Insulin resistance and the HOMA index

The HOMA index (Homeostatic Model Assessment) is a medical formula used to estimate insulin resistance and the function of the beta cells in the pancreas. In practice, it shows how well the body uses insulin to keep blood sugar within normal limits.

Formula:
HOMA-IR = (fasting insulin × fasting glucose) / 405
(insulin in µU/mL and glucose in mg/dL; with glucose in mmol/L, divide by 22.5)

A high HOMA index means the body needs more and more insulin to keep blood sugar under control. This can be a stage that comes before type 2 diabetes, although not everyone with insulin resistance develops diabetes. It often goes unnoticed because it usually causes no symptoms.

As a rough guide (there is no single agreed cut-off: results depend on the laboratory method used to measure insulin and on the population studied):

• under about 2: usually normal
• about 2 to 2.5: borderline
• above about 2.5: suggests insulin resistance

The HOMA index can show insulin resistance before blood sugar rises, but it is not a test for diagnosing diabetes or prediabetes: these are diagnosed with fasting blood sugar, HbA1c or a glucose tolerance test. Your doctor interprets HOMA together with these tests.

Insulin resistance usually causes no symptoms, so it is often found only through blood tests. Some people have signs that can go with it:

• Excess weight, especially around the waist
• Acanthosis nigricans: patches of darker, thicker skin on the neck or in the armpits, sometimes with small skin tags
• Irregular periods / polycystic ovary syndrome (PCOS) in women
• High blood pressure and high triglycerides, often with low HDL (“good”) cholesterol

Tiredness, sleepiness after meals, sugar cravings or morning headaches are common and have many causes; on their own, they do not show insulin resistance. If you have the signs above or risk factors, ask your doctor about checking your blood sugar.

Insulin resistance is influenced by a combination of metabolic, hormonal and behavioral factors.

The main triggers include:

• Excess weight, especially belly fat
• A diet high in sugar, refined flour and ultra-processed foods
• Not enough sleep (under 7 hours)
• A sedentary lifestyle
• Chronic stress: it raises cortisol, a hormone that works against insulin
• Genetic predisposition
• Thyroid and other hormonal disorders, especially in women
• Non-alcoholic fatty liver disease (hepatic steatosis)
• Drinking too much alcohol

Finding the right causes helps the doctor tailor the prevention and treatment plan, especially in the early stages.

Prevention rests on two main pillars: lifestyle and regular medical check-ups.

Tests your doctor may recommend:

• Fasting blood glucose
• Fasting insulin
• Glycated hemoglobin (HbA1c)
• Lipid profile (LDL, HDL, triglycerides)
• Liver enzymes (transaminases), to check the liver

Simple prevention steps:

1. At least 150 minutes of physical activity a week: it can reduce insulin resistance within 2-6 weeks.
2. Enough sleep, at regular times: sleeping 5-6 hours a night or less is linked to a higher risk of type 2 diabetes (about 1.3 times higher in a large analysis of studies).
3. Managing stress: breathing exercises, meditation, regular breaks.
4. Regular check-ups: every 6 or 12 months, depending on your risk.

Prevention is usually simpler and more effective than treatment.

Nutrition is one of the main tools for improving how your body responds to insulin. Losing 5-7% of your body weight, through diet and physical activity, reduces insulin resistance. In a large study (the Diabetes Prevention Program), in adults with prediabetes and excess weight, a lifestyle program aiming for at least 7% weight loss and at least 150 minutes of physical activity a week lowered the risk of developing type 2 diabetes by 58% over about 3 years.

Key principles:

• Cut down on refined carbohydrates (white bread, pasta, sweets, pastries)
• Eat more fiber (vegetables, leafy greens, seeds)
• Include protein at every meal (chicken, fish, eggs, tofu)
• Healthy fats: avocado, olive oil, nuts
• Fewer snacks: 3-4 hours between meals
• Low glycemic index (GI): combinations that keep blood sugar stable

Foods that fit well in an eating plan for insulin resistance:

• broccoli, cauliflower, zucchini
• salmon, sardines, trout
• eggs
• berries
• avocado
• walnuts and almonds
• chia and flax seeds
• green tea

Foods to avoid:

• sugary soft drinks
• store-bought juices
• fast food
• French fries
• sugary breakfast cereals
• pastries
• cookies, wafers, croissants

A personalized eating plan, made by a doctor who specializes in nutrition, can help lower HOMA values faster.

A high HOMA index does not automatically mean diabetes, but it is a major metabolic warning sign. The earlier you act, the lower the risk of complications such as:

• type 2 diabetes
• high blood pressure
• fatty liver
• cardiovascular disease
• chronic kidney disease
• peripheral neuropathy

What a specialist doctor can do for you:

• a complete metabolic assessment
• finding the cause of your insulin resistance
• a personalized nutrition plan
• advice on supplements, only when there is a medical reason for them (for example, a deficiency found in your tests)
• monthly follow-up of your progress
• coordinated care with specialists in nephrology, vascular surgery or nutrition, depending on complications

The HOMA index is a useful indicator of insulin resistance, and finding high values early can make the difference between prevention and progression to diabetes. With healthy eating, physical activity and regular medical check-ups, this condition can not only be controlled but, in many cases, reversed.

References

• Glycemic Index Database, University of Sydney (home of the international GI database)
• Romanian Society of Diabetes, Nutrition and Metabolic Diseases (SRDNBM) (in Romanian)
• Rodiabet, a professional medical platform (in Romanian)
• NIDDK: Insulin Resistance & Prediabetes
• Cleveland Clinic: Insulin Resistance
• Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care, 2004;27(6):1487-1495
• American Diabetes Association Professional Practice Committee. 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes 2025. Diabetes Care, 2025;48(Suppl 1):S86-S127
• Demay MB et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism, 2024;109(8):1907-1947
• Knowler WC et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. New England Journal of Medicine, 2002;346(6):393-403
• Cappuccio FP et al. Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. Diabetes Care, 2010;33(2):414-420