There are several hormones that, when operating properly, will optimize metabolic function.

We’ll start with the more familiar, insulin. The job of insulin is to simply transport glucose (carbohydrates) out of the bloodstream and into either the liver, muscles, or fat.

Your liver is able to store approximately 100 g of glucose in the form of glycogen. The muscles can store between 325-375 g of glycogen on average. And you can safely have 25 g or so circulating in your bloodstream.

So what happens when the amount of glucose coming into your body exceeds the available storage space in the muscles and liver? It gets converted and stored as fat.

However, as I’ve preached for almost two decades—carbs are not the enemy. Crappy carbs in high doses are.

Much of our obesity epidemic directly correlates with the overconsumption of refined carbohydrates and sugars which leads to insulin resistance, which leads to obesity and Type-II diabetes.

To demonstrate just how powerful insulin resistance can be. Researchers conducted an experiment in which subjects were gradually administered upwards of 100 units of insulin per day over a six month period. Despite consuming an average of 300 fewer calories per day from the start of the experiment— the subject's weight increased by approximately 19 lbs!

How could they possibly eat less and still gain weight?

Insulin resistance.

With every meal eaten insulin is released but is unable to do its job of shuttling nutrients from the food to the cells for energy.

When the cells can’t absorb the glucose from food then it sits in the bloodstream. Because high levels of glucose in the blood is dangerous, the body quickly converts it to fat and safely stores it.

Also, when the presence of insulin is high it prevents the breakdown of fatty acids for energy.

As an added punch to the face amino acids from the protein you consume cannot be absorbed by the muscles which hinder muscle development and preservation.

Here’s a simplified explanation of how vicious a situation and cycle this causes...

  • Only a small portion of carbohydrates can be used for energy so the rest gets stored as body-fat.

  • Because body-fat is not being accessed for energy, carbs are needed to fill the energy gaps.

  • Carbohydrates get burned through quickly which results in another drop in energy.

  • A sudden drop in energy triggers the need to eat more carbs—which again are not being used for energy but instead stored as fat.

  • Muscles are not absorbing all the amino acids needed for muscle growth so, over time you lose muscle.

  • Muscle loss results in a lower metabolic rate. Lower energy expenditure leads to more body-fat accumulation.

In part 3 we’ll examine which hormones affect hunger.