Leah:

Hello and welcome to the Ideal Nutrition Podcast. I am Leah Higl and I’m here with my co-host Aidan Muir and today’s episode will be all about reversing insulin resistance. So we will be defining obviously what insulin resistance is, how it’s and what can actually be done to potentially reverse insulin resistance or improve it. Since this is a broad topic, we are not gonna cover absolutely everything.

For example, it could be caused by things like certain medications, but if we go down that rabbit hole, we are opening up several rabbit holes that would just take a lot of time to go through. So we’re going to address the things that make the most sense and are nutrition focused.

Aidan:

So starting with the definition of insulin resistance, as the name suggests, it’s when the body is resistant or less sensitive to insulin. Among other things, insulin takes glucose out of the blood to be stored or utilised. Being resistant to that can lead to issues. For example, it is a key factor in diabetes development. So that’s why we’re talking about this.

Leah:

So how do we actually go about measuring it? It is actually very rare to directly measure insulin resistance itself. So we often measure things like fasting blood glucose levels, fasting insulin, HbA1c, as well as oral glucose tolerance tests. So none of these things directly measure insulin resistance, but they can obviously indicate the presence or lack of insulin resistance overall.

In research, insulin tolerance tests involving injections are sometimes used to measure how quickly glucose is cleared from the blood. The other option is big word incoming, hyperinsulinemic euglycemic clamps. This is complex, which is why it’s mainly used in research and not practically on a person to person basis, but it is the gold standard for measuring specifically insulin resistance.

It involves infusing insulin to maintain steady blood insulin levels while glucose is also administered to maintain blood sugar levels and the amount of glucose required indicates the body’s sensitivity to insulin overall. But again, this isn’t something that is used in a person to person practice.

Aidan:

In terms of what causes insulin resistance, there are two main causes identified very clearly. So one of them is a lack of physical activity and the other one is higher levels of body fat, particularly abdominal body fat. Those are the two main controllable ones in a way, but there are a lot of things outside of our control. For example, age and genetics. Typically as people age, insulin resistance increases over time. And there are a variety of other factors such as like stress, lack of sleep, et cetera. There are deeper mechanisms proposed that are potentially linked to things like inflammation, but the stuff that I’ve just mentioned there are like very clearly linked, whereas there’s a long list of things that may or may not be factors.

Leah:

In terms of what can be done to ideally reduce insulin resistance and improve these things. So starting off with exercise. Exercise can help through a variety of different mechanisms. So one is simply that it can improve body composition and both having more muscle mass and less body fat can improve insulin sensitivity. Another reason is that exercise also reduces blood glucose levels directly as the glucose used in the blood is used as an energy source during exercise. And then plus lower circulating levels of insulin could potentially help as well.

Other proposed mechanisms include things like improved mitochondrial function, increased activity of insulin receptors as well as reduced overall inflammation and improving other factors of like metabolic syndrome that are also linked with insulin resistance. So it can definitely help in many ways and is something that would be recommended as an like part of an overall approach.

Aidan:

Reducing body fat also helps with insulin sensitivity. It’s one of the clearest factors too. Similarly to the exercise stuff where you just had Leah like list a bunch of things, it’s so multifactorial in terms of how it can help. I wish it was one of those things that was like very simple being like, this does this because of X, Y, Z reason. But going through some of the reasons, reducing visceral fat helps with insulin receptor function and also reduces inflammatory cytokines that can interfere with insulin. It can help with better liver function because when fat builds up in the liver, it interferes with the liver’s ability to regulate glucose. And there’s also reduction free fatty acids that are linked with insulin resistance. Turns into a massive list, but in general, just reducing body fat typically helps with this.

This is also why we see in, if we look at the diabetes research, in a lot of cases where there is large weight losses in people who had a lot of weight to lose to the baseline, we see huge improvements in diabetes. For example, we’ve previously spoken on the podcast about like some of the research looking at very low calorie diets in terms of, there’s many downsides to doing those, right? But like if somebody happened to succeed with that and lose a large amount of weight through that, we see

pretty clear improvements in insulin sensitivity and also blood glucose level management. When people undergo bariatric surgery, we see these things. I’ve used those things as examples because they’re so clear cut and so measurable. But if somebody got leaner and they did it in a slower slash what you could call a more sustainable way or whatever, the same concept still applies as well.

Leah:

Yep. So the next topic is covering individual nutrients. So obviously we’ve covered exercise, covered fat loss. Dietary quality overall is something that could be beneficial to look at. So we’re going to keep this brief as this section again, couldn’t kind of blow out if we’re like looking at all the research individually and going through one by one to a great extent, but just listing some of the nutrients that have evidence for helping insulin resistance, particularly in contexts where they’re addressing a suboptimal intake include things like magnesium, omega-3, chromium, vitamin D, polyphenols and zinc. There are quite a few others, but those are the main ones. You can view this from a few angles. I think the first one that makes the most sense is that it makes sense to have a nutrient rich diet. So obviously the other things we’ve spoken about are high up on the list of priorities, but having a good quality diet full of a range of different plant-based foods and making sure you are having an adequate amount of these micronutrients is important. And this is actually a factor why certain high quality dietary approaches are linked with less insulin resistance, even when calories are similar.

The other angle you can see this from is that it could be more targeted. So for example, if someone happened to have insulin resistance and covered most of their bases through just having a good quality diet, they could supplement like one to two things individually that are relevant to them and that could further improve things. Alternatively, if you weren’t going to cover most of your bases, ideally you do, because there are things that we can’t really get through supplements, but it’s a case of maybe adding a broader supplement like a multivitamin to your approach. This stuff does not help as much as the fat loss and exercise components, but it is still relevant.

Aidan:

I’m at a tiny crossroads in terms of how I communicate nutrition information in terms of the example I’m going to use here is vitamin D and helping with insulin sensitivity or reducing insulin resistance. I think as a broad claim, I’m like, it does do that particularly when used in the right context. There recently, I swear I just over the last few years, there’s been a few people mostly UK based, which there’s a difference in the UK in that vitamin D is far more broadly recommended at a population level, even in government guidelines, particularly over winter. But there’s been a little bit of a pushback against vitamin D mattering. And I partly look at that through the lens of people finding research showing that it just doesn’t make that much of a difference and kind of looking from that angle. And I want to give my two cents on this topic.

One thing is if you got me a bunch of people who were deficient in vitamin D, let’s say fully deficient, not just like insufficient intake, but fully deficient, and you address that with supplementation or sunlight, I think you’d be very likely to see a statistically significant increase in insulin sensitivity. I think that’s pretty clear cut. It becomes more debatable the closer you get to good or great levels of vitamin D.

The next angle that I really wanted to talk about though, specifically on that topic is how much did you slash they think that one individual is going to matter, that one individual nutrient. There is so many things going on. We see this in other areas. Like if we look at Omega-3s, we look at all these things. Like I’m going to use Omega-3s for example, if we look at cardiovascular disease, like did we, did we really think that adding a couple of grams of Omega-3 was going to massively reduce somebody’s risk of cardiovascular disease? When it’s so multifactorial with so many things going on.

And when you look at it from that angle with vitamin D and insulin sensitivity, like it makes sense to address, as well. Did we really think that was gonna move the needle? Just as like you said earlier, like this stuff doesn’t help as much as exercise and fat loss, it’s still relevant. And it makes sense to tick as many of these boxes as you can. And that’s one of the many, many, many, many boxes you wanna tick. That’s how I talk about it. And the only reason I’m bringing that up specifically is because some people would take the other side of the argument and be like, but I found XYZ studies showing that made no difference. And it’s probably just because it’s making a small difference in specific circumstances where it is relevant.

And that’s where I talk about the crossroads of, think if you think that if you go too deep down that route, you start coming to the conclusion that almost nothing matters. There’s very few things that really matter and really move the needle. And like I do this for a profession. I’m trying to like help people as much as can. And you look at all these little easy wins and it makes sense to implement a lot of these easy wins as well.

Leah:

Yeah, and it’s not even just the direct impact of these individual nutrients. Like you could look at it from the idea of when you have a high quality diet and you don’t have deficiencies, you’re probably more likely to exercise more frequently and do things that align with fat loss and maintaining a calorie deficit. like it also can feed into the things that are really more relevant as well.

Aidan:

100% particularly when you take that broad approach as well. So it’s funny that I’ve gone from talking about the everything kind of mattering. So I’m going to go a little bit to that one. This section with this one, I’m going to be talking about timing of eating. So it is funny that I take the opposite perspective on here, but it’s true that our insulin sensitivity is higher at certain points of the day. You’ll hear people talk about this when they talk about that whole, eat breakfast like a king and dinner like a pauper or whatever. This is also relevant for night shift workers as well, where insulin sensitivity is typically messed up a little bit overnight as well. So there is some relevance to it.

My thoughts is that you probably shouldn’t focus on this just because I really think that any change you make in relation to this is probably going to have a bigger impact on the other stuff that will affect insulin sensitivity than the actual change itself. And it’s hard for me to kind of explain what I mean by that, but let’s use an actual example. Say you’re a night shift worker and you hear somebody say what I just said and you’re like, okay, well if insulin sensitivity is lower overnight, I’m just not gonna eat overnight.

The odds that you’ll inadvertently reduce your calorie intake by doing that action is incredibly high. And reducing your calorie intake and or getting leaner improves your insulin sensitivity. And that would likely outweigh that decision about whether you eat or not overnight. That’s my own two cents, but I think the main move is how do you set it up so that you exercise consistently? How do you set it up so you eat an appropriate amount of calories and have a good micronutrient intake and a good diet overall?

And then you let that fall wherever it falls. Maybe that doesn’t mean you pay no attention whatsoever to the timing of your eating, like I still think you should pay attention. I just wouldn’t have that be the number one priority above everything else. I would just have it be one of the small factors where the other stuff is a bigger focus.

Leah:

From a lifestyle perspective, overall, it’s probably worth mentioning things like stress and sleep because they do play a role in insulin sensitivity. So having high levels of stress and poor sleep do contribute to insulin resistance. So it’s worth managing these things on top of the other things we’ve spoken about. it won’t, sorry. It will directly improve insulin sensitivity. And secondary to that, will likely indirectly improve those other behaviours we spoke about. If you’re not very stressed, if you’re getting really good sleep, again, more likely to exercise, more likely to manage your calorie intake, more likely to manage your dietary quality. So when these things are managed well, it can have both that direct and indirect impact on insulin resistance and sensitivity.

Aidan:

So as a bit of a summary, although insulin resistance is rarely measured, there are many cases where it is likely relevant and can be identified indirectly through all of those means we kind of talked about earlier. Also as a bit of a side note, it is interesting that there’s a lot of people who say, I am insulin resistant without it ever have been measured as well. Even I went somewhere and saw somebody like be diagnosed with insulin resistance without any of those testing being done. Like somebody just saw somebody like struggled to gain muscle. They’re like, I think it’s because you’re insulin resistant. That’s it.

Leah:

Not exactly a diagnosis.

Aidan:

And basically what we of spoke about is actually complex to measure it directly, but it is something that you can indirectly find out through a few more sophisticated means than just that one. But in every case I’ve seen, there are many things that can be done. Even if genetics is playing a role and age is playing a role, nobody has perfect nutrition and training and sleep and stress management. I’m yet to meet someone. So I’m always like, there are things you can do. It’s not one of those things that you would want to talk up and be like, I’m just genetically like this because that can be a huge factor. But the other stuff is always a factor as well. In many cases, there’s room for large improvements as well. And that can translate to big improvements in long-term health.

Leah:

This has been episode 182 of the Ideal Nutrition Podcast. If you haven’t yet left a rating or review, it’s always greatly appreciated for you to do so, but otherwise, thanks for tuning in.