Lets quickly talk about insulin resistance.
WHAT IS Insulin Resistance?
To get an idea of what insulin does, check this out – insulin the basics. With this understanding it is easier to grasp what insulin resistance is and also get closer to understanding about metabolic dysfunction and metabolic flexibility. Insulin has a central role in energy substrate partitioning. How well we can burn our fat stores, how easily we can switch between burning carbs and fat. Resilience lies in this flexibility. Insulin resistance is complex and the science is always progressing as new information is discovered.
It is important to understand the concept because this idea is tied up, as a causative factor in chronic illness that is restricting our ability to live long, medication free, enjoyable lives.
First off we can be transiently ‘insulin resistant’, which in certain situations is thought to be beneficial to us – for example in critical illness. This ‘physiological’ insulin resistance which can also be noted in some on a very low carb diet, is thought to exist to free up glucose for use by tissues that can’t use any other energy substrate e.g ketones or fatty acids. We could call this ‘glucose sparing’ to prevent confusion. Is prolonged physiological insulin resistance good for us? – that’s a great question that I don’t have the answer to.
When a person is chronically ‘insulin resistant’, insulin persistently doesn’t have the designed effect on the tissues it is destined to impact.
For example, an insulin resistant fat cell is the end result of too much energy substrate (glucose/fatty acids) than our system needs. Too much glucose, too much fat that we don’t require for what we are doing with our bodies. An insulin resistant brain cell is increasingly thought to be a factor in dementia.
A fat cell (adipocyte) that is too full, already stuffed, bulging with stored energy becomes resistant to insulin, it literally can’t let anymore energy substrate in, there’s just no room. So it refuses insulin’s actions. The insulin whose job here is to knock on the door and get the fat into the cell, fails at its task = insulin resistance.
This happens at our ‘personal fat threshold’. A threshold that’s different in different people and different ethnicities. Once we meet that threshold, the pathological effects of having too much energy rolling around begin. This is where the idea of the ‘TOFI'” individual comes from, as much as I dislike the term – ‘Thin on the outside, fat on the inside’.
Agitated and angry, the fat cell spews out some of its contents into the blood stream – the triglycerides it stores. This inflamed, angry fat tissue causes all sorts of immune responses, cytokines cascade and white cells march to the area, but the cause of the inflammation cannot be fixed by these responses, the inflammation becomes chronic, resulting in the pro – inflammatory environment associated with many chronic diseases.
The pancreas makes more insulin to try and shove the fat into the fat cell and keep it there, this high baseline of insulin is hyperinsulinaemia. This maybe where the affects of physiological insulin resistance and pathological (disease causing) insulin resistance seperate themselves.
When we run out of room in our fat cells we start to store fat in places there should be no fat – around the organs in our abdomen (this is why waist circumference is a helpful tool), in our organs – Non alcoholic Fatty liver disease, around our heart, not good.
Even if we haven’t eaten anything, if there is more glucose and fat in our diet than our body needs, the effort of keeping the fat in the cells requires a high base line of insulin.
Eventually this situation can result in disease states such as type 2 Diabetes. In type 2 diabetes we’ve reached our personal fat threshold, the insulin we make is it isn’t very effective anymore, the fat tissues just don’t respond to it and we make more and more insulin to try an counteract this. So now in our blood stream we’ve got excess sugar that can’t get into the cells and excess fat thats leaking out of them, causing inflammation AND lots of insulin – bad news. Energy substrates aren’t meant to be hanging around in our blood stream.
Insulin resistance and hyperinsulinamia are now understood to be a baseline, important mechanistic causes of many chronic diseases and health issues – type 2 diabetes, dementia, cancer, heart disease, strokes, erectile dysfunction, mood disorders, gut disorders, the list goes on.
Different cells can have different amounts of insulin resistance. Your muscles can be more or less insulin resistant than your liver or your kidney – all can have different results in tests that we do, but all are caused but the same thing resulting in different problems.
Your insulin resistance is directly related to the SIZE of your adipocytes (fat cells). The fatter and more chock full your adipocytes are – the more insulin resistant you will get.
A subset of people can make more fat cells. Little tiny fat cells ready to accept all the excess energy that we don’t use. These people can become incredibly overweight without evidence of metabolic dysfunction, that is without the excess triglycerides and glucose stuck in the blood stream, without the ectopic fat stores around the organs or in the liver. These people are NOT most people.
Those of us that don’t make more fat cells try and jam the fat in the cells we already have and exhibit the signs of metabolic dysfunction or metabolic syndrome. 1 in 4 of the adult UK population is thought to qualify as having metabolic syndrome resulting in significantly increased risks of things we are scared of – cancer, heart disease, stroke, and numerous other illnesses that we seem less scared of but that are just as significant and life shortening.
The Personal Fat Threshold is different for us all. Signs of metabolic syndrome means we are at it!
The fast road to reaching your personal fat threshold is eating a combination of ultraprocessed carbs and processed fat – refined vegetable oils.
These types of hyperpalatable foods are designed to make it hard to stop eating. They activate dopamine receptors making us feel good, they cause swings in blood sugars resulting in lots of hunger and they switch off satiety centres so we just don’t feel full. The result is excess energy that we don’t need and have to find storage for, with very little nutrient density.
‘Keeping intake to levels that support exercise but not body fat’ as Crossfit HQ supports is incredibly difficult on a highly processed diet that’s full of both ultrarefined carbs and refined fats, it has very little to do with will power. If we want to stave off chronic illness and keep active until our 90’s, these ideas are central to our success.
For some insight into my thoughts on optimum nutrition check this. https://resiliencehealth.co.uk/2020/01/25/optimum-nutrition/
Alberti KG, Zimmet P, Shaw J; IDF
Epidemiology Task Force Consensus Group. The metabolic syndrome a new worldwide definition. Lancet