What Is Insulin Resistance? Signs, Causes and How to Reverse It

November 09, 2023

What is insulin resistance, and should you be concerned?

Insulin resistance affects a significant proportion of adults, and most of them don't know it. It can quietly develop for years before any symptoms appear, which is exactly why it's worth understanding.

First, a quick look at how insulin works

Every time you eat carbohydrates, your body breaks them down into glucose, a simple sugar that travels through your bloodstream to fuel your cells. But glucose can't get into cells on its own. It needs a signal.

That signal is insulin, a hormone made by the pancreas. When blood glucose rises after a meal, insulin is released and essentially unlocks the door to your cells, letting glucose in to be used as energy or stored for later.

Insulin resistance is what happens when cells start ignoring that signal. They become unresponsive, so the pancreas compensates by producing more and more insulin to try to get the job done. This works for a while, but eventually blood glucose starts to creep up anyway. That's the trajectory from insulin resistance to prediabetes to type 2 diabetes.

What causes it?

Insulin resistance is rarely caused by one thing. It usually develops through a combination of factors over time.

Excess visceral fat, the fat stored deep around the abdominal organs, is one of the strongest drivers. It releases inflammatory chemicals that directly interfere with insulin signalling. Waist circumference is often a better early indicator of metabolic risk than overall body weight.

Physical inactivity reduces the muscles' ability to take up glucose. Muscle tissue is your body's biggest consumer of glucose, and regular movement keeps cells responsive to insulin, even without a formal exercise programme.

A diet high in refined carbohydrates and added sugar repeatedly spikes blood glucose and insulin, gradually wearing down the cells' response over time. Ultra-processed foods are particularly problematic because they combine refined carbohydrates, added sugars and industrial seed oils with almost no fibre, meaning glucose hits the bloodstream rapidly and repeatedly with nothing to slow it down.

Chronic poor sleep impairs insulin sensitivity measurably, even after just a few nights. Hormones regulated during sleep, including cortisol and growth hormone, play a direct role in glucose metabolism.

Ongoing stress keeps cortisol elevated, which raises blood sugar and works directly against insulin's effects.

Genetics play a role too. Some people have a higher predisposition regardless of lifestyle. But genes tend to load the gun; lifestyle largely determines whether it gets pulled.

Hormonal conditions such as PCOS, hypothyroidism and Cushing's syndrome are also strongly associated with insulin resistance, as are certain medications including corticosteroids and some antipsychotics.

The signs, and why they're easy to miss

This is the frustrating part. Insulin resistance itself usually has no symptoms in its early stages. It can be present for a decade before anything obvious appears.

As it progresses, some signals may emerge, though none of these are diagnostic on their own:

Persistent fatigue, even after adequate sleep
Strong sugar cravings or hunger shortly after eating
Brain fog, particularly after meals
Difficulty losing weight, especially around the belly
Dark, velvety skin patches in skin folds such as the neck, armpits or groin (known as acanthosis nigricans)
Skin tags on the neck, armpits, under the breasts and groin
Increased thirst and more frequent urination, which tends to appear once blood sugar has already started to rise

If any of these resonate, a simple blood test is the most useful next step. A fasting glucose, HbA1c or fasting insulin test can give you a clear picture. It's a routine test through your GP.

Can insulin resistance be reversed?

In most cases, yes, particularly when caught early. It's one of the more responsive conditions to lifestyle change, and you don't need to do everything perfectly. Consistent, moderate improvements across a few key areas make a genuine difference.

Move your body, especially after meals. Exercise is a powerful tool. Muscle contractions allow cells to take up glucose independently of insulin. Even a 10 to 15 minute walk after eating measurably blunts the post-meal glucose spike. Strength training is particularly effective for long-term insulin sensitivity.

Choose carbohydrates that release glucose slowly. The goal isn't necessarily to eliminate carbs; it's to choose whole, fibre-rich options like vegetables, legumes, nuts and seeds. These have a far gentler effect on blood sugar than refined bread, white rice or sugary drinks. Including protein and/or fat also slows glucose absorption.

Avoid ultra-processed foods. These products combine refined carbs, added sugars and inflammatory seed oils with almost no fibre, making them very effective at spiking blood glucose and driving metabolic damage to our cells through inflammation. Replacing them with whole, minimally processed foods is one of the most impactful changes you can make.

Prioritise sleep. A single night of poor sleep can reduce insulin sensitivity by around 25%. Consistently poor sleep is a meaningful driver of metabolic dysfunction. Seven to nine hours is foundational, not optional.

Reduce unnecessary snacking. Frequent eating keeps insulin elevated for more hours of the day. Allowing genuine gaps between meals, including a longer overnight fast of even just 12 hours, helps insulin levels settle and cells become more receptive again.

Manage ongoing stress. Cortisol raises blood sugar. Regular movement, adequate sleep and time spent doing things that genuinely help you unwind are direct inputs into your metabolic health, not just lifestyle extras.

Where whole foods fit in

Everything we make at Wholo Foods is built around real, whole ingredients such as: nuts, seeds, vegetables and healthy fats. The kinds of foods that support stable blood sugar rather than spiking it.

Our Amazeballs are based on nuts rather than dried fruit, making them much lower in sugar than most bliss balls. The Vanilla Bliss and Choc Cacao Crunch flavours have just 1g of sugar per ball. Our Seeded Crackers and Vitality Wraps are made without refined flour or additives and provide low carb and keto slow-release energy from whole food ingredients.

Our food is not a supplement or a shortcut. It's just good food, made the way food should be made.

Common questions

Is insulin resistance the same as diabetes? No. It's a precursor to type 2 diabetes, not the condition itself. Many people with insulin resistance never develop diabetes, particularly if they address it early. Think of it as a warning signal rather than a diabetes diagnosis.

How is insulin resistance diagnosed? Your GP can order a fasting blood glucose test, an HbA1c, or a fasting insulin test. If you have risk factors such as family history, PCOS, or weight gain around the abdomen, it's worth asking proactively.

What's the best diet for insulin resistance? The consistent evidence points toward plenty of vegetables, legumes, nuts and seeds; adequate protein at each meal; healthy fats; and minimal refined carbohydrates, added sugars and ultra-processed foods.

This article is for general health information only and does not constitute medical advice. If you have concerns about blood sugar or insulin resistance, please speak with your healthcare provider.

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Blog updated April 2026