Feeling Off? It Could Be Insulin Resistance. Let's Explore the Signs.

Direct answer: Insulin resistance occurs when your body's cells don't respond well to insulin, leading to higher blood sugar levels. Early symptoms are often subtle and can include persistent fatigue, especially after meals, intense cravings for sugar or carbs, and unexplained weight gain, particularly around the abdomen. Other signs may include frequent urination and skin changes like dark patches (acanthosis nigricans) or skin tags. These symptoms often precede a diagnosis of prediabetes or type 2 diabetes.

TL;DR Insulin resistance is a condition where your body's cells struggle to use insulin effectively, forcing your pancreas to produce more to keep blood sugar in check. Over time, this can lead to prediabetes and type 2 diabetes. While often silent in its early stages, several subtle symptoms can signal that your body is struggling with insulin regulation. Recognizing these signs early is key to making lifestyle changes that can reverse the condition and protect your long-term metabolic health.

• Persistent Fatigue: Feeling tired all the time, especially a crash after eating a carbohydrate-rich meal, can be a primary sign. This happens because your cells aren't getting the glucose they need for energy.
• Intense Sugar Cravings: When your cells resist insulin, they can't get enough glucose for fuel. This sends a signal to your brain that you need more energy, triggering powerful cravings for sugar and simple carbs.
• Abdominal Weight Gain: Insulin resistance is strongly linked to an increase in visceral fat, the type of fat stored around your organs in the abdominal cavity. A growing waistline is a significant red flag.
• Skin Changes: Look for the development of skin tags or dark, velvety patches of skin called acanthosis nigricans. These patches commonly appear in body folds like the neck, armpits, and groin.
• Increased Hunger and Thirst: Even after eating, you might feel persistently hungry (polyphagia). This is coupled with increased thirst and frequent urination as your body tries to flush out excess sugar.
• Brain Fog: Difficulty concentrating or feeling mentally fuzzy can be related to fluctuating blood sugar levels and cellular energy deficits caused by poor insulin signaling.

Want the full explanation? Keep reading ↓

Your Labs Look "Normal," But You Feel Awful?

So you got your lab results back. You’re looking at your fasting insulin number, and maybe your doctor said it’s “within the normal range.” But you don’t feel normal. You’re tired all the time, that weight around your middle won’t budge, and you find yourself craving sugar like crazy.

It’s incredibly frustrating to feel like something is wrong when the numbers say you’re fine. The good news is, you’re not imagining it. The problem might be that your "normal" insulin level isn't actually optimal, and it could be an early warning sign of insulin resistance.

What High Insulin Feels Like (Even When It's "Normal")

Insulin is a hormone that acts like a key, unlocking your cells to let glucose (sugar) in for energy. When you have insulin resistance, your cells start ignoring the key. In response, your pancreas works overtime, pumping out more and more insulin to force the glucose into your cells.

This state of high insulin, called hyperinsulinemia, can happen long before your blood sugar levels ever become abnormal. A [fasting insulin test is one of the best ways for detecting insulin resistance early], often years before it shows up as prediabetes.

Subtle Symptoms You Might Be Brushing Off

High insulin doesn't always shout; sometimes it whispers. If you're experiencing several of these, it’s a sign your body is struggling with its metabolic health.

• Constant Fatigue: Especially that "carb coma" feeling an hour or two after eating. Your body is working overtime to manage blood sugar, which is exhausting.
• Stubborn Belly Fat: High insulin is a fat-storage hormone. It specifically tells your body to store fat around your abdominal organs.
• Intense Sugar or Carb Cravings: Your cells are starving for energy (because the glucose can't get in easily), so they send powerful signals to your brain demanding a quick fix: sugar.
• Feeling "Hangry" or Shaky Between Meals: This is a classic sign of a blood sugar rollercoaster caused by insulin spikes and crashes.
• Skin Changes: You might notice new skin tags, especially on your neck or under your arms. Another sign can be acanthosis nigricans—dark, velvety patches of skin in body folds.
• Brain Fog: Feeling forgetful or having trouble concentrating? High insulin can contribute to inflammation that affects brain function.
• For women: Irregular periods or signs of high androgens (like acne or facial hair) can be linked to high insulin, as seen in PCOS.

The Problem with "Normal" Fasting Insulin Ranges

Here’s the part that confuses so many people. The standard laboratory reference range for fasting insulin is often very wide. A lab might say anything under 25 µIU/mL is “normal.”

However, many functional and integrative medicine doctors argue that this range is far too broad. They look for optimal levels, not just the absence of outright disease. While standard ranges are designed to catch late-stage problems, understanding [normal fasting insulin levels and their optimal ranges] can help you spot trouble much earlier.

A level of 15 µIU/mL might be flagged as "normal," but it's a sign your pancreas is already working much harder than it should be.

Fasting Insulin Reference Ranges

This table shows typical laboratory reference ranges. Remember, optimal levels are generally considered to be much lower (ideally under 10 µIU/mL, with many experts preferring under 5).

Why You Need to Act Now

Think of high fasting insulin as the smoke before the fire. It’s a clear signal that your body is under metabolic stress. If left unaddressed, this constant state of high insulin is a [precursor to type 2 diabetes] and is linked to a higher risk of heart disease, fatty liver disease, and even some cancers.

The key takeaway is this: Your symptoms are real. If your fasting insulin is in the double digits—even if it's "normal"—it's a sign that it's time to make some changes.

What Can You Do About It?

Don't panic! The best part about catching high insulin early is that it's often highly reversible with lifestyle adjustments.

1. Talk to Your Doctor (Again): Go back to your doctor armed with this information. Ask questions like, "I know my insulin is technically normal, but could it be contributing to my symptoms? What is an optimal level?"
2. Focus on Your Diet: Reduce your intake of sugar, refined carbohydrates (white bread, pasta, pastries), and processed foods. These foods cause the biggest insulin spikes.
3. Prioritize Protein, Fiber, and Healthy Fats: These nutrients help stabilize blood sugar and keep you feeling full, reducing cravings and the need for your pancreas to work so hard.
4. Move Your Body: You don't have to run a marathon. Even a 15-20 minute walk after meals can significantly improve your insulin sensitivity.
5. Get Enough Sleep: Poor sleep is a major driver of insulin resistance. Aim for 7-9 hours of quality sleep per night.

You know your body best. If you feel that something is off, keep digging until you find an answer that makes sense. Your fasting insulin level is a powerful clue that can help you reclaim your health.

Frequently Asked Questions

What is the most common cause of abnormal Insulin (Fasting) levels?

The most common cause of high fasting insulin is insulin resistance, which is primarily driven by diet and lifestyle factors. Diets high in processed foods, sugar, and refined carbohydrates force the pancreas to produce excess insulin. Other contributing factors include a sedentary lifestyle, chronic stress, poor sleep, and excess body fat, especially around the abdomen.

How often should I get my Insulin (Fasting) tested?

If you have risk factors for insulin resistance (like family history, obesity, or symptoms like fatigue and cravings), it's a good idea to get a baseline test. If your levels are high, your doctor may recommend re-testing every 3-6 months after you've made lifestyle changes to track your progress. For healthy individuals with no risk factors, testing every 1-2 years as part of a routine check-up can be a good proactive measure.

Can lifestyle changes improve my Insulin (Fasting) levels?

Absolutely. This is the most important thing to know. High fasting insulin is highly responsive to lifestyle modifications. Changes like adopting a low-carbohydrate diet, increasing physical activity (especially strength training and walking after meals), managing stress, and prioritizing sleep can dramatically improve your insulin sensitivity and lower your fasting insulin levels, often within a few months.