with olive oil, eat nuts and seeds as a snack, include avocado and oily fish.

  • Switch in plants to your regular dishes – swap out 50 per cent of the meat in lasagne and spaghetti Bolognese to include lentils, chickpeas or butter beans.

  • Go for variety instead of single packets – mixed veg, mixed nuts and mixed fruit.

  • Snack ideas include: carrots with hummus, a piece of fruit or handful of dried fruit, Greek yogurt with a drizzle of honey, apple slices with nut butter.

  • Try having red-meat-free days – opt for fish or poultry instead.

  • Fruit and vegetables don’t have to be fresh to count – dried, tinned (in natural juices/water) and frozen all count.

Tips from Dr Emily Leeming and Dr Samantha Gill