Functional Versus Therapeutic Fasting

In the United States, fasting is rising to a new level of acceptance and popularity that has never been seen before. For those of us that have been in the game and have been practicing and teaching fasting for a long time, it is nothing less than amazing to see and experience.

As fasting becomes more popular and is embraced by more people, it is important to make some specific distinctions in the lexicon and terms used with fasting.

Therapeutic fasting is simply a targeted approach where fasting is used to achieve a specific outcome, usually to heal one or more significant health problems.

Therapeutic fasts are normally quite strict and allow only water to be consumed while restricting physical activity. In some extreme cases, movement may even be eliminated altogether. A health professional also traditionally coordinates or supervises therapeutic fasts.

I like to call the practice of incorporating various fasting models into your normal lifestyle Functional Fasting. The Functional Fasting model normally uses a more flexible structure in terms of what can be used or consumed during the fast.

Some examples of functional fasting are:

  • Eating windows. This is when your eating for the day is limited to a set number of hours, with windows usually set for between 4 and 8 hours.

  • With intermittent fasting, either breakfast or dinner is skipped. This results in extending the time without food overnight while you are sleeping.

  • Alternate Day Eating (ADE) involves eating normally one day and eating nothing the next day, or eating normally one day and limiting the next day’s food intake to one regular meal and one half-sized meal. This is discussed in detail in the book “The Every Other Day Diet” by Dr. Varady.

  • Extended fasting is where a fast lasts 2 or more consecutive days. Extended fasting can last anything from 2 days to as long as 30 days, or even longer.

There are also various types of caloric restrictive fasting models such as:

Pseudo Fasting. This is similar to ADE and restricts the amount of food consumed to between 500 and 800 calories per day, without any day skipping. This model is also known as a “Very Low-Calorie Diet” (VLCD) and is often promoted by Dr. Jason Fung in his model and books.

The “Fasting Mimicking Diet” model was developed from research by Dr. Valter Longo where he uses a VLCD that is designed with low insulin-producing foods and is promoted in his Longevity Diet books.

It might also be argued that Keto Diets, High Fat Diets (HFD), and the Carnivore Diet are all types of fasting-mimicking diets due to the fact that the state of nutritional ketosis they promote in the body mimics the metabolic profile of fasting.

Functional fasting can include different versions of the fasts described above that allow drinks, and at times food items during the fast, and do not necessarily restrict activity or require rest while doing them.

I personally use and teach a Functional Fasting model in what I call a “Fasting Rotation.” The Insulin Friendly Lifestyle and Rotational Fasting makes use of a calendar where we plan our 6-month program out week by week, with no consecutive weeks repeating, and using all or any combination of the fasting methods described above.

I have done this for a long time with thousands of people in large groups in the population health space, as well as in my 1 on 1 program and in small groups.

That experience, continued study and collaboration with other doctors and practitioners that use fasting protocols, and consulting with each of the authors mentioned above, has resulted in us gathering a significant amount of data on the practice of fasting. This data includes information on the benefits of fasting, who likes and completes them, who doesn’t like them and why, which fasts are more efficient, and, most importantly, which fasting methods work the best together with other healthy lifestyle modifications to magnify the results.

This is what makes my approach different, much less difficult to implement and so much more effective in the short term, as well as for a Lifestyle option in the long term.

Whether you choose to work with me or decide to use somebody else’s model, always keep an open mind and work with a professional to guide you.

Ask any questions you have on this article by using the comments for this post and make sure you tag me if you want my 2 cents worth!

We can do better!