Today’s low-carb lesson, What Is Insulin Resistance And Hyperinsulinemia?

We are incredibly lucky to have Dr Catherine Crofts join us to explain these terms and why they are so important to understand to avoid future metabolic diseases.

Low-Carb Lesson – What Is Insulin Resistance And Hyperinsulinemia?

We discuss:

  • What is insulin resistance?
  • Hyperinsulinemia – why should we try to avoid it?
  • What is metabolic syndrome?
  • How does insulin affect signalling in the brain (and why this could be a breakthrough in neurodegenerative states)

What Is Insulin Resistance and Hyperinsulinemia? 

Diagram showing insulin resistant cellsImage credits: Dr Catherine Crofts.

When you eat/drink any digestible carbohydrate, it is turned into glucose in our body.

Normal cell: The body requires insulin to help facilitate the movement of glucose from the blood by attaching to the insulin receptors as shown above.

Insulin resistant cell: If you live on a high carb diet, chances are you will have chronic high blood sugars. These chronic high blood sugars require chronic high levels of insulin, (whether it is made by our body or injected) and so these insulin receptors become resistant to the effect of the high levels of circulating insulin.

Hyperinsulinemia: If you are insulin resistant, the glucose remains high (because the insulin is not having it’s desired effect to transport glucose from the blood into the cells) the body begins to produce more insulin. Hyperinsulinemia is the elevated levels of insulin.

The Many Roles of Insulin 

Research is discovering the numerous roles insulin plays in our body, including:

  • rapid transport of glucose into cells
  • lowering of raised blood glucose
  • prevents fat burning
  • promotes fat storage
  • increases hunger
  • negative feedback with glucagon (glucose-gone) and so prevents the body from converting glycogen into glucose (NB: it now appears that processed food interferes with this signalling pathway and negative feedback, so blood sugars can be raised by processed food AND be raised by gluconeogenesis)
  • nerve communication
  • anabolic hormone
  • affects protein synthesis
  • affects hormone synthesis

Why is it so bad to be a sugar burner? Because burning sugar is a dirty fuel and causes oxidative stress, free radicals and inflammation throughout the body.

What Are The Complications Of Hyperinsulinemia?

Diagram of hyperinsulinemia and the symtpoms

Hyperinsulinemia is one of the most important discoveries in modern times. You may wish to read Catherine’s paper “Hyperinsulinemia: A unifying theory of chronic disease?” CLICK HERE.

“Hyperinsulinemia, directly and indirectly, contributes to a vast array of metabolic diseases including all inflammatory conditions, all vascular diseases, gestational and type 2 diabetes, non-alcoholic fatty liver disease, obesity and certain cancers and dementia. The mechanisms include increased production of insulin growth factor-1; reactive oxidative species and advanced glycation end-products; and triglyceride and fatty acids. Hyperinsulinemia also, directly and indirectly, affects many other hormones and cytokine mechanisms including leptin, adiponectin and estrogen.”

What Is Metabolic Syndrome?

Diagram of metabolic syndrome and its effects

Metabolic syndrome is defined as having 3 of the top 5 symptoms above. It is a cluster of conditions (termed metabolic syndrome as an umbrella term) that increases your risk of cancer, Type 2 diabetes, heart disease, stroke and dementia, just to name a few.

So for example, if you’re taking a statin, have high blood pressure, and a big tummy (dangerous visceral fat), then you have metabolic syndrome.

Glucose Tolerance Tests – Do They Tell The Full Story?


The glucose tolerance test only shows your blood glucose levels rise and fall over a few hours and does not reflect the insulin that your body produced over that period.

For example, two people may have the same glucose tolerance test results, but one may have required an excessive amount of insulin to transport the glucose out of the blood and into the cells ie: they are insulin resistance with hyperinsulinemia but still pass the glucose tolerance test.

Line charts showing hyperinsulinemia

You may have a normal glucose tolerance test for years before your blood glucose is out of the normal range BUT your levels of endogenous insulin (made in the body) could be raised for decades before.

By the time you fail your glucose tolerance test, you may already be insulin resistant, have hyperinsulinemia and probably also have metabolic syndrome.

Line chart showing timelines to developing

What Is Insulin Resistance and Hyperinsulinemia? 

Top 3 Takeaway Notes

  1. To prevent insulin resistance and hyperinsulinemia, enjoy unprocessed low-carb whole foods.
  2. Do not rely solely on the results of a glucose tolerance test.
  3. Hyperinsulinemia, directly and indirectly, contributes to a vast array of metabolic diseases.

Pinterest image showing two women having an interview and a diagram of hyperinsulinemia

Dr Catherine Crofts

Dr Catherine Crofts

Dr Catherine Crofts is undeniably the world expert on insulin.

Catherine has been a pharmacist for over 20 years as a clinical community pharmacist, hospital pharmacist and now at AUT teaching. undergraduate health science students, while continuing her research on insulin and health.

Catherine worked with Prof Grant Schofield on her Master’s thesis. A PhD followed by investigating the impact of high insulin levels on health and disease.

During this process, she discovered the work of Dr Joseph Kraft and his extensive dataset of insulin response patterns. The research showed that up to 75% of people with a normal blood glucose level, may have high insulin levels, and these high insulin levels may be a bigger risk factor for heart disease, rather than high blood glucose levels.

You can find Dr Catherine Crofts here:


If you are new here and would like to learn how to start low-carb, take a look at how to start a low-carb diet for beginners.

You’ll find all the resources you need to start a low-carb diet or how to start a keto diet.

There’s also a FAQ and simple diet sheet so you can get started straight away with some simple meal ideas.

Graphic with how to start low-carb

Get our FREE guide to finally fix your metabolism!

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Our Flip the Switch guide will help you clearly understand what’s been going on, as well as exactly what you can do to get your metabolism working again so that you can look and feel your best—it’s easier and more simple than you think!

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  1. Fantastic video thanks. I knew Catherine a few years ago when I first started on low carb (she might remember me… Lynda from the NZ lowcarb website that she was a member of as well). I did so well for so long but have strayed from the low carb path too much lately and my blood sugar is showing this. I’m back to checking my blood and trying my best to get back to low carb eating. I know it’s the only way forward for me. My last HbA1c was still in the normal range so hopefully I’ve not done too much damage yet. I was pre-diabetic back in 2011 which sparked my interest in low carb initially. Hopefully this video will be the kick up the bum I need to eat better all the time.

  2. Elizabeth Broyles says:

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    Good information.

  4. Jill Alcock says:

    You have done one of the PreKure courses I understand. I am beginning a website, Jilly’s Low Carb and put information on Instagram and Facebook. I made a nutritional food bar like the Zone 40/30/30 years ago and after reading What the Fat – got me on the path again. Your site is one of my favourites. Straight from the heart.
    Will you do any more PreKure courses and do you think they are worthwhile for someone who has substantial knowledge already?

    1. Hi there Jill, how wonderful you are starting your own blog and are getting back into nutrition again. Yes, I have completed the entire Health Coaching Course, and am now completing the full ICF coaching certification and the PK200 series. I predict I will do them all. They are the most wonderful way to upskill and keep up to date. I might see you on a coaching call with them. Prekure really is the best coaching programme in the world in my opinion. Professional. Legitimate. Super qualified. Vast speciality of experts on their faculty. And truly making a difference in health care, not sick care.

  5. Hi Libby
    My name is Juan. I am writing from Spain.Iam having a double frozen shoulder issue. I have been battling with it for 14 months now. Doctors said it is due to a bacteria. I started a keto diet I got some improve. But after 3 months I am still very low energy every single day, sleep problems , constipation and cognitive problems and cannot lose my belly fat (whcih actually increases). After watching this video all the pieces of the puzzle fit about my last 6 years health problems. Is it possible to contact privately with you in order to explain you? I am deseperate. Thank you in advance for your answer

    1. Hi Juan, I am so sorry to read about your health concerns. I am glad this article and interview on hyperinsulinemia may have answered some of your questions. Unfortunately, I do not do private consultations but I do group coaching over on Ditch The Carbs PRO. But with all health issues and health conditions, you must be under the supervision of your health care practitioner/physician.