In a nutshell, Intermittent Fasting refers to an eating regime where you cycle between periods of fasting and periods of eating.
The periods of eating are often referred to as an “eating window.”
There are dozens of combinations of Intermittent Fasting.
Here are a few of the most common fasting periods:
- 12 hour fasting. Normally you would stop eating at 7 or 8 PM on one day and not eat until 7 or 8 AM the next morning.
- 18 hour fasting. You would fast starting at 7 or 8 PM on one day and not eat until 12 or 1 PM the next day. Basically you are skipping breakfast. If you plan on doing this daily, you have a 7 hour eating window … from 12 noon until 7 PM.
Longer Fasts include:
- 24 hour fasting or one-meal-a-day fasting. Most people had dinner one day and then don’t eat until dinner (same time) the next day. Some people alternate eating one day and fasting the next day as a lifestyle, while others do the 24 hour fast one or two times a week.
- 36 hour fasting. If you finish dinner at 7 or 8 PM on the first day, you skip all meals on the second day and don’t eat again until 7 or 8 AM on the third day.
- 42 hour fasting. Finish dinner at 7 or 8 PM on the first day, do not eat at all on day 2 and on day 3 your eating window opens at 12 or 1 PM.
Even longer Fasts:
- Seven to Fourteen Day Fasts. Many people undertake longer fasts for religious or health reasons. There are compelling studies that show amazing health benefits from longer fasting periods. For example Dr. Janson Fung often starts his severely obese and diabetic patients off on a seven to fourteen day fast. He says that first of all it is easier than trying to ease into it, and secondly it results in a significant improvement in blood glucose levels much faster.
- Longer — up to a month or more.
The longest fast on record?
In the 1970’s under a Doctor’s supervision (and a pile of researchers collecting data), a man started fasting at the weight of 456 pounds. He fasted for 382 days having only water and some vitamin supplements.
He stopped when he got to 180 pounds … a total weight loss of 276 pounds.
Five years later he had maintained a weight of 198 pounds.
The magical thing about extended fasting is that once you get past the first two days, it gets easier and easier.
100 Day Challenge Fasting
For my 100 Day Challenge I have chosen to start off with two x 42 hour fasting periods a week.
From my previous experience with fasting, I did three or four 42-hour fasts and actually found them to be quite easy. I am certain that I found it easy because I had spent over a month ramping up by first following the Paleo Diet and getting rid of ALL sugar, grain products, beans, potatoes, and corn products. My next step was to lower my carb intake by switching over to the Keto Diet. So if anyone does this cold turkey, expect a bit of a challenge.
Here is what my planned schedule looks like:
On FASTING DAYS I can have coffee, tea and lots of water. NO sweeteners.
On EATING DAYS I am following the Ketogenic Diet. I can have up to two meals per day with 12 grams (net) Carbs per meal.
If you want to know MORE about Fasting (including fasting for Diabetics) the BEST book on the subject is Dr. Jason Fung’s Complete Guide to Fasting. You can read my review or go straight to Amazon.