Insulin and Triglycerides

Every time I review someone’s blood test results, and then discuss with them what they mean and what they should do to improve their numbers, there’s something I almost always have to explain. And this was the relationship between fasting insulin and triglyceride levels.

Take a look at this plot:

trigs_vs_insulin_gb

Plot showing ten pairs of measurements of insulin and triglycerides, made from the same blood samples. They were collected between 2011 and 2017, and all are from my own blood tests.

It shows measurements of insulin concentration on the horizontal axis in mili units per millilitre (mIU/ml), and triglyceride levels on the vertical axis in milligrammes per decilitre (mg/dl). This is a correlation plot in which independent measurements of one variable are plotted against independent measurements of another in an attempt to see if there is a relationship between them.

Is there an order in the way the dots are organized? They are clearly not randomly distributed as a circular cloud of dots—it would mean that there is no relationship. Instead, we see what looks like a linear relationship in which lower values of insulin correspond to lower values of triglycerides, and higher values of insulin correspond to higher values of triglycerides. It’s not a straight line, but it’s definitely a clear linear relationship, and the value of the correlation coefficient, which quantifies how tight the relationship actually is, of just under 0.9 is pretty close to 1. In other words, it’s a pretty tight linear relationship.

Triglyceride is a fancy word for fat or lipid, because fat molecules are composed of three fatty acids held together by a glycerol structure. This is what triglyceride refers to. The amount of fat in the blood is affected by the amount of fat we eat, and the amount of body fat we have. Naturally, after a fatty meal, triglyceride levels will increase as the fat goes from the digestive system into the blood, they will reach a maximum, and then start to go down. The longer we wait before we eat again, the lower they will go. But there’s a few complications.

The first is that depending on the amount of insulin, one of whose jobs it is to transport nutrients into cells, whatever is circulating in the blood—and this includes glucose, of course, but also protein and fat—will in general be stored away faster if insulin is higher, and slower if insulin is lower. This means that if you eat fat together with sugar or starch, the whole lot will be packed away, and mostly as fat, minus the little bit of glucose your muscles and liver have room to store up as glycogen.

The second is that depending on the state of insulin sensitivity—the fundamental parameter that determines how well or poorly cells can use fat for fuel—triglycerides will in general be used up faster if we are more insulin sensitive and slower if we are more insulin resistant. This means that in the morning, twelve to fourteen hours after having had the exact same meal, the more insulin sensitive person will have lower triglyceride levels than the more insulin resistant.

And in fact, no matter if we have a measure of fasting insulin or not, and no matter how little we know about the person’s overall health, fasting triglyceride concentration is probably the best general marker of insulin sensitivity. Nevertheless, because their levels fluctuate quite a lot over the course of each day as a function of what we eat and drink, it is true for triglyceride levels as it is true for many other blood tests that are affected by the kind and amount of food and drink we’ve had over the last days, and most importantly by the amount of sweet or starchy carbohydrates.

Now, take a look at this second plot:

trigs_vs_insulin_final

Plot showing, in addition to the 10 points shown in the first plot (in red), another 20 pairs of measurements of insulin and triglycerides, also all from the same blood samples, but from seven other persons.

It shows the same 10 data points shown in the first plot from my own results, but with another 20 pairs of measurements taken from other people that I’ve coached and helped with the interpretation of their results. You can see that the relationship is better defined because of the additional points that now together cover a wider range of values on both axes.

However, you can also see that, the relationship is not as tight. In particular, there are a few points that are quite far off the main trend—mostly those at the top of the plot with high triglyceride and low insulin values. We see how these off-trend points affect the tightness of the relationship seen in the initial data set when we compare the values of the correlation coefficients. These off-trend points lead us to the third complication I wanted to bring up.

But first, please take a minute to consider the matter: What could lead to having low insulin and at the same time high triglycerides? What could be the cause of the difference between my numbers, which did contain some very low insulin levels, but all of which were paired with equally low triglyceride values, and this other person’s numbers? What causes insulin to go down? What happens when insulin is low? What could cause triglycerides to go up while insulin is low?

Insulin, no matter how high it is, will start to go down when we stop eating. The longer we fast, the lower it will go. Each person’s baseline will be a little different depending mainly on their metabolic health and their body fat stores. The more efficient the metabolism is at using fat for fuel—the more insulin sensitive, the lower insulin will go. But also the lower the body fat stores are, the lower insulin will go. On the flip side, the more insulin resistant and the fatter we are, the longer it will take for insulin to drop and the higher it will stay at baseline.

This is pretty shitty. I mean, as we develop insulin resistance, average insulin levels will become higher and higher. As a result we’ll store calories into our growing fat cells more and more easily, and will therefore become fatter and fatter, faster and faster. But fat cells also secrete insulin! So, the more fat cells there are, the higher the insulin levels will be, and the harder it will be to lower our basal insulin. To burn fat, we need to lower insulin levels. The fatter we are, the higher the insulin levels will tend to be. And the fatter we are, the harder it will be to lower insulin levels.

It’s a bit of a catch, but in the end, it’s not such a big deal because basically everyone who is overweight and who starts to fast and restrict carbohydrates melts their fat stores away very well. It works incrementally: insulin goes down a little, insulin resistance is reduced a little, fat-burning starts; insulin goes down a little lower, insulin resistance is further reduced, fat-burning increases; and on it goes, until we have lost all those extra kilos of fat that we were carrying on our body, be it 5, 15, 20, 35, 60 or even 100 kg of fat! It’s just a matter of time.

Now, after this little tangent on insulin and fat stores, we can come back to those anomalous points in the plot, the most conspicuous of which is the one just below 120 mg/dl of triglycerides but only 3 mUI/ml of insulin. Have you come up with an explanation? Here it mine:

That point is from one of my wife’s blood tests. It is unusual because it was done after 24 hours of fasting. My 24-hour fasting blood test done a number of weeks before, and my numbers were 41 for trigs at 2.3 for insulin. The difference between her and I was that I was already very lean, whereas she wasn’t. Therefore, as she fasted, her insulin levels dropped very low, and then the body started releasing its fat stores into the bloodstream in high gear. This is why her triglyceride levels were this high while her insulin was that low. It’s almost certainly the same for the other two points up there with trigs at 110 and 90 with insulin around 4 and 2.5 (the latter one of which is also my wife’s).

Since we did many of our blood tests around the same time, there are 9 data points from her on the plot. Several are in the centre of the main trend at insulin values between 6 and 7, but I’d like draw your attention to her lowest insulin value that was measured at 1.8, and at which time her trigs were at 57, and her lowest triglyceride level of 48, at which time her insulin was at 2.2. This shows that on average her values are a little further along the trend than mine are because of the small difference in body fat, but that she has good insulin sensitivity, and a well-functioning metabolism that can efficiently use fat for fuel.

The other off-trend point, but in the other direction on the right hand side, with insulin just above 10 and trigs around 65, is from my mother’s first blood test which I ordered and included insulin and trigs, before I got her off carbs. She was 82 at the time, eating a regular kind of diet, but not a very nutritious or varied diet with plenty of bread and cheese, because she had serious problems moving around and taking care of herself while still living alone. And so, it’s just the result of being older, having plenty of carbs, but not being highly insulin resistant nor highly overweight. Her baseline insulin levels were just generally higher because of her age and diet, but her trigs weren’t excessively high.

However, after just four days of intermittent fasting on a very low carb regime with most calories coming coconut oil spiked green juices and coconut milk smoothies, her insulin went from 10.3 to 4.7, and she lost 5 kilos, which, of course, were mostly from the release of water that the body was retaining to counter the effects of the chronic inflammation that immediately went down with the very-low carb regime and fasting.

Later, having sustained this strict green healing protocol for about 6 weeks, her numbers were at 2.9 for insulin and 56 for trigs. And by then she had lost another 5 kg, but this was now mostly fat. She had, at that point, recovered full insulin sensitivity, had lost most of her body fat stores, and overhauled her metabolism. She was 83 at that time, which shows that this sort of resetting of the metabolism can work at any age.

On this note, let’s conclude with these take-home messages:

First, the next time you get a blood test, request that insulin and triglycerides be measured, because it’s the only way to know what your fasting insulin actually is, and because it is very telling of your level of insulin resistance or sensitivity, overall metabolic health, as well as your average rate of ageing as we’ve seen in a previous post on insulin and the genetics of longevity.

Second, when you get the results back, you will be able to tell from your triglycerides concentration, in light of your insulin level, either how well the body is using fat for fuel—in the case you are already lean, or how fast you are burning your fat stores—in the case you still have excess body fat to burn through.

And third, resetting metabolic health can be done at any time and at any age, and is yet another thing that shows us how incredible our body is—the more we learn generally or individually, the more amazing it reveals itself to be.

Want to lose weight? Here’s what you need to know in under 1000 words

One, you don’t want to lose weight: you want to lose fat. You don’t want to lose muscle or bone because they are very important functionally and metabolically. What you want to lose is fat. So weight loss needs to be reworded as fat loss.

Two, roughly speaking, the body is generally either storing surpluses or using reserves.

Three, the major fuels for the body are glucose and fatty acids.

Four, for the body to use fat reserves, insulin levels must be low. Fat cannot be efficiently utilized as long as insulin is high, because insulin promotes storage.

Five, the thyroid gland regulates metabolism and brain function. It requires adequate amounts of iodine without which it cannot work properly. To ensure healthy metabolic function, iodine supplementation is critical.

That’s what you need to know. If you want more details, I can expand a bit.

Insulin regulates fat storage

Every second that we are alive, trillions of biochemical reactions take place. The energy currency is adenosine triphosphate, ATP. Mitochondria produce ATP primarily using glucose or fatty acids. Fatty acids produces a lot more, but glucose is much easier to use. Both are used but one always dominates. In general, if there is glucose to be used, fatty acids are not much. For fat loss, we want to promote fat burning for ATP production to fuel cellular activity.

High glucose levels from carbohydrate intake trigger insulin secretion. This is necessary to bring the glucose into the cell, and to get rid of it from the bloodstream where it causes damage to the tissues by glycation. Within the cell, glucose can be either fermented without oxygen or oxidised with oxygen. Lower oxygen levels (and very high short term metabolic needs) promote fermentation. Higher oxygen levels (and lower metabolic ATP production rates) favour oxidation. More fermentation leads to greater accumulation of lactic acid, which further decreases oxygen levels. Red blood cells do not have mitochondria and therefore can only produce ATP by fermenting glucose.

Lower glucose leads to lower insulin. This triggers the release of fatty acids and glycogen into the bloodstream. If sustained, low glucose leads to the production in the liver of ketones primarily to fuel the brain whose cells can either use glucose, ketones, or medium chain fatty acids because longer molecules cannot pass the blood-brain barrier.

The higher the glucose, the higher the insulin, and the faster the uptake and storage of nutrients from the bloodstream into cells. The lower the glucose, the lower the insulin, and the faster the stored fat can be released and used.

insulinFatStorageFatRelease

Amount of glucose stored as fat and amount of fat released from fat cells as a function of insulin concentration. Plot taken from https://optimisingnutrition.com

The most metabolically active tissue is muscle. The more muscle we have, the more energy is used, and the faster both glucose and fat are burned to supply fuel to the cells. The more we use our muscles, and the more intensely we use them, the more they grow, and the more efficiently they burn both glucose and fat. Also, the stronger the muscles, the stronger and denser the bones will be. This is very important.

Therefore, as we burn more fat, we burn fat more efficiently. As we use our muscles more intensely, we burn more fat. And as we build more and stronger muscle, we burn even more fat even more efficiently, and make the bones stronger.

Different Carbohydrate Intolerance Levels

These mechanisms are universal in animals, but each animal is different, and each person is different. As far as fat loss is concerned, the individuality of people is related to their predispositions to insulin resistance and carbohydrate tolerance, (or actually, intolerance). Every person is differently intolerant to carbohydrates and differently predisposed to insulin resistance.

This is why in a group eating the same diet, there are people who are thin, people who are chubby, people who are fat, and everything in between. Basically, the greater the predisposition to insulin resistance (and the more sedentary), the lower the tolerance to carbohydrates will be, and the fatter you will tend to get. In contrast, the lower the predisposition to insulin resistance (and the more active), the higher the tolerance to carbohydrates, and the thinner you will tend to be.

This translates into different thresholds in the amount of carbohydrate we can eat without negative metabolic consequences, and consequently, the amount under which we must stay in order to burn fat instead of storing it. As a guideline, if you want to burn primarily fat for your body’s energy needs, this threshold would be around 20–25 grams per day if you are fat; around 30–50 gram per day if you are neither fat nor thin, and could be around 80–100 grams per day if you are very thin.

But no matter what your personal threshold happens to be, it will always be the case that the lower the intake of carbohydrates, the lower the glucose and insulin will be, and the more efficiently your body will burn fat as fuel.

Fat Loss Rate

The amount of fat that is burned is determined by the energy balance. The greater the total amount of energy we use, the greater the total energy needs. Total energy needs will mostly be met by energy from food intake and energy from fat reserves. If food energy intake is high, the need for stored energy will be low. If intake is lower, the need for energy from fat reserves will be higher.

Pushing this to the limit—maximal usage of fat stores—we would provide the protein necessary to maintain muscle and other active tissues and nothing more. In this situation, basically all energy needs would be supplied by stored fat reserves and glycogen when needed. This is greatly enhanced by resistance training.

The amount of protein needed is proportional to muscle mass and muscular activity. As a guideline, you can use 1–1.5 grams per kg of lean mass per day in the case of little physical activity, and 2–3 g/kg/d in the case of high muscular activity levels. Excessive protein is not great, but more is almost always better than less.

Fat burning and protein synthesis can be further optimised by intermittent fasting. Extending the time between feedings allows glucose and insulin to drop lower, which increases the rate of fat burning. And by eating fewer but larger amounts of protein in a meal is better because protein synthesis increases in proportion to the amount consumed.

Thyroid function regulates metabolism. Iodine is used in every cell, but in the thyroid, it is concentrated to more than 100 times the average of other tissues, because iodine is the main structural component of thyroid hormones. Iodine supplementation is critical because most soils are highly depleted. It is water soluble and very safe to supplement with.

Summary

  • High insulin from carbohydrate intake promotes fat storage.
  • Low insulin from restricting carbohydrates promotes fat loss.
  • Individual predispositions determine the threshold of carbohydrate tolerance.
  • Below this threshold fat is used as the main source of cellular fuel.
  • The rate of fat loss depends on balance between energy needs and energy intake.
  • Maximal fat loss rates are achieved by supplying just the protein needed to sustain lean tissues.
  • Iodine supplementation is critical to healthy thyroid, metabolic and brain function.

If you think this article could be useful to others, please Like and Share it.