The Effects of Intermittent Fasting On Your Hormones and Body

There’s been a lot of buzz happening around my first article on intermittent fasting and I wanted to do a follow up, but with a twist.

I asked Nick Sigma, a Wellness Coach and new recent friend, his take on IF and if he would tweak a few things.

Here’s his take on it in his own words. Enter Nick Sigma.

I.F. or Intermittent Fasting is on the rise again. The concept behind I.F. is simple: go without any nutrition for long periods of time. Only water is allowed during this period and yes, you will get hungry!

I.F. has a plethora of health benefits for the human body, including the obvious convenience of not having to think about cooking or meal planning which frees up your time and of course fat loss.

That being said, not everything works for everyone and because of that, some people tend to dismiss I.F. as another fad.

So does I.F. work?

Yes, it does BUT there are a few things to consider for optimal results, in order to keep your body healthy, your mind sharp and maintain muscle mass without a drop in energy levels.

As a Wellness Coach who does I.F. on a weekly basis and engages in strength training (mainly deadlifts), high energy levels, focus and muscle mass retention rank high on my list of priorities. I will explain that in a future article.

For those of you who are interested in the benefits of I.F. (see Mario’s complete article linked above) and its correlation to Hormone Optimization, the following section will focus on the effects of I.F. on your hormones.

We will also examine cases where I.F. can aggravate existing issues in people with hormonal imbalances. (In other words, you will learn who needs to avoid I.F.)

Positive effects of I.F. on your hormones and body

I.F. has a lot of positive benefits for the master hormones, more specifically:

1) Effect on Ghrelin levels

I.F. can increase Ghrelin, the hunger hormone which is produced in the stomach.

When we are hungry, Ghrelin levels go up and when we eat, they go down. So why do we want to increase Ghrelin since we will be hungry all the time?

  • High Ghrelin levels can increase learning, memory and subsequently our focus (study).
  • It also has a protective effect against anxiety and depression symptoms from high stress (study).
  • And three, see the next point below.

2) Effect on Growth Hormone levels

Higher Ghrelin levels tend to increase IGF-1 levels in the body which means better Growth Hormone levels (study).

Growth hormone is the hormone of anti-aging and is responsible for rebuilding tissues, joints, muscles and organs in your body. It is also responsible for a great deal of fat loss.

And let’s not forget that optimized Growth Hormone levels also mean better sleep!

3) Effect on leptin and insulin levels

I.F. can play a big role in leptin sensitivity (study). Leptin is the hormone that controls hunger signals and is produced by fat cells in the body.

By increasing leptin sensitivity you subsequently increase insulin sensitivity and your body is able to produce insulin more efficiently and thus make better use of sugar in the body and also burn redundant fat.

4) Effect on estrogen levels

By lowering body fat, I.F. can help with estrogen dominance.

Excess fat on your body is a mini-factory of estrogen since each fat molecule actually secretes its own estrogen for its maintenance.

In addition, high estrogen levels also tip the scale in the estrogen/testosterone ratio (to the favor of estrogen in men, and in the favor of testosterone in women) which leads to estrogen dominance.

Estrogen dominance is the reason men look more like women as they age (fat in the hip area) while testosterone dominance in women makes them look like men as they age (more facial hair, fat in the upper body etc.).

Not only that but high estrogen levels in men are linked with a variety of problems such as Low-T, Erectile Dysfunction (indirectly), prostate enlargement (indirectly) and of course cancer.

5) Effect on testosterone and estrogen levels

It is also good to mention that lower body fat means higher testosterone levels in men (study) and a balanced estrogen production in women.

Negative effects of I.F. on hormones and who needs to avoid I.F.

Let us now take a look at how I.F. can negatively impact your hormones and why it is not recommended for people with the following hormonal conditions:

a) Effect on Thyroid hormones

I.F. can potentially affect people negatively with a hyperactive thyroid (hyperthyroidism).

People with this condition produce an unnaturally high amount of hormones T3 or T4 or both and have a high metabolism by default which means that they have trouble putting on weight and keeping it on.

Having someone with hyperthyroidism without a doctor’s supervision take up I.F. is a recipe for disaster since these people are at high risk for osteoporosis, have low energy, and further weight loss.

On top of that, these people need adequate intake of calcium and Vitamin D (which is a hormone, not a vitamin as I have explained in a previous article).

If you have any kind of thyroid condition, speak to your doctor before taking up I.F. or undertaking any weird diets.

b) Effect on Cortisol hormone

I.F. can increase cortisol production.

Your body produces cortisol under stressful conditions to protect your joints and help with your survival.

Closely connected to the fight or flight syndrome, (which also involves secretion of other hormones from the adrenals) cortisol has the tasks of melting muscle and storing fat.

For example, if you are all of a sudden trapped under a rock, your body will melt your muscles and store fat to keep you alive for as long as possible.

Of course, we don’t all have the same cortisol production. Some produce more, others less and it depends on internal factors (genetics and your hormonal makeup) and external (nutrition and stress levels to name but a few).

I.F. can become a stressful condition for your body since your body is used to being fed and using that food for a variety of purposes in the body (glucose and fat for proper brain function and energy production, protein and fat for muscle building among others).

So if you are doing I.F. and find yourself in a stressful situation such as stuck in traffic, working too hard on a project or working out intensely, your body will eventually start producing more and more cortisol.

And as mentioned earlier, higher cortisol levels for long periods of time leads to muscle wasting and storing excess fat. Not exactly the look you were going for when you signed up for I.F., right?

Stressed people and people with anxiety have ‘naturally’ high cortisol levels and need to be very careful with I.F. as it can aggravate their anxiety. This is something I have personally experienced and a lot of my clients had a similar experience.

c) Effect on blood sugar levels

Adding to the previous point, high cortisol levels can impact blood sugar levels.

This can have a negative effect on people with blood sugar regulation issues as they may have a hypoglycemia episode.

So people with blood sugar imbalances need to stay away from I.F. or at least do it under medical supervision.

d) Effect on sleep quality

Speaking of blood sugar levels, let’s see how I.F. can negatively impact your sleep.

While I.F. can have a positive effect on G.H. and can help optimize Melatonin levels (the sleep hormone which I have covered in another article), it can also cause a drop of blood sugar levels in the middle of the night which will wake you up.

As someone who has battled with insomnia after 2 years in the Special Forces, I can tell you that keeping blood sugar levels from dropping has been essential in managing and optimizing the quality of my sleep.

If you are one of those people who tend to wake up easily in the middle of the night and need to eat a small meal before bed to keep yourself asleep, you might want to be careful with I.F.

Closing notes:

Intermittent Fasting is an amazing nutritional technique that can improve the quality of your life by positively regulating your hormones, shedding unwanted fat, keeping your mind sharp and saving a lot of precious time! You can find a very comprehensive article on Intermittent Fasting by Mario on this very blog.

I personally use I.F. on a weekly basis and most of my clients have benefited from it.

That being said, it may not be for everyone.

Since it can have a negative effect on certain hormones, people with any hormonal condition need to consult with their doctor before trying I.F. to keep them safe.

Don’t forget that your health is primarily in your hands. Do take it seriously and adapt a healthy way of eating and you will be on your way to live your life, strong, healthy and free!

About the Author:

Nick Sigma CWC is a Certified Wellness Coach, Eclectic Herbalist and Health writer.

Through his website Nick teaches stressed people how to get stronger, healthier and free by optimizing their nutrition, sleep, exercise and hormones with basic herbs, supplements and lifestyle changes.

© Copyright Nick Sigma. – 2016. All rights reserved and re-printed on with explicit permission.

Resources and Studies:


Growth Hormone :

Leptin sensitivity:

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