The Thermalist® Journal

The Thermalist® Journal

Share this post

The Thermalist® Journal
The Thermalist® Journal
Are Women Different When It Comes to Fasting?
Copy link
Facebook
Email
Notes
More

Are Women Different When It Comes to Fasting?

Dr. Susanna Søberg's avatar
Dr. Susanna Søberg
May 18, 2025
∙ Paid

Share this post

The Thermalist® Journal
The Thermalist® Journal
Are Women Different When It Comes to Fasting?
Copy link
Facebook
Email
Notes
More
Share

Yes—and for good reason.

Women have a more dynamic hormonal system than men, with monthly fluctuations in estrogen and progesterone that impact metabolism, insulin sensitivity, and energy availability. This means that fasting may affect women differently at different phases of their cycle—and differently still in perimenopause and post-menopause.

But we need to be clear: “different” doesn’t mean “damaging.”
It means we must consider context, duration, and individual response.


What Does the Science Say?

Surprisingly, much of the early fasting research was done on men or male animals. This has led to a knowledge gap that’s only recently starting to close.

1. Short-Term Fasting and Reproductive Hormones

In rodent studies, long-term caloric restriction has been shown to suppress ovulation and lower estrogen. However, these are not direct equivalents to time-restricted eating in humans.

In human females, short-term fasting (e.g., 12–16 hours per day) has not been shown to disrupt estrogen or reproductive hormones when done appropriately. The key factor appears to be energy availability—if fasting leads to overall undernourishment, the body may downregulate hormonal output, especially in women with low body fat or high stress.


Become an Exclusive Member

  • Full access to all exclusive content - choose monthly or yearly.

  • Access to archive (+80 of Susannas articles with tons of health protocols).

  • Founding Members: Besides all articles, you get the course - “Thermalist Method at Home”.

  • +70 pages E-magazine with the most popular health protocols from the latest year.

  • You can read all the benefits on becoming a Member HERE.

  • Gift a Membership to someone you care about HERE.

Upgrade to Paid

This post is for paid subscribers

Already a paid subscriber? Sign in
© 2025 Susanna Søberg, PhD
Privacy ∙ Terms ∙ Collection notice
Start writingGet the app
Substack is the home for great culture

Share

Copy link
Facebook
Email
Notes
More