Choosing how long you want to do you fast for can be quite challenging. In order to figure this out you need to know your top priority, it can be ether one of these:

  • Fat loss
  • Getting in Ketosis
  • Lowering blood sugar
  • Autophagy

This article will nee a basic understanding on the following topics: Glucose, Insulin, HGH, Ketones, Autophagy.

12 hours

  • Lower glycogen
  • Lower blood glucose (blood sugar)
  • Ketosis is starting (but barely measurable)

18 hours

  • Your body is switching to fat burning mode
  • Ketone production
    • Ketones, like hormones, signal your body
      • More ketones means
        • less inflamation
        • promote DNA repair
  • Human Growth Hormone (HGH) and Brain-derived neurotropic factor (BDNF) are increasing
    • Promoting brain growth and repair (Create new Synapses using Neurogenisis)
  • Exercise will accelerate this process
  • Authopagy is getting started

24 hours

  • Autophagy is picking up speed 🚀
    • Your body is paying more attention to the resources its using (higher quality of work)
  • Ketones
  • AMPK, mTOR, NAD+

48 hours

  • Ketones
  • Autophagy
  • HGH (is up 500%) + BNDF
    • Brain repair
    • Longevity
    • Wound healing
    • Cardiovascular Health
  • Lowest point of insulin
    • Lower Inflamation
    • Reversing metabolic syndrome: Lower blood preasure, Reduce belly fat, Reduce cardiovascular risk
      • Metabolic syndrome is a group of conditions that can lead to heart disease, diabetes, stroke and other health problems. Metabolic syndrome is diagnosed when someone has three or more of these risk factors:
        • High blood glucose (sugar)
        • Low levels of HDL (“good”) cholesterol in the blood
        • High levels of triglycerides in the blood
        • Large waist circumference or “apple-shaped” body
        • High blood pressure

72 hours

  • Deeper levels of autophagy
  • Hematopoietic Stem Cell Regeniration & Rejuvenation
    • White Blood Cells (Immune cells)
    • Chemotherapy Protection

120 hours

  • Nothing new
  • Stabalizing everything
  • More time for
    • Fat burning
    • Cleanup & Repair
  • Cells will set new “Set Points”
    • Can help with finding your new “stable weight” -> If you have trouble keeping the weight off, you can reset your cells.

So what is best, for when, and why?

If you have reached most of your weight and health goals: 18 hours is fine. This can be achieved by simply skipping breakfast.

If you want to lose weight: Try 24 or 48 hour fasts. This is also sustainable on the long term. You can try alternate day fasting, or do 36 hour fasts by skipping breakfast on every second day as well.

Great for maintenance and decease prevention: The 72 hour fast is great to do every once in a while. You can do it every couple of weeks, until you reach your goals and then decrease the frequency. Once or twice a year is fine.

If you have trouble keeping the weight off: go do a 5-day fast to reset your cells. You can do this every couple of weeks

If you’re trying to reverse a severe condition: 3 to 5 days is great, but be sure to get enough nutrients.

I highly recommend watching this video by Dr. Sten Ekberg about what is happening when you fast.

I recently did my first 5-day fast, you can read about my experience here.