It should be quiet apparent by now, that what makes you fat is excess calories as I stated in the previous blog posts, although I still have one more to write, however this painful myth about carbohydrates and insulin being fattening refuses to die, hopefully after this article, you will be fully aware of how wrong this myth is, and why carbohydrates and insulin do anything but make you fat.
So this myth seems to of come from low carbohydrate enthusiasts such as Gary Taubes and Dr.Atkins who believe insulin because it is a fat storage hormone and is raised by carbohydrate stores any carbohydrates you eat as fat, however this hypothesis has many, many fatal flaws, as you shall see.
“This alternative hypothesis of obesity constitutes three distinct propositions. First, as I’ve said, is the basic proposition that obesity is caused by a regulatory defect in fat metabolism, and so a defect in the distribution of energy rather than an imbalance of energy intake and expenditure. The second is that insulin plays a primary role in this fattening process, and the compensatory behaviours of hunger and lethargy.
The third is that carbohydrates, and particularly refined carbohydrates– and perhaps the fructose content as well, and thus perhaps the amount of sugars consumed– are the prime suspects in the chronic elevation of insulin; hence, they are the ultimate cause of common obesity.” – Gary Taubes, good calories bad calories
One major problem with this myth, is the blatant disregard for the laws of thermodynamics and that calories do indeed count and excess calories are the cause of weight-gain.
However if we disregard that part of the hypothesis for a minute, because I know some people will still be worried that carbohydrates are in some way inherently more fattening that protein or fat and that elevated insulin is extremely bad for you, even though as I shall show you, this could not be further from the truth.
I feel since I have already covered in detail the fact calories do count, I won’t dive into why carbohydrates are not fattening, because as you have seen, no macronutrient is fattening unless eaten in excess and as I discuss in my blog posts on white rice and potatoes, these carbohydrate based foods are great for the amazing fat-loss properties they have. What I want to do in this blog post, is break the ridiculous idea that insulin is fattening and that we should all avoid foods that create an insulin spike.
During this article I will do my best to destroy this myth once and explain how unfair it is blame all the obesity epidemic on such a vital hormone and why if it were not for this hormone, it would be extremely hard to look good, burn fat and build muscle.
You see, insulin is indeed a storage hormone, this means one of its purposes is to help us store the food we eat in our cells, but this is by far from all it does.
The first major problem with avoiding foods that create a large insulin spike, is carbohydrates are not the only food which create a substantial insulin spike, many protein based foods also create a substantial insulin spike.
In a study comparing 240 calories worth of many different types of foods to see what level of insulin response they would give, fish actually gave a higher insulin response than white pasta and beef a higher insulin response than porridge. Also very interesting, the food which gave the highest insulin spike, in a similar styled experiment, but focusing on satiety of foods, the potato also has the highest in a satiety of any food. (1,2)

In another study comparing 4 different types of protein meals, all in liquid format from tuna, whey, egg and turkey to assess the different insulin spikes because high insulin producing foods could help promote higher levels of fullness for longer.
Because although in the world of fitness guru’s insulin makes you fat and this study doesn’t make any sense, obesity researchers know otherwise and make no bones about it, this is the opening extract from the study itself:
“Insulin is thought to be a satiety hormone, with increased insulin levels in the brain eliciting a net catabolic response influencing food intake regulatory mechanisms. Dietary proteins have been shown to stimulate insulin release and influence glycaemia differentially”(3)
So what were the results, well for people who enjoy whey protein, you’ll be glad to know it gave a huge insulin spike and was by far the highest out of all four protein shakes. The glucose response was also much lower with the whey protein that the egg or turkey, but not significantly lower than the fish, this is very important and i’ll get onto it later.

The subjects were all significantly fuller on the whey and tuna shakes than the egg or turkey and four hours later after each different shake the participants were allowed to eat as much food as they wanted until comfortably full from a buffet, not surprisingly, the whey shake left people with the lowest appetite as they ate the least from the buffets, with tuna next, then turkey, then egg, perfectly correlating with insulin release.
As you can see, foods high in protein can give just as much of a insulin spike as foods high in carbohydrate, yet we all know a tuna steak doesn’t make you fat right!
The reason foods high in protein raise insulin is because the branched chain amino acids can directly stimulate the pancreas to produce insulin, with leucine having the strongest effect and if you haven’t guessed yet, whey protein is of course extremely high in leucine. This is one of the reasons essential amino acids can be so effective, they give a large insulin spike and all the amino acids are then pushed directly into the muscle for all that muscle building goodness. (4)
If you have a strong belief about insulin making you fat, I’m sure you are currently having a bit of a breakdown, I know I did when I first learnt this information, but stay with me. As you can see, if insulin makes you fat, then its not just carbohydrates that are a problem, but also most proteins and the ones high in brained chain amino acids that are great for building muscle raising insulin the most.
In another study looking at the best macronutrient ratio to increase leptin levels, which is you don’t know much about leptin, is a anti-obesity hormone strongly linked to body-fat and hunger levels, with higher levels decreasing hunger and making it easier to lose weight, especially if the person has good brain leptin sensitivity, only the meal that raised insulin levels high also raised leptin levels, meaning keeping insulin low, is likely to decrease leptin levels and increase long-term hunger a long with body-fat levels. (8)
Okay, so now that your belief about insulin being fattening being on shaky ground and not the root of all evil, let me explain why insulin is actually keeping you thin, but first i’m going to explain to you how diabetes type 1 actually works and what insulin does.

So most people think diabetes type 1 is really bad because the lack of insulin production stops glucose getting into muscle and fat cells and is instead left floating around in the blood stream causing havoc, but thats far from the truth and unfortunately based mainly on current dogma, instead of fact.
You see we don’t need insulin to store the carbohydrates we eat, when type one diabetics are measured for glucose uptake during severe hyperglycaemia, glucose uptake is increased above normal in the absence of insulin. This is because we have glucose transport proteins of which as least 6 isomers are known, these are glut 1-6. These transports can move glucose directly into fat and muscle cells in the absence of glucose and this is exactly what happens with type one diabetics. (5)
This is where all your bad words about insulin need to be rapidly retracted, because you are about to find out that without regular releases of this amazing hormone, you would be very hungry, fat and ageing very quickly.
Because the major role of insulin is not to store carbohydrates as fat, but actually to turn off excess liver production of glucose and ketones. You see, when type one diabetics don’t have high blood sugar because they can’t store the glucose eaten, they have high blood sugar because the liver over produces glucose and ketones until it is told to stop and insulin is what tells it to stop.
If it wasn’t for a big insulin spike when you eat, you would continuously get high blood sugar problems, not because you were not storing the carbohydrates you eat, but because insulin stops the liver over producing more glucose to be used, insulin tells the liver to stop this.
Remember earlier when I mentioned that whey protein had lower glucose response than all the other proteins, which would mean more stable blood sugar, this is because the high insulin spike from whey decreases the amount of glucose production from the liver, where as the proteins that spike insulin less didn’t do this as effectively, this means more glucose is produced by the liver creating less stable blood sugar.
So contrary to popular belief, a large insulin spike helps keep blood sugar levels low and stops wild blood sugar fluctuations which are created by the livers over production of glucose because when insulin is not around, the liver over produces glucose as is seen in type one diabetics.
So far we’ve seen that protein rapidly increases insulin production, especially if the protein is high in branched chain amino acids, the higher the insulin release the fuller we feel after that meal, without insulin the liver over produces ketones and glucose causing blood sugar problems and if untreated would eventually lead to death, but thats not all, insulin also has some other tricks up its sleeve and these are that when insulin is released, it stimulates the release of another appetite suppressing hormone, which slows gastric empting and digestion.
And that hormone is Amylin, very simpley, amylin works by increasing the time it takes for food to empty from the stomach, this increases satiety, improves digestion, it also increases the release of a glucagon-like peptite-1, which itself helps decrease appetite and food intake. (6,7)
Conclusion
By now I think it should be clear that the idea insulin causes weight-gain is not only completely insane, but also totally unsupported by science, insulin is a vital hormone in the body, which does a lot more than push carbohydrates into fat cells and if it did do that, then the only way to lose weight would be by eating a diet low in carbohydrate, low in protein and extremely high in fat, but I can’t see that happening. Without adequate insulin it would be a real struggle to build muscle, and feel full, since insulin is strongly correlated with feelings of fullness and satiety.
If you are wondering what this means, its simple, stop worry about insulin making you fat and trying to control it, focus on eating foods that create long-term feelings of fullness and not overconsuming calories, eating carbohydrates such as potatos, white rice, sweet-potato’s and fruit can and should be part of this, forget about insulin and carbohydrates making you fat!
If you found this article helpful, please feel free to share it on facebook and twitter, it would be much appreciated, as a lot of people need to know the truth.
P.S This is just a review, if you want more information on why insulin is not the fat-loss villain you think it is, keep your eyes pealed as the full chapter on this will be out in my book soon.