Understanding Insulin Resistance
Insulin Resistance: Why the Diagnosis Alone Isn't Enough
Almost every client who tells me their provider said they are insulin resistant or have "insulin resistance" follows up with the same question: "Okay, but what does that mean?" It's a fair question. Most of them left the appointment with a diagnosis and no explanation or help on how to manage it, so they turn to Google or AI and find so many different responses that they are scared and overwhelmed. This post is the explanation I want them, and you, to have.
Researchers know a lot about insulin resistance, and the basics are well established (1). Once you see how it works, deciding what to do next gets easier.
This post walks through how your body handles blood sugar, what changes with insulin resistance, and what the research says about food, exercise, and weight.
The Basics: How Insulin and Glucose Work Together
To understand insulin resistance, you need to know how it's supposed to work. When you eat, your body breaks carbohydrates (bread, pasta, oats, fruits, sugar, etc.) down into glucose, a simple sugar that fuels your cells (2). That glucose then enters your bloodstream, which is why your blood sugar rises after a meal. But glucose can't get into your cells on its own. It needs a key to unlock the door, and that key is insulin (2).
Insulin is a hormone made by your pancreas. Its main job is to help glucose move out of your blood and into your muscles, fat, and liver, where it can be used for energy right away or stored for later (2). Once glucose enters your cells, your blood sugar levels return to a normal range, and the cycle resets until your next meal (2).
When glucose and insulin work together, this process runs smoothly. Your pancreas releases the right amount of insulin, your cells respond to it, and your blood sugar stays balanced without you thinking about it. Insulin resistance happens when a step in this process stops working as it should.
Understanding Insulin Resistance
Insulin resistance means your body is still making insulin, but the key isn't opening the door (2). Insulin shows up, but your muscles, fat, and liver cells don't respond to it, so glucose has a harder time getting from your blood into your cells (2).
Your pancreas responds by producing more insulin to compensate (2, 3). This buildup of higher-than-normal insulin in your blood is called hyperinsulinemia (2).
At first, this can work. Your pancreas can make enough extra insulin to keep your blood sugar in a healthy range so that you won't notice anything different day to day (2, 3). But this workaround has limits. Over time, especially in people who are susceptible, the pancreatic beta cells may no longer be able to produce enough insulin to compensate (2, 3). When that happens, your body can't make enough insulin to keep up, blood sugar levels rise, and it becomes harder to bring them back down. This state is called hyperglycemia (2, 3). And left unaddressed, it can lead to prediabetes and type 2 diabetes (1, 3).
What Causes Insulin Resistance
Insulin resistance isn’t caused by one thing; it's usually a combination of risk factors that, together, raise your likelihood of developing it (2, 3):
Carrying extra body fat, especially around your belly (2, 3)
Not getting much physical activity (2, 3)
Eating patterns high in processed foods and refined carbs (2, 3)
Certain medications, like steroids (2)
Family history of prediabetes, type 2 diabetes, or PMOS (formerly known as PCOS) (2)
Hormonal conditions like Cushing's syndrome, acromegaly, or hypothyroidism (2)
Rare genetic syndromes (2, 3)
Age, ethnicity, and having sleep apnea (2)
Common Signs and Symptoms
Insulin resistance often has no symptoms, especially early on (2, 3). As long as your pancreas can keep up by making extra insulin, your blood sugar stays balanced, and you won't feel any different, as I mentioned before (2, 3). But when signs do show up, they can include:
Darkened, thickened or velvety skin, particularly around the neck, armpits or groin, called acanthosis nigricans. Skin tags may also occur more commonly in people with insulin resistance (2, 3)
Increased thirst
Frequent urination
Fatigue
Blurred vision (2)
How Insulin Resistance Is Diagnosed
There’s a test called HOMA-IR that uses your fasting blood sugar (glucose) and insulin levels to estimate how well your body responds to insulin (3). But this test isn't part of routine care. Most healthcare professionals don't order it unless there's a specific reason to (1, 3).
There is no single routinely used clinical test that definitively diagnoses insulin resistance. Fasting insulin and glucose can be used to calculate HOMA-IR, but interpretation varies because there is no universally accepted cutoff. Standard tests such as fasting glucose, A1C and an oral glucose tolerance test are primarily used to identify abnormal glucose regulation, prediabetes and diabetes. These values can still be normal during earlier insulin resistance because the pancreas may compensate by producing more insulin. And they may also order a lipid panel, which checks the fats in your blood (2). The most common blood sugar tests are:
A1C test → measures your average blood sugar over the past two to three months (4):
Normal: below 5.7%
Higher than normal: 5.7% to 6.4%
Fasting glucose test → checks your blood sugar after not eating for at least 8 hours (4):
Normal: below 100 mg/dL
Higher than normal: 100 to 125 mg/dL
Oral glucose tolerance test (OGTT) → checks your blood sugar before and two hours after drinking a sugary drink. After two hours (4):
Normal: below 140 mg/dL
Higher than normal: 140 to 199 mg/dL
Random plasma glucose test → a blood sugar check at any time of day, used when you already have classic signs and symptoms of high blood sugar (4):
Signals a concern: 200 mg/dL or higher
Your provider may also consider patterns in your lipid panel, such as elevated triglycerides, low HDL cholesterol, or the triglyceride-to-HDL ratio. These can provide additional clues about metabolic health, but they do not diagnose insulin resistance on their own.
Results in these higher ranges indicate impaired glucose regulation and may reflect progression from insulin resistance toward prediabetes or diabetes.
Managing Insulin Resistance
Research shows certain lifestyle changes can help manage and reduce insulin resistance and lower your risk of progression (2, 3). But not everyone with insulin resistance develops prediabetes or type 2 diabetes; however, most people with those conditions do have insulin resistance (1, 2).
Research points to three main areas that you can focus on to improve how your body responds to insulin (1, 3, 5):
Movement
Weight loss
Diet
1. Movement: What the Research Shows
Movement is one of the most effective tools for improving how your body responds to insulin (5, 3).
A research study followed adults with type 2 diabetes for 12 weeks, and they divided participants into two groups. One group added a structured exercise program that consisted of walking and strength exercises on top of their standard care. The other group continued with standard care alone (5). After 12 weeks, the exercise group's HOMA-IR (the insulin resistance test mentioned earlier) dropped by 30% (this is good). Meanwhile, the group that didn't exercise saw their HOMA-IR rise by nearly 15% (5).
Exercise helps manage insulin resistance in two main ways:
Makes your cells more responsive to insulin, a concept researchers call insulin sensitivity.
Builds muscle that can absorb and use blood sugar directly, without needing insulin's help at all (1, 3).
The exercise plan in this study wasn't extreme. Participants started slow and worked their way up to about 30 to 45 minutes of walking most days of the week, plus simple strength exercises (5). It was consistency that made the difference, not intensity.
What does this look like in real life? The American Diabetes Association recommends aiming for at least 150 minutes of moderate-to-vigorous aerobic activity per week, along with two to three resistance-training sessions on nonconsecutive days (6). This is an easy target to hit because you don’t have to do it all at once. Break it into smaller chunks, like 30 minutes five days a week, or even three 10-minute sessions spread throughout your day (6).
2. Weight Loss and Insulin Resistance
Weight loss helps manage insulin resistance, especially when extra fat is stored around the belly (2, 3).
In the landmark Diabetes Prevention Program, an intensive lifestyle program that targeted at least 7% weight loss and 150 minutes of physical activity per week reduced the risk of developing type 2 diabetes by 58% (3, 4). For someone who weighs 200 pounds, a 7% weight-loss goal is about 14 pounds.
Losing weight helps because it reduces the amount of fat stored in and around organs like your liver and muscles, the same fat that gets in the way of insulin's signal (2, 3). Less of that fat means your cells can respond to insulin more easily.
Losing weight through extreme measures can hurt you more than help you. Fad diets, skipping meals, and cutting calories too fast can all work against you instead of helping your blood sugar. If you want to lose weight, seek support from a healthcare professional who can help you do it safely (2, 3).
3. Eating for Insulin Resistance: Foods to Focus On
Food directly affects how your body handles blood sugar. Some foods cause a fast, sharp rise in blood sugar, which means your pancreas has to release more insulin at once. Other foods cause a slower rise, meaning your body needs less insulin to keep up (7).
The Mediterranean diet has strong research backing for managing insulin resistance (7). Here's what that diet prioritizes:
Plenty of vegetables, fruits, whole grains, beans, nuts, and seeds
Fish and seafood as a regular protein source
Olive oil as the main source of fat
Dairy, mostly yogurt and cheese, in moderate amounts
Red meat and sweets kept to a minimum
If you're interested in this diet, check out our cooking demos in the Teaching Kitchen. All classes are built around a Mediterranean diet framework.
This diet helps for the following reasons:
Fiber: Whole grains, vegetables, fruit, and beans are all high in fiber, which slows digestion. This means glucose enters your bloodstream more gradually instead of all at once, giving your body time to keep up rather than releasing a flood of insulin (7).
Limited added sugar: Foods and beverages high in added sugars and refined carbohydrates can make it easier to consume large amounts of rapidly absorbed carbohydrate with relatively little fiber. Reducing sugary drinks, sweets and highly refined foods can therefore make blood-sugar management easier (7).
Type of fat: Mediterranean-style eating emphasizes unsaturated fats from foods such as olive oil, nuts, seeds and fish while limiting processed meats and foods high in saturated fat. This pattern supports both cardiovascular and metabolic health (7).
The Mediterranean diet is adaptable and has plenty of room for flexibility. You don't have to strictly follow the Mediterranean diet, or give up the foods and traditions that matter to you entirely to manage this condition. The core ideas of the diet are: plenty of whole plant foods, lean proteins, healthy fats, and less added sugar, which can be applied to almost any style of cooking or cultural cuisine (8).
Building a Plan That Works for You
Movement, weight loss, and dietary changes each help your body respond to insulin the way it was meant to, but they're even more powerful together.
No blog post can replace a plan built around your specific situation, especially when it comes to nutrition. Your body, your lifestyle, and your health history shape what will work for you, and insulin resistance is no exception (2, 3). That's why working with a healthcare professional matters. They track your labs, adjust the plan as you progress, and help you implement what you learn.
If you're ready for guidance built around you or are looking to support someone you love, nutritionist Caitlin and I are glad to help. We offer 1:1 sessions where we go beyond what any blog post or internet search could ever cover. We’ll build a plan that fits you.
Check out our nutritional counseling services here.
You've walked through what insulin resistance is, how it develops, what the research shows about managing it through exercise, weight loss, and eating patterns, and why a personalized plan matters. Below is a reference section for when you need it.
Glossary: Common Terms to Know
A1C: A blood test that measures your average blood sugar over the past two to three months (4).
Acanthosis nigricans: Darkened patches of skin, often found in the armpits, neck, or groin, that can be a sign of insulin resistance (2, 3).
Beta cells: The cells in your pancreas that produce insulin. Insulin resistance can cause these cells to wear out over time from producing extra insulin (2, 3).
Fasting glucose: A blood sugar test taken after not eating or drinking anything except water for at least 8 hours (4).
Glucose: A simple sugar that comes from the food you eat and serves as your body's main source of energy (2).
HOMA-IR: A test that estimates insulin resistance using your fasting blood sugar and fasting insulin levels. It's mainly used in research rather than routine care (3).
Hyperglycemia: Elevated blood sugar levels, which can happen when insulin resistance progresses without enough insulin to keep up (2).
Hyperinsulinemia: Having higher-than-normal levels of insulin in your blood, often because your pancreas is producing extra insulin to make up for insulin resistance (2).
Insulin: A hormone made by your pancreas that helps glucose move out of your blood and into your cells for energy or storage (2).
Insulin resistance: A condition where your muscles, fat, and liver cells don't respond to insulin the way they should, making it harder for glucose to move from your blood into your cells (2).
Insulin sensitivity: How responsive your cells are to insulin. Higher insulin sensitivity means your cells use insulin efficiently, while insulin resistance reflects lower sensitivity (1, 3).
Oral glucose tolerance test (OGTT): A test that checks your blood sugar two hours after drinking a sweet liquid often called Glucola, showing how your body handles sugar (4).
Prediabetes: Blood sugar levels that are higher than normal but not yet high enough to be diagnosed as diabetes (1, 4).
Triglyceride/HDL ratio: A ratio sometimes used as an additional marker for insulin resistance, calculated from your triglyceride and HDL cholesterol levels (3).
FAQs
Q: Is insulin resistance the same as diabetes?
A: No. Insulin resistance is often what happens before prediabetes or type 2 diabetes develops, but having it doesn't mean you have diabetes (1, 2). Many people manage this condition for years without their blood sugar ever reaching diabetic levels.
Q: Can insulin resistance be reversed with diet and exercise?
A: Yes. Insulin sensitivity can often improve substantially with physical activity, weight loss when appropriate, dietary changes and treatment of contributing conditions (9).
Q: How is insulin resistance diagnosed?
A: There's no single test for insulin resistance used in routine care. Providers typically rely on standard blood sugar tests, like A1C and fasting glucose, along with your symptoms and family history, to get the full picture (2, 4).
Q: What foods help with insulin resistance?
A: Foods high in fiber, like whole grains, vegetables, fruit, and beans, along with lean protein and healthy fats, all help keep blood sugar rises slow and steady (7). Added sugar and refined carbs tend to work against this goal.
In health,
Keri Connell, CNS, LDN, IFNCP
Licensed Nutritionist & Cooking Instructor
References:
American Diabetes Association. (2024b). Understanding insulin resistance | ADA. Diabetes.Org. https://diabetes.org/health-wellness/insulin-resistance
Cleveland Clinic. (2021). Insulin resistance: What it is, causes, symptoms & treatment. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/22206-insulin-resistance
Freeman, A. M., & Pennings, N. (2023, August 17). Insulin resistance. StatPearls Publishing. Nih.Gov. https://www.ncbi.nlm.nih.gov/books/NBK507839/
American Diabetes Association. (2023). Understanding diabetes diagnosis. American Diabetes Association. https://diabetes.org/about-diabetes/diagnosis
Amaravadi, S. K., Maiya, G. A., K., V., & Shastry, B. A. (2024). Effectiveness of structured exercise program on insulin resistance and quality of life in type 2 diabetes mellitus–a randomized controlled trial. PLOS ONE, 19 (5), e0302831. https://doi.org/10.1371/journal.pone.0302831
American Diabetes Association Professional Practice Committee for Diabetes. (2026). Facilitating positive health behaviors and well-being to improve health outcomes: Standards of Care in Diabetes—2026. Diabetes Care, 49(Supplement_1), S89–S119. https://diabetes.org/health-wellness/fitness/weekly-exercise-targets
Cleveland Clinic. (2025, June 12). Foods to eat on an insulin resistance diet. Cleveland Clinic. https://health.clevelandclinic.org/insulin-resistance-diet
American Diabetes Association. (2024a). Eating for diabetes management | ADA. Diabetes.Org. https://diabetes.org/food-nutrition/eating-for-diabetes-management
Centers for Disease Control and Prevention. (2024, May 15). About insulin resistance and type 2 diabetes. CDC. https://www.cdc.gov/diabetes/about/insulin-resistance-type-2-diabetes.html