“Insulin Resistance (IR) is most likely the single most important factor in our health.” Dr Peter Brukner

If you are insulin resistant, you are at risk of becoming obese (if you’re not already), and developing a range of diseases, including metabolic syndrome, high blood pressure, type 2 diabetes, cardiovascular disease, cancer, neurological disease, and for women, polycystic ovary syndrome (PCOS).

Insulin is a hormone secreted by the pancreas, which sits in the abdomen. When we eat a carbohydrate food, the carbohydrate is broken down in to glucose in the gut and absorbed into the bloodstream. That’s when insulin get’s to work. It’s role is varied, but one of it’s main roles is to move the glucose out of the blood and in to tissues, especially the brain and the muscles where it can be stored as glycogen (the body’s storage form for carbs) for later use as a fuel. Once the storage capacity for glycogen in the liver and muscles is complete, insulin takes the excess glucose to the liver, where it is converted into fat. That fat will only be mobilised for fuel when insulin levels drop.

In a normal system, insulin and glucose levels drop after the glucose from a meal has been absorbed into the tissues, the body responds by feeling hungry and the brain tells us to eat again. This is why we feel much hungrier a few hours after a carbohydrate-dominated meal, especially one with a big sugar load, than after a meal of protein and fats.

When the diet is consistently high in carbohydrates, in the form of sugar or other carbs such as starches or grains, the level of insulin in the blood remains elevated. This both:

  1. leads to storage of the excess carbohydrate as fat, and
  2. prevents the breakdown of fat when we need fuel.

A third effect of long term high blood insulin levels is that after a time, the body’s tissues become resistant to its effects. Just as an alcoholics body becomes tolerate to alcohol, so too do our bodies become tolerant to insulin.

It was traditionally thought that obesity was the main cause of type 2 diabetes, and there’s certainly as association between the two, but the modern thinking is that insulin resistance is the cause of both obesity and type 2 diabetes.

The main cause of insulin resistance is a diet full of sugar and highly processed foods (including vegetables/seed oils). The high glucose load from these foods leads to high insulin levels (hyperinsulinemia), eventually leading to insulin resistance. Other factors lead to insulin resistance including poor sleep, and lack of physical exercise.

Adapted from Dr Peter Brukners Book, A Fat Lot of Good.

I recently did an interview with Dr Ben Bikman on my podcast. I highly recommend you listen to this, as I learnt new things about insulin and insulin resistance.

Or watch it here here:

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