The Real Cause of Insulin Resistance?

Insulin Resistance has become a common condition, a high carbohydrate diet was often explained as the cause of insulin resistance and that you should, therefore, follow a low-carb diet. Often, however, eliminating carbs does not get to the root cause of insulin resistance. However, research is now suggesting that there may be another cause for insulin resistance.


What is Insulin Resistance


What is Insulin?


Insulin is a hormone made in the pancreas and it has many roles in the body. However, one critical role is to keep blood sugar levels under control.


When we eat a meal high in carbohydrates, the starch is broken down into glucose, it is then shuttled to the muscles as fuel.

However, this is where insulin comes into play. Insulin is a like a key opening the door allowing blood sugar to enter muscle cells.

With insulin resistance, unlike Type 1 Diabetes, there is insulin in the body, but it does not work properly.


What Causes Insulin Resistance?


In a video (click here to view), created by Dr Greger from Nutrition Facts Org, Dr Greger discusses how in a study dating back to the 1930's aimed to look at the effects different diets have on insulin.


The study examined two groups. Healthy young men were split into two groups. Half of the participants were put on a fat-rich diet, and the other half were put on a carb-rich diet. The high-fat group ate olive oil, butter, mayonnaise, and cream. The high-carb group ate pastries, sugar, candy, bread, baked potatoes, syrup, rice, and oatmeal.


The results of the study identified that within two days, tests showed that the glucose intolerance had drastically increased in the group eating the high-fat diet. This group had twice the blood sugar levels than the high-carb group. The results, therefore, suggested that a high-fat diet, in turn, results in high blood sugar levels.


Fat and Insulin Resistance?

It is only decades later after, undertaking an MRI, were researchers able to finally able to identify why this was the case.

The cause of insulin not working properly is because of intramyocellular lipids, the fat inside our muscle cells.


Scientists used MRI techniques to identify what was happening inside people’s muscles as fat was infused into their bloodstreams. The scans indicated that elevated levels of fat in the blood was interfering with delivery of glucose into muscles in turn resulting in insulin resistance.


It is suggested that fat in the bloodstream can build up inside the muscle cell and create toxic fatty breakdown products and free radicals that can block the insulin signaling process. Once process by which insulin is blocked, no matter if you have insulin, if it is unable to unlock the door to the muscle cells, blood sugar levels will continue to rise in the blood.


It is further suggested that glucose interference, causing insulin resistance, can occur within just 3 hours of eating fat. While lowering the level of fat in people blood on the other hand, can also help in decreasing the amount of sugar in the blood and in turn reducing insulin resistance.


How To Manage Insulin Resistance


Many have suggested that following a high fat low carb diet simply managed their blood sugar levels. For many who follow a Ketogenic Diet and struggle to lower the insulin resistance, this is because insulin does not work well on a high fat diet. Simply lower the fat intake and see a reduction in insulin resistance.


Reduce Fat Intake

Data from an experiment found that reducing fat consumption from an average of 54 grams per day to an average of 27 grams per day allows your insulin to function properly again and in turn increasing insulin sensitivity.


Type of Fat

Studies have shown that it is also about the type of fat that you consume that can help insulin resistance. Consuming long- and short-chain omega(3) fatty acids can significantly improve it.




Greger, M. (2017). What Causes Insulin Resistance? Nutrition Facts Org. 33. Available from:

Rivellese AA, De Natale C, Lilli S. (2002). Type of dietary fat and insulin resistance. Annals of the New York Academy of Sciences. 329-35. Available from:

Riccardi G, Giacco R, Rivellese AA. (2004). Dietary fat, insulin sensitivity and the metabolic syndrome. Clinical Nutrition. 447-56. Available from:




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