Intermittent Fasting Regulates Hormones: Here’s How

Intermittent fasting balances hormones

Intermittent Fasting Regulates Hormones: Here’s How

Fasting allows your organs to rest, especially your liver, which is crucial for naturally balancing hormones


Insulin resistance is defined as the accumulation in tissues that are not designed to store fat (mainly the muscle and liver) People with insulin resistance have cells throughout their bodies that don’t use insulin effectively. This means the cells have trouble absorbing glucose, which causes a buildup of sugar in their blood. Low insulin sensitivity or higher insulin resistance means that you have less ability to absorb glucose and subsequently protein that is also insulinogenic. Basically saying that it’s harder to get the net positive effect of recovery from working out/eating healthy.

Fasting and Insulin

When you fast for an extended period of time, the fat deposits that have accumulated over time become the fuel that cells need to operate. As a result, the size of the excess fat droplet gets smaller over time. As the size of the lipid droplet in muscle and liver cells decrease, those cells become more responsive to insulin. In other words, by reducing the size of the fat droplet, insulin becomes more powerful


HGH causes the chondrocyte cells of our cartilage to divide and multiply, which stimulates collagen synthesis in the skeletal muscle and tendons; improves physical capacity Additionally, HGH helps boost the immune system, breaks down lipids to reduce fat, and stimulates the liver to produce more glucose, which can keep blood sugar levels from dropping too much Growth hormone secretion decreases steadily with age, but one of the most potent stimuli to growth hormone secretion is fasting.

One study, published in the Western Journal of Medicine, looked at a single patient who decided to undergo a 40-day fast for religious purposes Saw a 1,250% increase in growth hormone and a shorter 5 day fast gave a 300% increase (2) Another study, from The Journal of Clinical Endocrinology and Metabolism, showed a 5-fold increase in HGH in response to a 2 day fast (3)


Cortisol is the so-called stress hormone. It mediates the ‘flight or fight response’ with help from the sympathetic nervous system – produced in response to stress and increases alertness and decreases the need for sleep

Cortisol is both a fat storing and fat burning hormone – it increases the activity of lipoprotein lipase (LPL), the body’s major fat storing enzyme and also increases the activity of hormone sensitive lipase (HSL), the body’s chief fat releasing enzyme (when elevated)

Cortisol is released during exercise and fasting periods in order to free fat stores so the body can burn them for energy

• So essentially, cortisol can be good when you’re in a fasted state, but can be bad when in a fed state as it simultaneously turns on fat burning and fat storage. One study looked at college women from the University of Virginia who fasted for 2 days – they experienced a 75% drop in leptin and a 50% increase in cortisol

Prolonged elevated levels of cortisol can have a few negative side effects: food cravings, increased anxiety, insomnia – hence why fasting for too long can have negative consequences


High levels of estrogen can result in gynecomastia, weight gain, and headaches

An enzyme called aromatase that is found in tissues throughout the body turns testosterone into estrogen

Aromatase is found in body fat, so those with higher body fat produce more aromatase and, therefore, have higher levels of estrogen and lower levels of testosterone (i.e. since fasting promotes fat loss there are lower levels of aromatase to be found)

A study published in the American Journal of Physiology found that fasting-induced autophagy increased the efficiency of the removal of toxins and estrogenic compounds – due to weight loss (4)

Blocking estrogen is definitely optimal as an abundance of estrogenic compounds only works against your testosterone levels


1) You Are “When” You Eat: The Benefits of Intermittent Fasting. (n.d.). Retrieved from…

2) Fasting: the history, pathophysiology and complications. – PubMed – NCBI. (n.d.). Retrieved from…

3) Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men. – PubMed – NCBI. (n.d.). Retrieved from…

4) Mitochondrial degradation by autophagy (mitophagy) in GFP-LC3 transgenic hepatocytes during nutrient deprivation. – PubMed – NCBI. (n.d.). Retrieved from…

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