Nutrition and diet

Mediterranean diet

Also called: Med diet, Mediterranean eating pattern

The Mediterranean diet is an eating pattern based on what people in southern Italy, Greece, and Spain traditionally ate: lots of vegetables, fruit, legumes, wholegrains, olive oil, fish, modest dairy and wine, and very little ultra-processed food. It has the strongest evidence of any single eating pattern for cardiovascular disease, dementia, type 2 diabetes, and overall mortality. Also one of the best diets for the gut microbiome.

What's in it

  • Vegetables: 5-7 servings a day. Tomatoes, onion, leafy greens, courgette, aubergine, peppers.
  • Fruit: 2-3 servings a day. Citrus, figs, grapes, berries, melons.
  • Legumes: 3+ times a week. Chickpeas, lentils, beans.
  • Wholegrains: bread, pasta, rice, bulgur, polenta.
  • Olive oil: the main fat for cooking and dressings, 30-50 ml a day.
  • Fish and seafood: 2+ times a week. Sardines, mackerel, salmon, prawns.
  • Nuts: a small handful most days. Walnuts, almonds, hazelnuts.
  • Eggs: 2-4 a week.
  • Cheese and yoghurt: moderate amounts most days.
  • Red meat: rare. 1-2 times a month.
  • Wine: optional, 1 glass a day with meals at most.
  • Sweets and ultra-processed food: rare.

Why the evidence is so strong

The PREDIMED trial randomly assigned 7,447 people at high cardiovascular risk to either a Mediterranean diet supplemented with extra virgin olive oil, the same diet supplemented with mixed nuts, or a low-fat control diet. After 5 years, both Mediterranean groups had about 30 percent fewer major cardiovascular events than the control. Subsequent observational studies show similar reductions in dementia, type 2 diabetes, and all-cause mortality across populations on the diet. No other eating pattern has this depth of randomised evidence.

Why your gut likes it

  • 30-40 g of fibre a day from vegetables, legumes and grains feeds butyrate-producing bacteria.
  • Polyphenols from olive oil, berries, herbs and red wine selectively feed Akkermansia and Bifidobacterium.
  • Fermented foods (yoghurt, some cheeses) add live microbes.
  • Modest fish intake provides omega-3, which modulates the gut barrier.
  • Almost no ultra-processed food, which is the main driver of microbiome impoverishment in modern diets.

The simple version (if you don't want a meal plan)

  1. Olive oil instead of butter or seed oils for most cooking.
  2. Vegetables on every plate, half the plate where possible.
  3. Beans or lentils 3 dinners a week.
  4. Fish twice a week, one of which is oily (sardines, mackerel, salmon).
  5. Wholegrain bread or pasta, not white.
  6. A handful of nuts at lunch or as a snack.
  7. Fruit for dessert most days, sweet treats occasional.
  8. Water as your main drink.
  9. Walk after meals.
  10. Don't sweat the precise ratios. Pattern matters more than purity.

Common questions

Can you do the Mediterranean diet without fish?
Yes. Vegetarian and pescetarian variants both work. Replace fish with extra legumes, nuts, eggs and a high-quality omega-3 supplement (algae-based for vegans). The benefits remain, though slightly attenuated without fish.
Is olive oil really that important?
Yes, in PREDIMED both Mediterranean arms had olive oil but the extra-virgin olive oil arm had measurably better outcomes. The polyphenols in extra virgin (oleocanthal, oleuropein) are the active part. Refined or 'pure' olive oil has most of these stripped out. Look for 'extra virgin' and a recent harvest date.
How does it compare to keto or paleo?
Mediterranean has by far the strongest cardiovascular and longevity evidence. Keto can produce faster weight loss short-term but compliance drops sharply at 12+ months. Paleo eliminates legumes and grains, both of which feed gut bacteria the Mediterranean diet relies on. For sustainable lifelong eating, Mediterranean wins on the data.
Is wine really part of the diet?
Optional and often overstated. The cardiovascular benefit attributed to wine is small once you control for healthy lifestyles overall. UK guidance has shifted to 'no alcohol is the safest level for cancer risk'. If you don't drink, don't start. If you do drink, 1 glass with food is the version that fits the pattern.

Sources