How An Intermittent Fasting Dietary Approach May Impact Hormone Health

There’s a lot of talk about intermittent fasting (IF) dietary approaches and their impact on hormone health. In fact, if you do a Google search for the term “intermittent fasting and hormone health,” you’ll find over seven million search results.

So, what’s the verdict? 

While there are over fifty different hormones in the body, today, we’re focusing on five we think you should know. Keep reading to learn the latest research on how intermittent fasting may impact these hormones.

5 Hormones to Know When Practicing IF:

1. Ghrelin: The Hunger Hormone

Ghrelin is a hormone produced by the cells of the stomach. Also called the “hunger hormone,” ghrelin not only stimulates the appetite but may also play a role in preventing muscle loss, regulating fat storage, and blood sugar homeostasis. 

A 2019 human study suggested that in a 16:8 TRE  intermittent fasting dietary approach, there was a decrease in ghrelin and a decrease in the desire to eat compared to those following a 12:12 TRE.

An older 2012 study showed similar results. Ghrelin levels were decreased during Ramadan fasting. 

 

2. Leptin: The Satiety Hormone

Leptin is known as the satiety hormone and is mainly produced by adipose or fat tissue. It works opposite of ghrelin to suppress appetite, reduce food intake, and promote energy metabolism from glucose and fat.

A 2017 literature review of the metabolic effects of intermittent fasting summarized that mostly all fasting approaches decreased leptin levels.  This was seen in both animal and human studies. 

When you eat, your leptin levels naturally rise, and when you’re hungry (such as in a fasted state), your leptin levels naturally fall. The decrease in Leptin is what may drive you to eat. 

 

3. Cortisol: The Stress Hormone

Cortisol is a hormone produced by the adrenal glands, which are small triangular-shaped glands that sit on top of each kidney. The hormone cortisol regulates the body’s stress response and promotes glucose and fat metabolism. For example, cortisol causes glucose and fat to be released into the body to give the heart, muscles, and other major organs a quick burst of energy.

Before thinking of stress as a “bad thing,” it should be mentioned that stress can also be good. Eustress is a type of positive stress that is fun, exhilarating, and invigorating. Examples of positive types of stress include exercising, receiving a job promotion, and the joyful planning of a vacation.  

A 2016 literature review suggested intermittent fasting may increase cortisol levels. An increase in cortisol levels doesn’t automatically mean you’re stressed; rather, your body is using glucose and fat for energy. However, some research on cortisol and an intermittent fasting dietary approach show other results.

A 2021 systematic review of time-restricted eating patterns showed that cortisol changes were present, but the results were inconclusive. Cortisol levels may be higher or lower depending on whether breakfast or dinner was the meal skipped during an intermittent fasting dietary approach.

 

4. Estrogen: A Sex Hormone

Estrogen is a hormone involved in male and female reproduction. Specifically for female reproductive health, estrogen prepares the body for the possibility to hold and sustain a fertilized egg every month. 

An older 2007 animal study suggested an intermittent fasting dietary approach may result in an abnormal menstrual cycle. However, a more recent 2021 study showed the opposite results. The findings suggested a 22-week intermittent fasting dietary approach improved the reproductive function of female mice.

Even though animal studies give useful information, human research is still warranted. A 2016 human literature review suggested fasting may improve female reproductive health and benefit menstruation, ovulation, and fertility. 

 

5. Insulin: A Blood Sugar Regulating Hormone

Type 2 diabetes is a type of diabetes that is caused by several factors, one of which is insulin resistance. Insulin is a hormone produced by the pancreas and is responsible for regulating glucose or blood sugar levels; however, with insulin resistance, the cells of the body don’t respond as they normally should to insulin.

Adhering to an intermittent fasting (IF) dietary approach may be a game-changer for persons with type 2 diabetes. A recent 2021 literature review suggests this dietary approach may decrease insulin resistance and may be recommended by healthcare providers. 

 

The Bottom Line:

An intermittent fasting dietary approach may impact hormone health. 

Given the number of hormones the body produces and the important work they do, remember it’s best to speak with a doctor if there are any concerns about how your hormones may respond to this dietary approach.  

 

Disclaimer: This blog provides general information and discussions about health and related subjects. The information and other content provided in this blog, website, or in any linked materials are not intended and should not be considered, or used as a substitute for, medical advice, diagnosis, or treatment. Always consult your medical provider before changing your dietary approach and eating habits.