Unpacking Fasting

Written by Veronica Yoo

The Progression of Fasting Benefits Over Time and Its Ideal Frequency

In recent years, fasting has transitioned from a ritualistic or spiritual practice to a celebrated wellness tool. As researchers delve deeper into understanding its numerous benefits, many wonder not just about the progression of these benefits, but also how frequently one should fast. Let’s embark on a comprehensive exploration of both.

Understanding Fasting: Setting the Stage

Before diving into the specifics, it’s important to understand what fasting means. In essence, it is abstaining from caloric consumption for a set period. But as the clock ticks on, our body undergoes a variety of physiological transformations.

The Initial 24 Hours: The Body’s Adaptation

Hour 1-12: The Glucose Phase: Our body first relies on glucose for energy. Post our last meal, the body utilizes glycogen, a form of glucose stored in the liver.

Insulin Dynamics: As fasting progresses, insulin secretion decreases. This decrease is particularly important for those battling insulin resistance or type 2 diabetes.

Hour 12-24: Entering Ketosis: With dwindling glycogen stores, the body starts converting fats into ketones for energy. This metabolic switch can offer cognitive benefits and potential therapeutic advantages for brain disorders.

Cellular Cleanup: Autophagy commences, a process where cells discard dysfunctional components, which has implications for disease prevention and longevity.

Day 2: Venturing Deeper

Hour 24-48: Fat as Primary Fuel: Fat reserves become the chief energy source, contributing to weight loss.

Managing Hunger: Contrary to popular belief, hunger might plateau or even reduce, as the body efficiently uses its fat reserves.

Heightened Mental Acuity: With increased ketone production, many individuals report improved focus and clarity.

Day 3 and Beyond: The Healing Phase

Hour 48-72: Enhanced Cellular Repair: The body intensifies autophagy, signaling a deeper restoration process.

Immune Revitalization: Emerging research hints at fasting’s potential in immune cell regeneration, offering an avenue to bolster defense mechanisms.

Extended Fasting (72 hours onwards): Optimized Fat Burning: Ketosis becomes more pronounced, often resulting in peak fat loss.

Cautionary Notes: Extended fasting can lead to nutrient deficiencies and, in some cases, muscle wastage. It’s imperative to be under medical supervision if one is considering fasting for this long.

How Often Should You Fast?

The frequency of fasting hinges on individual goals, health status, and comfort. Here are some popular fasting schedules:

  1. Intermittent Fasting (IF): This can be a daily affair, where one restricts eating to a particular window, say 8 hours, and fasts for the remaining 16.
  2. 5:2 Diet: This weekly approach involves eating normally for 5 days and drastically limiting calorie intake (about 500-600 calories) for 2 non-consecutive days.
  3. Alternate-Day Fasting: As the name suggests, one eats normally one day and fasts or consumes minimal calories the next.
  4. Extended Fasts: These are less frequent and can range from 3 days to even 30 days. Due to potential risks, they should always be supervised by healthcare professionals.

Factors to Consider:

  • Health Status: Individuals with certain medical conditions or those on specific medications should consult with healthcare providers before considering any fasting regimen.
  • Purpose of Fasting: If your goal is weight loss, intermittent fasting or the 5:2 approach might be ideal. For deeper cellular repair or spiritual reasons, extended fasts, though infrequent, can be considered.
  • Personal Comfort: Some people find daily intermittent fasting more aligned with their lifestyles, while others prefer the 5:2 method. It’s essential to find a rhythm that feels sustainable.


Fasting offers a unique lens to appreciate our body’s metabolic versatility. From glucose dependence to fat adaptation and heightened cellular repair, the fasting journey is a testament to our body’s inherent wisdom.

However, as with all health practices, it’s pivotal to approach fasting with knowledge and mindfulness. Whether it’s a brief daily fast or a prolonged one, the key is to listen to one’s body, be informed, and seek guidance when necessary. Through such a measured approach, fasting can indeed become a tool of rejuvenation, health optimization, and profound self-awareness.

Veronica Yoo

Veronica is dedicated and experienced nutritionist and certified health coach who specializes in functional medicine, She's a published author, nutritional instructor, WBFF professional figure athlete, and both the brains and beauty behind all that Makeover Nutrition offers.

Veronica is also the President & CEO of a BC based health and wellness association; Pacific Alliance of Body Care.