Key Topic

In today’s episode, we’re diving into the topic of reversing insulin resistance. We’ll start by defining what insulin resistance is, how it’s measured, and explore practical strategies to address it. While it’s a broad subject with many contributing factors—like certain medications. We will focus on the most relevant aspects and avoid going down less applicable rabbit holes.

What Is Insulin Resistance

  • As the name suggests, it is when the body is resistant, or less sensitive, to insulin.
  • Among other things, insulin normally takes glucose out of the blood to be stored or utilised.
  • Being resistant to this can lead to issues. For example, it can be a key factor in diabetes.

How Do We Measure It?

  • It’s actually very rare to directly measure insulin resistance. 
  • We often measure things like:

–  Fasting BGLS

– Fasting insulin

– HbA1c

– & Oral glucose tolerance tests

  • None of these directly measure insulin resistance. But they can be obviously indicate the presence or lack of insulin resistance 
  • In research insulin tolerance tests involving injections are sometimes used to measure how quickly glucose is cleared from the blood.
  • The other option is hyperinsulinemic-euglycaemic clamps. This is complex, which is why it’s mainly used in research, but it is the gold standard.
  • It involves:

–  Infusing insulin to maintain steady blood insulin levels while glucose is ALSO administered to maintain blood sugar levels. 

– & The amount of glucose required indicates the body’s sensitivity to insulin overall

What Causes Insulin Resistance?

  • This will partly give away some things that we will talk through. But the two main causes identified are lack of physical activity and higher levels of body fat, particularly abdominal body fat. 
  • There are other things outside of our control such as age and genetics.
  • And then there are a variety of other factors such as stress and lack of sleep.
  • There are deeper mechanisms proposed potentially linked to things like inflammation, but the stuff we have mentioned are the things that are clearly linked.

Exercise

  • Exercise helps through a variety of mechanisms
  • One is simply that it improves body composition. Both having more muscle and less fat improve insulin sensitivity.
  • Exercise also reduces blood glucose levels directly as the glucose is used as an energy source during exercise. + Lower circulating levels of insulin could potentially help.
  • Other proposed mechanisms include:

– Improved mitochondrial function

– Increased activity of insulin receptors

– Reduced overall inflammation

– & Improving other factors of metabolic syndrome that are also linked with insulin resistance 

Fat Loss

  • Reducing body fat will reduce insulin sensitivity. It is one of the clearest factors.
  • Once again it is multifactorial how it helps:

– Reducing visceral fat helps with insulin receptor function and also reduces inflammatory cytokines that interfere with insulin

– Better liver function. When fat builds up in the liver, it interferes with the liver’s ability to regulate glucose.

– There is a reduction in free fatty acids that are linked with insulin resistance 

– It could be a long list beyond that. 

Individual Nutrients

  • The next topic is individual nutrients.
  • I’m going to keep this brief as this section could blow out if we looked at all of the research individually.
  • So just listing some nutrients that have evidence for helping with insulin resistance if they are addressing a sub-optimal intake, these include:

– Magnesium

– Omega 3

– Chromium

– Vitamin D

– Polyphenols

– Zinc 

And a bunch of other things too, but those are the main ones.

  • You can view this from a few angles.
  • The first one is that it makes sense to eat a nutrient rich diet. 
  • This is actually a factor in why certain high quality dietary approaches are linked with less insulin resistance even when calories are similar
  • The other angle is that we could be more targeted.
    • For example: If somebody happened to have insulin resistance and covered most of their bases, they could supplement 1-2 things individually that are relevant to them 
  • Alternatively, if they WEREN’T going to cover most of their bases, it’s a case for adding in a broader supplement like a multivitamin. 
  • This stuff doesn’t help as much as exercise and fat loss but it is still relevant.

Timing of Eating

  • It’s true that our insulin sensitivity is higher at certain points of the day.
  • This is an argument some people make for having carbs earlier in the day vs later.
  • It’s also relevant for shift workers where insulin sensitivity might be worse overnight.
  • My genuine perspective is that I wouldn’t focus on this. With the goal of improving insulin sensitivity, I’d be focusing on all the other stuff. 
  • This timing is arguably more relevant for managing blood glucose levels in the shorter term. But even in that case I’d be focusing on more of the big picture stuff.

Sleep + Stress Management

  • We won’t talk about this much since it isn’t directly nutrition-related, but both stress and sleep play a role
  • Having high levels of stress and poor sleep contribute to insulin resistance
  • It’s worth managing those for two reasons:

1) It will directly improve insulin sensitivity.

2) It will likely indirectly improve other behaviours that improve insulin sensitivity.

Summary

Although insulin resistance is rarely measured directly, it is often relevant and can be identified indirectly through various signs and symptoms. In every case we have encountered, there are always steps that can be taken to improve the situation. Even when genetics play a role, factors like nutrition, training, sleep, and stress management are rarely optimised. By making meaningful changes in these areas, there is often significant potential for improvement, leading to better long-term health outcomes.