And should I care? Well yes you should care. A lot. You are likely pre-diabetic… 

Who cares?

You’d care because being insulin resistance combined with a moderate to high carbohydrate diet makes you “hyperinsulinemic” – you have high insulin all the time. This means you are now metabolically dysregulated meaning your body:

  • turns fat burning off
  • promotes fat storage
  • dials down your physical activity (feel lethargic and lazy)
  • disrupts the hunger control mechanisms in the brain
  • has all the physiological factors in play (reactive oxygen species, inflammation, IGF-1 etc) which eventually result in the range of metabolic diseases which will kill most of us with a reduced quality of life for a decade before we die – diabetes, cancer, heart disease and dementia.

Understanding how your own body reacts to different types of food, stress, and other environmental factors is absolutely key to long term health, especially weight control.

That’s why we care about insulin resistance and maybe you should too… on

insulin resistantWhat is insulin?

Insulin is a protein produced by the pancreas.  It helps in the regulation of nutrients and energy around the body.  It is best known for helping move glucose (carbs) into cells so it can be used for energy.  That’s a pretty crucial function; without insulin you will die. Type 1 diabetes is a failure of the pancreas to produce insulin, so Type 1 diabetics can inject synthetic insulin.

But insulin is way more interesting than just that.  It is part of a complex hormonal and neural system that affects all parts of our body. That system controls energy storage and energy use.  That system controls:

  • Fat burning – elevated insulin turns off fat burning
  • Fat storage – elevated insulin promotes nutrients (both carbs and fat) to be stored away in fat cells
  • Physical activity – elevated insulin dials down (your brain suppresses your body) energy output
  • Hunger – a more complex interaction with insulin, leptin and ghrelin (other hunger hormones), the hypothalamus (hunger centre in the brain), inflammation and other anabolic (growth) promoting agents switch hunger off and on.  We are still learning exactly how this might work, but insulin in short spikes might switch off hunger, but when chronically high (longer term) keeps the “I’m still hungry” switch on.

What is insulin resistance?

People are said to be insulin resistant when they have trouble getting glucose into their cells.  One way to think about it is that the cells become “resistant” to insulin trying to open them up and get glucose in.  This can be temporary – for example when we starve ourselves our body wants to divert any glucose away from most cells in the body and have it used by some cells which require more glucose (eg, brain cells, red blood cells). In the meantime the rest of the body runs off fat. The same is true when we eat excessive amounts of carbohydrates. We can become temporarily insulin resistant, helping us pack away that extra energy into fat for a famine in the future.

When the body is properly regulated, the whole metabolic machine works perfectly. We produce insulin when we need to, become insulin resistant to help us when we are starving, and store extra energy when we are in times of plenty. In an evolutionary sense, this is a system designed to work across feast and famine.

Unfortunately the whole system can become “uncoupled” by modern life. Stress, lack of famine and constant feast, too little exercise, poor quality foods and much more all make you insulin resistant. Modern human life promotes insulin resistance. In fact, my colleagues at Otago University have shown that in older New Zealanders, pre-diabetes may affect as much as 50% of the populaiton.

I’d say that this condition called “pre-diabetes” really indicates the start of “end stage” failure of the body. This is because pre-diabetes is the point where people start to be unable to get glucose into their cells, regardless of how much insulin they produce OR their pancreas has started to fail because of having to produce so much insulin for so long (it’s burnt out), then we can be almost certain that the majority of the older and other higher risk groups (Maori and Pacific people in New Zealand) are insulin resistant.

We need to identify insulin resistance way before you start to fail the tests your doctor currently uses.  We’ll look at that now.

How can you tell if you are insulin resistant?

The main reason I wrote this post was because I am often asked how you tell if you are insulin resistant.  That’s a great question and hard to answer, but very very important to your health. Read on.

The health system has some serious diagnostics which will show you if you are insulin resistant. I’ve listed everything below.  You’ll know some of these already .


  • High fasting blood sugar
    • 110 to 125 mg/dL (6.1 mM to 6.9 mM) – WHO criteria
    • 100 to 125 mg/dL (5.6 mM to 6.9 mM) – ADA criteria
  • High HbA1C (glycated Haemoglobin) between 5.7 and 6.4 percent.
  • Oral glucose tolerance testing: High and prolonged levels of glucose to carbohydrates ingested (usually administered as 75g of pure glucose drink). Diagnosed with a blood sugar level of 140 to 199 mg/dL (7.8 to 11.0 mM) after two hours.

So these are the techniques your doctor will use to screen you to understand whether you have Type 2 diabetes or pre-diabetes.  All of these by definition indicate moderate to severe insulin resistance, which has probably been persistent for decades.

But it’s not the end of the story. The problem is that you can pass any one of these tests fine but still have insulin resistance and all the problems described above.

Why?  Because current medical testing looks at our inability to get glucose into cells, rather than how much insulin we are producing. Many people can move glucose into their cells at an acceptable rate but need to do so with massive amounts of insulin.

Therein lies the biggest unnoticed problem in modern medicine. We have a large part of the population told they are metabolically healthy when they are not. We send them away, tell them all is good, and it is only when they show “end stage” symptoms that we act.

Do you see a problem?

Bottom line 1: High and prolonged levels of insulin because of carbohydrates ingested, even with normal blood glucose responses, is dangerous to your health.

There is a better way – that is measuring both insulin and glucose response in the oral glucose tolerance test. That way we can see if you have this condition called “hyperinsulinemia” even with good glucose disposal.  The trouble is that would cost you nearly $1000 in New Zealand, if you could find someone willing to do it and interpret the results. It’s costly, time consuming (a few hours in a lab) and messy and painful  (lots of blood samples).

You could measure fasting insulin – but I’m not convinced that most insulin resistant people show problems here.

But can you observe symptoms yourself without a clinical diagnosis?  I think if you have a few of the symptoms below then it is likely you have insulin resistance.

A checklist

  • I’ve had trouble controlling my weight my whole life
  • I have a high waist circumference (I’ve got a fat gut) – more than 100 cm men, 85 cm women
  • I always feel hungry
  • I feel like something sweet after dinner to stop my hunger
  • Fatigue, exhaustion, depression
  • High blood pressure
  • Frequent hypoglycemia (low blood sugars)
  • You are over 50 years old

BTW – if you have failed one of the glucose tests then don’t bother with the checklist, you are already insulin resistant.

 Bottom line 2: If you have some of these symptoms, the easy “try it yourself” work around is to severely restrict the amount of carbohydrate you eat for a couple of weeks and see how you feel. I’d say if you are insulin resistant, then the carb restriction is the method which can best help you reset your metabolism.

Join the discussion 3 Comments

  • Claire says:

    My Partner and I have tried to do the Keto diet for a few months (recently lapsed) but planning to go back on it… We both lost weight, he takes pills for type 2 diabetes and when he had recent tests they say he is so much better, well on his way to perhaps being cured!
    He feels sick on his meds and thinks the diet doesn’t work with them. I would really like a recommendation of a doctor here in Auckland that would support a transition off medication using diet to heal… Does one exist?

    • What The Fat? says:

      Hi Clare,

      have a look at our LCHF practitioners resource.

      Although not every LCHF friendly doctor we know of is listed here, these doctors if busy may be able to suggest others for you.

      It’s important that your partner reduces insulin or insulin-stimulating meds, and also blood pressure meds, under medical supervision as diabetes improves – this is less important for metformin.

      • Linda says:

        Also check out I’ve been following him and his videos over a year and a half. I’ve lost 45 lbs. and depression/motivation much improved. Good luck to you!

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