Insulin resistance: The metabolic early warning sign

Dr. Charalampos Romanos · April 14, 2026 · 5 min read

Insulin resistance is the silent precursor to type 2 diabetes. Many people already have insulin resistance without knowing it. That's the insidious part: there are no strong symptoms that drive you to the doctor — until it's too late and diabetes breaks out. In my Zurich practice, I see insulin resistance as one of the most important early disease markers.

What is insulin resistance anyway?

Normally we eat carbohydrates, blood sugar rises, the pancreas releases insulin, insulin binds to insulin receptors on cells, and cells take up glucose. But with insulin resistance, this process doesn't work. The cells don't "listen" to the insulin. The pancreas produces more and more insulin to achieve the same effect. This is energetically very expensive and is not sustainable.

The symptoms you should know about

Uncontrolled craving for sugar or carbohydrates, especially in the afternoon. Energy drop after eating. Weight gain, especially around the belly. Wounds that heal poorly. Dark skin patches (acanthosis nigricans). Many people with insulin resistance also have high blood pressure and abnormal blood lipids. It's a whole cluster of problems.

The HOMA index: The simple diagnostic tool

HOMA stands for Homeostasis Model Assessment. The index is calculated from fasting blood glucose and fasting insulin: HOMA = (Glucose × Insulin) / 405. An HOMA > 2 suggests insulin resistance. This is a simple, inexpensive test that provides a lot of information. I always order this in patients with risk factors.

Why standard blood sugar testing isn't enough

A normal fasting blood sugar says nothing about insulin resistance. The fasting blood sugar can be normal while the person is already severely insulin-resistant. The insulin level just gets higher and higher to keep glucose in the target range. An oral glucose tolerance test (OGTT) is more informative, especially with insulin measurements in it.

Lifestyle changes that work

The good news: insulin resistance can be reversed. A low-carb or low-GI diet is fundamental. But also exercise — especially resistance training — increases insulin sensitivity. Adequate sleep is necessary. Stress reduction is important because cortisol worsens insulin resistance.

Supplementation and medical support

In my functional medicine I use berberine, inositol, chromium, magnesium — all of these improve insulin sensitivity. With severe insulin resistance, metformin can be helpful. The goal is not just to control blood sugar — the goal is to heal insulin resistance so the pancreas can relax again.