How to Intermittent Fast: Main Methods of Fasting

The mice study from our previous post seems to provide ample evidence that there is immense health benefit to eating at a time our bodies are prepared for food. More and more studies reinforce the idea that intermittent fasting (IF) helps prevent cancer and cardiac disease, while improving overall mental and physical health.

Dr. Elizabeth Yurth of Boulder Longevity Institute sees IF quickly becoming the “next big thing” both in popular diet culture circles and medical journals based in science, if not already.

It is important to understand that intermittent fasting is not just another diet fad. It is an eating pattern that seeks to feed the body at the most efficient time. There are multiple types of intermittent fasting in addition to the greater lifestyle change called time-restricted eating.

  • Occasional meal skipping: This form of fasting is exactly what it sounds like - intentionally choosing to skip a meal here and there for the sake of an overall lower calorie intake.
  • Warrior diet: The warriors fast all day with one big meal at nightime. This is similar to time-restricted eating but can be extreme for some who require more meals or higher calorie intake.
  • Alternate day fasting: Fast today, eat tomorrow.
  • 5/2 fasting plan: Fast on Tuesdays and Thursdays (or whichever days work best for you). Eat normally on the other days of the week.
  • Eat, stop, eat: Fasting for 24 hours at a time. This allows us to begin and end fasts at optimal times.
  • Time-restricted eating (TRE): This fast limits eating to the most efficient eating times during the day. Time-restricted eating aligns with the theory that eating in the appropriate segment of your day/night cycle will result in better alignment with your Circadian Rhythm.

Typically, TRE allows eating between noon and 8:00 PM. Your last meal should be around 6:00 PM or 7:00 PM to ensure digestion is complete by the cutoff. A 16-hour fast is easily accomplished and TRE can be done regularly as a lifestyle change.

A sample TRE schedule looks like this:

  • Noon - Lunch as the first meal of the day
  • 4:00 PM - Snack
  • 6:00 PM - Dinner
  • 9:00 PM - No calorie and no sugar drink (water)

When we show this schedule, a couple of questions inevitably pop into the minds of the reader. Let’s address those below in a FAQ format.

Everyone knows breakfast is the most important meal of the day. Why is the first meal at noon?

This is one of those phrases that gets passed down with little to no evidence backing it up. In a study of breakfast eaters taking place from 2008 - 2014 participants tended to be heavier, stored excess fat, and had higher insulin resistance than those who did not eat breakfast.

My trainer told me I need to keep my metabolism active by eating as frequently as possible.

We do hate to argue with fitness experts but it sounds like you are getting bad advice. Eating spikes cortisol. This causes a surge in insulin and a subsequent crash. Insulin encourages fat storage and the cycle repeats itself. This leads to a predictable difficulty in losing weight and body fat.

I need food to get my workout in.

Generally, studies show fasted cardio workouts can aid fat loss. If you are lifting heavier weights, you may have difficulty with morning workouts.

If we are focusing on our Circadian Rhythm, it may behoove us to change when we workout to allow for both time-restricted eating and weightlifting. The natural clock suggest working out in the evening (around 5:00 PM) is likely more efficient.

I need food to take my vitamins. I cannot take them on an empty stomach.

Our suggestion would be to change when you take your vitamins. If you take a prescription medication that requires taking with food, consult your physician about changing the time you take the medicine.

The point is that time-restricted eating is possible for almost everyone. The science backs up its efficacy and almost every “excuse” for not doing it can be rebutted quite easily.

Take control of your “clock” and roll back the damage by eating during the most efficient window of the day. We have yet another opportunity to reset the clock and take back control of our health.