Insulin, Leptin, Ghrelin: Explained in Plain English 

Are you trying to lose weight? Here’s a quick guide to how your body regulates stored fat – explained in plain English.  

The key point is that our appetite and weight loss/gain are all regulated by hormones. 

This is why the calories in/calories out model does not work for long-term weight loss. 

Obesity is not a calorie problem. It’s a hormonal problem. 

You’ve probably already heard about insulin and the role it plays in obesity and weight loss.

But insulin is not the only factor! Leptin and ghrelin are also major players. 

Let’s take a look at these three powerful hormones and what you need to know. 

Insulin 

Insulin is the hormone we hear most about in the Fasting and Keto world. And for good reason. 

Because when insulin is present, the body is not burning fat. The body stores fat in the presence of insulin.

When you eat, insulin is released.

How much insulin and how often depends on the kinds of foods you’re eating and when you’re eating them. 

Carbohydrates trigger a bigger insulin response than protein or fat. 

And if you’re eating around the clock, you’re stimulating insulin around the clock, too. 

This is why fasting works, because when you’re not eating, insulin is not present, and the body can burn fat.

Ghrelin

Ghrelin is the hormone that tells you it’s time to eat. 

When you feel hungry, you can be sure ghrelin is on the move. 

You might think that fasting would mean that ghrelin is present constantly, but that is not the case.

When fasting, ghrelin comes in waves, usually coinciding with your normal meal times.

But the hunger hormone is not a bad thing! 

Ghrelin triggers HGH (Human Growth Hormone), which is why muscle loss is not an issue during fasting. 

And ghrelin suppresses insulin, helping to promote fat burning. 

Leptin 

On the other side of the spectrum, leptin is the hormone that tells your body it’s full. 

Leptin helps you maintain a healthy weight by keeping your appetite in check. 

Unfortunately, many of us have become less sensitive to leptin. 

We’ve lost touch with our body’s built in system that is designed to keep us at our perfect weight. 

As a result, we don’t always get the message that we’re full. 

Leptin, like insulin, also tells the body to store fat.

How do these hormones work together?

When everything is working like it should, these hormones balance each other out.

When ghrelin is up, insulin and leptin are down, and fat burning is turned on. 

When insulin and leptin are up, ghrelin is down, and the body is storing fat.

Ghrelin says, “Hey, want some food?” and when you’re full, leptin says, “Stop eating.”

It’s a highly efficient system. But that’s not how it always goes. 

Enter the Standard Western Diet 

Eating a diet high in carbohydrates, and eating around the clock, throws that efficient hormonal system out of balance. It starts with insulin resistance which in turn disbalances the other two. 

We become less sensitive to these hormones. 

Our appetite signals no longer work, resulting in food addictions, obesity, and metabolic diseases. 

What now?

No matter how out of whack things have gotten, there are ways to rebalance these important hormones. 

Fasting 

Including some form of fasting in your lifestyle is a fantastic first step!

While you’re fasting, insulin and leptin levels are both down.

This helps you to become more sensitive to them so that they can do their jobs more efficiently. 

And ghrelin with all its benefits increases during fasting. 

Keto Diet

A diet high in carbohydrates keeps insulin and leptin levels higher longer. 

Choosing a Keto Diet when not fasting will balance those hormones and help keep you in fat burning mode, instead of fat storage. 

Exercise 

Physical activity helps to burn up glucose, so your hormones don’t have to work so hard to do their jobs efficiently. 

And all of these–fasting, Keto, and exercise–can lead to weight loss, a result of those hormones becoming much more balanced. 

The body knows what to do!

Insulin, ghrelin, and leptin (and other hormones) make up an amazing system designed to keep you in optimal health. 

Incorporating things like fasting, Keto, and exercise, can get you back in touch with those built-in appetite signals and help you maintain a healthy weight.

Author: Roo Black

Roo Black

Roo is a fasting coach with over 5 years of experience. She leads the admin team of the Official Fasting for Weight Loss Facebook group – one of the largest fasting communities on social media with over 125,000 members. We highly recommend this group for anyone who is looking for fasting advice or coaching.

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