Benefits Of Fasting

Written & Edited by: Drs. Andersen & Marisa

History of Fasting

The practice of fasting spans many centuries, cultures, and religions, and with it has come many different applications and beliefs. Humans have historically experienced famine and food scarcity time and again through thousands of years. We've evolved to utilize this opportunity as a means of detoxifying the body, recycling dysfunctional tissues to build healthy new cells, and allowing nature a space to rebalance our overall well-being that’s lost living in a world of abundance.

Fasting as a ritual developed independently in numerous regions around the world. Some of the earliest accounts of fasting relate to religious rituals, as often individuals or communities would fast in preparation for approaching deities or as a process of cleansing one’s soul… and many of these rituals continue today. Fasting has also been used to make political statements. Examples include Ghandi’s hunger strike in protest of British rule over India, the 1981 Irish hunger strike, and the Suffragette (aka Women’s Rights) movement of the 20th century.

Therapeutic fasting was documented as early as the 5th century BCE when Hippocrates recommended food and drink abstinence to treat certain ailments and has been used in medicine ever since. Notable authors on the subject over the last several centuries include Edward H. Dewey, Charles Haskell, Upton Sinclair, and more. While our understanding of the mechanisms of fasting have been greatly expanded upon in the last 100+ years, the art and practice of fasting remains timeless.

You can read more on the history of fasting here.

Types of Fasts

There are many different ways to fast depending on your lifestyle, occupation, and desired level of engagement. These include: Intermittent Fasting (14-18 hour daily fasts), One Meal a Day (OMD) fasting, Eat-Stop-Eat fasting (24-hour fast every 3-7 days with one meal every calendar day), Alternate Day Fasting (ADF; fast one day, eat the next, etc), 5/2 fasting (2 days fasting/week), & Prolonged fasting of 3+ days. Research is currently being conducted to determine the specific differences in these types of fasts, but it is already clear that they share many of the same benefits.

Types of Fasting

Fast-Mimicking Diet (FMD): Beginner

A reduced-calorie meal plan, developed in part by Dr. Valter Longo at the University of Southern California, designed to induce a physiologic fasting state with many of the benefits of more restrictive fasting regimens.

Juice & Broth Fasts: Intermediate to Advanced

The use of juice, broth, or a combination of the two to reduce caloric intake and provide easy to digest nutrients, allows for digestive system rest and system-wide repair throughout the body.

Water Fasting: Advanced

The use of water alone allows the body to focus on repair and regeneration without any digestive preoccupation.

Mechanism of Fasting

During a fast, the lack of sufficient caloric intake to energize the body initiates a cascade of events that allow the body to utilize evolutionary survival mechanisms that lead to a multitude of benefits in human health and overall wellbeing. When the body is deficient in glucose, stores of glycogen in the liver and muscle are broken down into glucose molecules for energy in a process called glycogenolysis. Once the glycogen stores have been depleted (~12 hours), due to inadequate caloric intake from fasting, the body resorts to breaking down proteins and triglycerides (fats) for energy (~12-18 hours). After that, your body transitions to forming ketones from fats (~18-24 hours) which begin to act as the primary energy source to perform bodily and daily functions. Adipose cells which store fats are also well known to act as storehouses for toxins. So, as you liberate these fats for energy, the toxins stored in these cells are freed as well, ready to be released from the body.

The lack of sufficient protein intake during a fast triggers the body, in its innate wisdom, to break down the most dysfunctional and diseased cells (think cancerous cells) first in a process known as Autophagy (~24-48 hours). This process not only recycles proteins into their constituent amino acids used in building new, healthy cells, it also reduces inflammation, and addresses many of the effects of aging, leading to a longer, healthier life.

After 48 hours the body enters into a long-term fasting state. First, Human Growth Hormone (HGH) levels surge, stimulating muscle repair and regeneration. In addition, hunger cues, mediated by a hormone called ghrelin, start to normalize as hormone fluctuation levels stabilize (48-54 hours) .

By roughly 54 hours your insulin levels are at their lowest levels, improving insulin receptor sensitivity that enhances overall metabolic rate leading to a healthier body fat percentage (ie. weight loss), further reductions in inflammation, as well as promoting additional autophagy and associated detoxification.

Finally, after 72 hours of fasting a hormone called Insulin-like Growth Factor-1 (IGF-1) decreases. This triggers stem cell production, creates new immune cells, and reduces oxidative stress, all known to help prevent aging and the diseases of affluence (cancer, diabetes, heart disease, cholesterol imbalance, and obesity).

Detoxification: The breakdown of cells, fats, and proteins to produce energy constitutes the detoxifying effect on the body as a whole by releasing stored toxins and recycling dysfunctional cells to rebuild healthy new ones. This process is literally at the heart of every benefit associated with fasting.