8 Things You Didn't Know About Fasting

Updated: Mar 4, 2019

Before I got into the health and fitness industry I tried a multitude of rather insane methods to lose weight. One of those was a "Master Cleanse" where I only drank a water, lemon juice, cayenne pepper concoction for two weeks straight. Yeah, I know. Insane. I'm just glad I'm off the crazy yo-yo diet train now.

But one thing I didn't realize I was doing during that "diet" was unlocking some of the powerful benefits of placing my body into ketosis. Two weeks is a little crazy, but doing a 2-3 day fast every month can unlock some key benefits to our bodies.

When I talk to my clients about trying a fast I usually get blank stares or they run and never come back. Our society and physicians have conditioned us to think of fasting as dangerous to our health and any feeling of hunger is a sign of starvation. In reality, the opposite is the case because when in a fasted state, your physiology is in an altered state that empowers and nourishes.

Fitness gurus and medical doctors mostly preach the doctrine of consuming several small meals throughout the day. Is it wrong? Definitely not and it may work in some instances, but the vast majority of the population would benefit greatly from eating LESS FREQUENTLY.

Doing daily intermittent fasting (IF) is already a great starting point for reaping the benefits fasting ketosis but there are many others uniquely characteristic to an extended fast that lasts for 24+ hours.

When tapped into a physiologically fasted state, the body goes through a series of adaptations:

#1 Cellular Detoxification and Repair

While our bodies are in a "fed" state (meaning we are eating regularly), it doesn’t have the desire nor the need to conduct a thorough cleansing. The main mechanism for this is ‘autophagy.’

‘Autophagy’ is a metabolic pathway that causes the organism to ‘self-digest’ itself and removes waste material from the cells. Autophagy is required to maintain lean body mass and it actually inhibits the breakdown of muscle in adults. It’s also needed for healthy brain cell mitochondia. In the process, inflammation throughout the body and overall oxidative stress get reduced. This fights against all illnesses and it’s the best thing about intermittent fasting.

Increased levels of glucose, insulin, and proteins all turn off autophagy. Even as little as 3 grams of the amino acid leucine can do so. To release autophagy, your liver glycogen stores need to be depleted first. This takes up to 14-20 hours of not eating. However, this pathway will only reach its peak after fasting for 2+ days.

#2 Boosts Growth Hormone and Retains Muscle

While fasting, the body shifts into a state of nutritional ketosis which is characterized by the production and utilization of an increasing amount of fatty acids and ketone bodies. This will torch fat burning as you’ll be drawing all of your fuel from the adipose tissue.

It also means that extended fasts aren’t as catabolic as you might think. The biggest fear people have in regards with fasting is that they will lose their muscle. This won’t happen because:

Ketosis is an anti-catabolic state that decreases the body’s need for glucose and makes you gain all of your energy from your own stored fat. Ketone bodies may rise up to 70-fold during prolonged fasting. Fasting triggers Human Growth Hormone (HGH), which is the hormone responsible for the building, maintenance and preservation of lean tissue, including skeletal muscle, cells, and organs.

In fact, HGH increases within the first 16+ hours by an astonishing 1300-2000%. Only after extremely extended fasts, such as 10+ days will you see HGH flatting out.

Moral of the story: 3 day fast muscle loss – ZERO

#3 Increased Metabolism

Contrary to popular belief, intermittent fasting doesn’t slow down the metabolism but actually increases it by 3.6% after the first 48 hours. Even further, 4 days in, resting energy expenditure increases up to 14%.

Instead of slowing down the metabolism, fasting boosts your metabolism and puts it into higher gear temporarily. This is probably caused by our ancestors increased adrenaline so that they would have more energy to go out into the savannah and find some food.

Although you may experience an initial slump in your metabolism, it isn’t necessarily a bad thing nor a sign of fat gain. It’s just that, after you stop eating, your body becomes more conservative with its fuel.

#4 Better Biomarkers

There are a host of health benefits accompanied by the absence of food The key contributing factor to this is insulin. It’s the key hormone in regards to the storage and distribution of nutrients in the body.

Insulin gets released by the pancreas in response to food intake. When blood sugar levels start to rise, insulin gets unleashed and unlocks the cell receptors for the sugar to enter them. The purpose is to store energy and prevent having elevated blood glucose levels for too long.

Most modern cardiovascular diseases are caused by constantly high blood sugar and insulin levels. To overcome this issue, you would want to keep insulin as low as possible and fasting is the surest way of doing so.

Fasting will:

  • Fight diabetes and lowers blood sugar levels

  • Improves insulin sensitivity, meaning it makes your insulin work more effectively

  • Reverses insulin resistance, which is characterized by an irresponsive insulin, leaving your blood sugar elevated for a long time

  • Reduces cholesterol because while fasting, you’re not consuming any carbs and the liver will thus decrease its synthesis of triglycerides

  • Promotes the growth of stem cells that increase longevity

  • There are also many studies showing how caloric restriction and fasting promote lifespan in many species, potentially in humans as well

#6 Protection Against Cancer and Tumors

On a similar note, autophagy can also purge precancerous cells and cause the apoptosis (cellular death) of malignant tumors. This gets triggered by fasting for an extended period of time.

Dr. Dominic D’Agostino is the leading expert in the field of research on cancer, fasting, and nutritional ketosis. He advises everyone to have a therapeutic fast that lasts for 3-5 days, at least 2-3 times per year. In so doing, you’re conducting deep cellular cleansing that will reduce your risk of cancer by a huge margin. Even if you’re healthy you would still want to take some preventative measures towards disease.

#7 And Neurodegenerative Disease

Fasting also increases levels of a hormone called ‘brain-derived neurotrophic factor’ (BDNF), a deficiency of which has been implicated in depression and various other similar problems. New brain neurons get formulated, which is a process called ‘neurogenesis.’ What’s more, neuroplasticity – the brain’s ability to form neural connections – benefits from this as well due to BDNF.

All that being said, fasting bolsters brain power and gives protection for neurodegenerative disease while mitigating cognitive decline.

#8 Lengthened Life-Span

By the same token, fasting improves longevity. If autophagy and HGH are running rampant, then your body will experience less oxidative stress and inflammation, including ‘sarcopenia’ (muscle loss) which are one of the biggest contributing factors to aging.

Fasting induces oxidative stress because of producing a surge in free radicals – the molecules mostly associated with aging. This further stimulates a gene called SIRT3 to increase the production of ‘sirtuins,’ which are protective proteins of longevity. In mice, they extend lifespan. There are no studies in humans but the effects may be similar.

The rise in free radicals is actually beneficial because they trigger protective pathways. If the body is intermittently exposed to low levels of oxidative stress it can build a better response and cope with it better.

When you abstain an organism from calories for a certain period of time, their expected lifespan will increase by 30%, but they will eventually still starve to death. The key to actually gaining any benefits from this abstinence is to do it intermittently.

So in short, fasting has far more benefits than weight loss...but the weight loss is definitely a fun win! Check out the results from my last 60 hour fast!

If you want to join me on my next 60 hour monthly supported fast which is powered by ketones and bone broth, be sure to join my VIP list to get the details! Be sure to click which option your're interested in learning more about and I'll send you a Keto Kickstart Guide for FREE!

If you're ready to start fasting now you can grab your detox kit or join the waitlist here!


[i] Short-term fasting induces profound neuronal autophagy. Autophagy. 2010 Aug 16; 6(6): 702–710.

[ii] Autophagy is required to maintain muscle mass. Cell Metab. 2009 Dec;10(6):507-15

[iii] Inflammation-Induced Alteration of Astrocyte Mitochondrial Dynamics Requires Autophagy for Mitochondrial Network Maintenance. Cell Metabolism Volume 18, Issue 6, p844–859, 3 December 2013

[iv] Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free Radic Biol Med. 2007 Mar 1;42(5):665-74.

[v] Owen OE, Felig P, Morgan AP, et al: Liver and kidney metabolism during prolonged starvation. J Clin Invest 1969 Mar; 48:574-583

[vi] Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. J Clin Invest. 1988 Apr; 81(4): 968–975.

[vii] Merimee TJ, Fineberg SE: Growth hormone secretion in starvation: A reassessment. J Clin Endocrinol Metab 1974 Aug; 39:385-386

[viii] Palmblad J, Levi L, Burger A, et al: Effects of total energy withdrawal (fasting) on the levels of growth hormone, thyrotropin, cortisol, adrenaline, noradrenaline, T4, T3, and rT3 in healthy males. Acta Med Scand 1977; 201:15-22

[ix] Enhanced thermogenic response to epinephrine after 48-h starvation in humans. Am J Physiol. 1990 Jan;258(1 Pt 2):R87-93.

[x] Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000 Jun;71(6):1511-5.

[xi] Dietary restriction increases the number of newly generated neural cells, and induces BDNF expression, in the dentate gyrus of rats. J Mol Neurosci. 2000 Oct;15(2):99-108.

[xii] https://www.ncbi.nlm.nih.gov/pubmed/16011467

[xiii] Practicality of Intermittent Fasting in Humans and its Effect on Oxidative Stress and Genes Related to Aging and Metabolism. Rejuvenation Research Volume: 18 Issue 2: April 21, 2015

[xiv] Bloom WL: Fasting as an introduction to the treatment of obesity. Metabolism 1959 May; 8:214-220

[xv] Bloom WL: Inhibition of salt excretion by carbohydrate. Arch Intern Med 1962 Jan; 109:80-86 48.

Veverbrants E, Arky RA: Effects of fasting and refeedingI. Studies on sodium, potassiulm and water excretion on a constant electrolyte and fluid intake. J Clin Endocrinol 1969 Jan; 29:55-62 49.

Botulter PR, Hoffman RS, Arky RA: Pattern of sodiuLm excretion accompanying starvation. Metabolism 1973 May; 22: 675-683