Insulin resistance diet: Mediterranean vs low-carb vs keto – what actually works?

“Which diet should I choose for insulin resistance?” is one of the most common questions in my consultations. The Mediterranean, low-carb and ketogenic approaches all have solid evidence, but their mechanisms and long-term fit differ. Here is what the research says about who benefits from what.

Why the diet choice depends on the stage of insulin resistance

Insulin resistance is not a binary diagnosis – it is a spectrum from mild compensatory hyperinsulinaemia to established type-2 diabetes. HOMA-IR 1.2 requires a different intervention than HOMA-IR 4.5. That is why there is no single “best” diet – there is a best diet for a specific person at a specific metabolic stage.

Mediterranean diet: widest evidence base and best long-term adherence

PREDIMED (Estruch, NEJM 2018) showed a 30% reduction in cardiovascular events, and a sub-analysis (Salas-Salvadó, Diabetes Care 2011) a 52% lower incidence of type-2 diabetes. Mechanism: high polyphenol intake (olive oil, berries, fish), omega-3, high fiber, low ultra-processed food share.

• Carbs ~40–45% of energy, mostly legumes and whole grains
• Olive oil as primary fat (35–40% of energy), nuts, fatty fish 2–3× per week
• Red meat < 1–2× per week, poultry and eggs in moderation
• Easiest to sustain long-term – socially and culturally flexible

Low-carb diet: the best compromise

DIETFITS (Gardner, JAMA 2018) compared low-carb and low-fat diets – 12-month weight loss was comparable, but insulin sensitivity improved more in the low-carb group. Carbs at 20–35% of energy (~80–150 g/day), the body does not enter ketosis, but insulin load drops significantly.

• Carbs primarily from vegetables, berries, legumes
• Does not require the strictness of ketosis – socially flexible
• Fits most people with HOMA-IR between 1.5 and 3.5
• Metabolic flexibility is preserved – the body can use both glucose and fat

Ketogenic diet: strongest effect in more severe cases

Virta Health (Hallberg 2018; Athinarayanan 2019 – 2 years) reported 60% remission of type-2 diabetes, HbA1c dropping from 7.6 to 6.3%, and medication withdrawal in 57% of patients. Carbs < 20–50 g/day, the body enters ketosis, and average daily insulin drops dramatically.