Understanding Fasting Insulin Test for Metabolic Health and Diabetes Prevention

Understanding Fasting Insulin Test for Metabolic Health and Diabetes Prevention

When thinking about your body's energy, food typically comes to mind. After food is processed, insulin helps move glucose from your blood into your cells for energy.

Understanding Fasting Insulin Test for Metabolic Health and Diabetes Prevention
Written By
Mito Team
April 2, 2025

A fasting insulin test measures the level of insulin in your blood after an overnight fast. This shows how efficiently your body manages insulin on its own. 

Knowing your fasting insulin levels is key. It gives insights into your metabolic health, often before you notice other symptoms. It signals early signs of insulin resistance that lead to type 2 diabetes. This easy test lets you take charge of your health and boost your energy.

What Is Insulin?

Insulin is a hormone made by your pancreas. When you eat food, especially carbohydrates, your blood sugar levels rise. In response, the pancreas releases insulin. This hormone tells your muscle, fat, and liver cells to take in glucose from the blood. 

This process lowers your blood glucose levels and provides energy to your cells. If your body doesn't produce enough insulin or if it doesn't work correctly, glucose remains in the blood. This can lead to health problems.

Insulin and Metabolic Health: When Things Go Wrong

Insulin and Metabolic Health

Your body needs the right amount of insulin to work well. Health problems occur when your insulin levels are too low, too high, or when your cells don't respond properly to insulin.

  • Low insulin: This often happens when your pancreas does not make enough insulin. It means glucose levels drop and can't reach your cells from your blood. This is also called hypoglycemia. 

Low insulin is usually caused by your immune system attacking your pancreatic cells. And if your blood glucose levels stay high, you could get type 1 diabetes. Symptoms include frequent urination, excessive thirst, unexplained weight loss, and fatigue.

  • Insulin resistance: This happens when your cells don’t respond well to insulin. The pancreas produces more insulin, raising your glucose levels (hyperglycemia). It raises your risk for type 2 diabetes. Risk factors include: 
  • Extra weight, especially around the belly
  • Not getting enough exercise
  • Family history
  • Certain medical conditions

Symptoms of insulin resistance can be subtle. They can cause fatigue, weight gain in the belly, dark skin patches or acanthosis nigricans, and increased triglycerides.

Insulin Resistance and Diabetes: An Overview

Insulin resistance is an important factor in the development of prediabetes and type 2 diabetes.

Prediabetes means your blood sugar levels are higher than normal but not high enough for diabetes. Insulin resistance is a warning sign. It shows you need lifestyle changes to prevent type 2 diabetes. In the US, more than 97.6 million people ages 18 and older have prediabetes.

Type 2 diabetes happens when the pancreas can't make enough insulin because your body is resistant to it. Chronic high blood sugar leads to heart disease, kidney damage, nerve damage, and vision issues. There are 8.7 million people in the US with undiagnosed diabetes.

What Is a Fasting Insulin Blood Test?

What Is a Fasting Insulin Blood Test?

The fasting insulin blood test checks how much insulin is in your blood after an overnight fast of 8 to 12 hours. This test shows how well your body is using insulin. A simple blood sample is needed to do this test. 

To prepare for an insulin fasting test, it’s important to fast overnight for accurate results. Your baseline level helps your doctor check your metabolic health. It also helps find any insulin resistance.

Understanding Fasting Insulin Levels

A normal fasting insulin level ranges from 2.6 to 24.9 μU/mL. However, doctors often recommend keeping it under 10 μU/mL. This helps reduce your risk of getting metabolic syndrome and type 2 diabetes.

Doctors also use the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) to test for insulin resistance. This method combines your fasting insulin and glucose levels to give a clear picture of your insulin health. 

Knowing your insulin fasting levels helps you make better lifestyle choices. Always discuss your results with your doctor, as they can provide guidance based on your health history and other tests.

How to Improve Insulin Levels

How to Improve Insulin Levels

To improve your fasting insulin levels, you should start with these lifestyle changes:

  • Balanced diet: Focus on whole foods. Include lean proteins, healthy fats, and complex carbohydrates. Limit processed foods, sugary drinks, and refined grains.
  • Regular exercise: Aim for at least 150 minutes of moderate aerobic exercise each week, and include strength training.
  • Weight management: Losing a little weight, especially around your belly, can boost your insulin sensitivity.  
  • Stress management: Chronic stress leads to insulin resistance. Use stress-reduction methods like meditation, yoga, or deep breathing.  
  • Adequate sleep: Try to get 7 to 9 hours of quality sleep each night. Poor sleep can disturb hormone balance and worsen insulin resistance.
  • Regular monitoring: Use a glucose meter to check your blood sugar levels, and keep up with all doctor appointments.
  • Talk to your doctor: Discuss any medications or supplements that can help keep your insulin levels healthy.

What This Means for You

Knowing your fasting insulin level helps you improve how your body uses insulin. This gives you control over your metabolic health. The fasting insulin test is a helpful tool to check your metabolic health. By making informed choices, you can support your body’s energy systems and promote long-term well-being.

Mito Health provides a fasting insulin test. This is part of our comprehensive lab test that checks over 100 biomarkers, including insulin. With a simple blood draw, you’ll get personalized health insights based on your results with our top doctors.

References

1. https://www.hopkinsmedicine.org/health/conditions-and-diseases/diabetes

2. https://www.cdc.gov/diabetes/php/data-research/index.html

3. https://medlineplus.gov/lab-tests/insulin-in-blood

4. https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis

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