How Intermittent and Prolonged Fasting Can Improve Your Health

Many people swear by intermittent and prolonged fasting. They say it improves their digestion, energy levels, aids in fat loss, and more. 

Is there evidence to support these claims? Is intermittent fasting as beneficial as people say it is? Let’s find out. 

What is Intermittent Fasting?

Before diving into the benefits, I would like to briefly touch on what intermittent and prolonged fasting are. Intermittent fasting is a way of eating that divides the day into a fasting period and an eating period. During the fasting period, you consume nothing but water and during the eating period you eat. Intermittent fasting and fasting in general, mimic nature. Our hunter gather ancestors went longer periods of time without food between hunts or when food was scarce. Our bodies are actual adapted to do very well with fasting as you will see when we discuss the benefits. 

There are various lengths of fasting and eating times. The most common being a 16 hour fasting window and an 8 hour eating window. However some people fast for 18 hours and eat with in 6 hours or fast for 20 hours and eat with in 4 hours. It’s customizable but recommended that you fast for at least 16 hours to reap the benefits. Also it’s not necessary to do it every day, studies have shown that intermittent fasting just a few days a week still provides great benefits. 

However longer fasting windows and intermittent fasting more days each week generally provide more benefits as long as you fuel your body well enough during your eating window.

What is prolonged fasting?

A prolonged fast is a period of at least 24 hours where you consume nothing but water and some salt (the salt helps with electrolyte retention). Many people do 48 hour or 72 hour fasts, and sometimes even longer. Since these fasts are longer and more intense, they are done less often. Prolonged fasting is typically done anywhere from once a month to once every 3 months. 

Like intermittent fasting, prolonged fasting helps to mimic natural food scarcities. Food is not suppose to always be an arms distance away. A little fasting actually has lots of benefits, and increasing the length of fasts, exponential increases the benefits. 

Benefits of Fasting

1) Promotes Fat Burning-

Most of the time your body uses the food you eat for fuel, but when no food is coming in an alternate source, stored body fat, is used. (1, 2, 3)

2) Retain Muscle and Improve Body Composition-

It has been shown that fasting significantly increases human growth hormone (HGH) up to 5 times normal levels. HGH is a hormone important for muscle strength, weight loss, metabolism, and growth. This increase in HGH is believed to cause both fat loss and muscle retention leading to the preservation of your hard earned muscle as you burn fat. Resulting in a leaner body composition. (1, 3)

3) Mental Sharpness-

When fasting your body goes into survival mode. Since food appears to be scarce, your body conserves energy by becoming hyper focused on the task at hand. Traditionally this task was finding food, but you can direct this focus and attention towards whatever you’d like. (1)

4) Increase in Energy-

Energy is also increased due to an increase in mitochondria. The mitochondria are the organelles responsible for converting fat, carbs, and protein into energy. Even though you are not eating, you are still burning stored body fat and the increase in mitochondria leads to more fat burning and more energy. (1)        

5) Cellular Regeneration and Anti-aging-

Fasting increases autophagy (the body’s natural recycling process of old and damaged cells). Old cells are eaten by newer cells, consolidating them into stronger and more efficient cells. This causes skin to glow, increase organ function, increase lifespan, and decrease risk of diseases and cancer. (1, 3)

6) Reduced Risk of Diabetes-

In type 2 Diabetes the body becomes resistant to insulin due to constant high levels. This lowers insulins ability to transport glucose into cells which leads to high blood sugar and diabetes. Insulin is released in response to eating so by fasting, our bodies get a break from insulin and retain sensitivity to it’s effects. (1, 2, 3)

7) Reduced Inflammation-

Fasting has been shown to reduce oxidative stress and inflammation in the body. Inflammation is a root cause to many diseases and health problems such as autoimmune diseases and arthritis. Fasting has been shown to improve these conditions without the harmful side effects that come from anti-inflammatory drugs. (1, 2, 3)

8) Improve Memory-

Fasting increases brain-derived neurotrophic factor which is responsible for the survival and growth of new neurons (brain cells). This leads to an increase in brain cells primarily in the hippocampus (a region of the brain responsible for memory) which improves memory and decrease risk of Alzheimer’s. (1, 3)

9) Increase Stem Cell Production-

Stem cells are cells that do not yet have a purpose. They stand by and convert into whatever cells your body needs. That could be a nerve, bone, muscle, or fat cell. As we age our stem cell pool decreases making it harder for your body to repair. Fasting increases your stem cell count making you look and feel younger. (1)

10) Decrease Tumor and Cancer Growth-

After burning through your glycogen (stored glucose), your body turns to burning fat and producing ketones for energy. Tumors and Cancers live off glucose so by running on ketones you are starving and killing cancers and tumors. (1, 3)

11) Increased Cell Resistance to Stress-

When fasting your adrenals and cells increase their stress tolerance and become tougher. This is a unique survival mechanism that has been genetically established through years of past adaptation. (1)

How Fasting Length Impacts Benefits:

While fasting provides all the benefits we just talked about, certain fasting lengths optimize specific benefits. Intermittent Fasting and shorter fasts (roughly 24 hours) provide more metabolic benefits such as fat loss, muscle retention, improve body composition, mental sharpness, decrease inflammation, and decrease risk of diabetes. 

Metabolic Benefits are still high after 24 hours and around this time the longevity benefits start to become exponential. Longevity benefits include improved memory, reduced risk of cancer and tumors, increased stem cells, cellular regeneration and anti aging. The longer you fast, within reason, the more longevity benefits will increase. After a few days metabolic benefits will decrease and you will be getting mostly longevity benefits. 

When starting with fasting, it is important to ease into it. Start with shorter fasts and work your way up to longer ones. Fasting has so many benefits and can be a great addition to your health routine!

Works Cited

1. Berg, Eric. “Amazing Benefits of Prolonged Fasting.” drberg.com. 18 October 2018. https://www.drberg.com/blog/amazing-benefits-of-prolonged-fasting

2. “Does Eating Small Amounts Between Meals Help or Hurt Weight Loss?” YouTube, uploaded by Healthy with Nicole, 14 December 2019. https://www.youtube.com/watchmc_cid=20b754fc28&v=q3DkJyeN1wk&mc_eid=4503e8c7ce&utm_source=Healthy+With+Nicole+Followers&utm_term=0_e7356d622220b754fc28106229021&utm_medium=email&utm_campaign=20b754fc28EMAIL_CAMPAIGN_2019_04_22_01_46_COPY_01&feature=youtu.be&app=desktop

3. Gunnars, Kris. “10 Evidence-Based Health Benefits of Intermittent Fasting.” Healthline. 16 August 2016. https://www.healthline.com/nutrition/10-health-benefits-of-intermittent-fasting