Fasting has become a popular trend in dieting and health. You have probably heard a friend or two say: “I am doing intermittent fasting.” This article will discuss why this term needs to be abandoned. I will also offer a more accurate description of all the common fasting protocols.

Fasting is consistent with our evolutionary history. The thrifty gene hypothesis describes how we experienced brief moments of abundant food punctuated by long moments of scarcity. Our bodies adapted to this environmental stimulus and used it to enhance health – growth during abundance with recycling, regeneration, and renewal during scarcity. This cycling back and forth is considered by many experts to be an ideal way to maintain health.

Fasting, once thought to be religious/spiritual radicalism, is now an accepted method of maintaining health. In our obesogenic society the abundance of high-calorie, low-nutrition, addictive foods, constantly turns on your pro-growth, pro-aging, pro-inflammation, pro-disease pathways. This is the underlying cause of the obesity and all chronic diseases. Fasting is a great tool to restore balance. The following clarifies the nomenclature.


IF has joined the popular lexicon and is typically misapplied or misunderstood. It is when you limit food intake intermittently. This term is falling out of favor due to its overuse, improper use, and lack of specificity. Theoretically, anytime you are not eating you are fasting – between lunch and dinner for instance. The word breakfast comes from – breaking a fast. Let’s agree to be more specific, especially when discussing the important topic of health.


CR is the prolonged decrease in calories by 25- 30%. This was made popular by the pioneering work by Roy Wolford. This method showed initial promise with dramatic health benefits. Long-term, however, compliance was minimal and the people who did stick with it showed poor wound healing, decreased immune function and chronic stress.


TRE this is eating in accordance with your circadian clock. The work of Sachin Panda at the Salk institute has demonstrated health benefits from restricting food intake to 9-12 hours a day, ideally, have your last meal be three hours before bed. Some research studies indicate that narrowing your eating window to less than eight hours a day may lead to an increase in gall stones. Some people refer to this as IF; it is actually intermittent eating. This is the natural evolutionary method of eating. A sixteen-hour eating window is unhealthy.


PF is when you have eliminated calories long enough to have created a metabolic shift in your body called ketosis. Ketosis is when you switch to using fat for energy rather than just glucose (glycogen). This is also called beta-oxidation. This must happen on any diet where you are trying to lose weight. Fasting accelerates that process and the initiation of ketosis. The onset of ketosis can vary from 8-48 hours and depends on multiple factors. The typical time frame for a PF is at least three days but can be and often is much longer. Fasts longer than 5-7 days should be done with expert supervision. DO NOT do prolonged fasting without consulting your physician and or a water fasting expert.


FMD advocates claim significant advantages over water-only prolonged fasting. The FMD is typically a five-day program that precisely titrates calories and macronutrients to allow the user to consume limited calories while still getting the benefits of fasting. Water-only fasting has significant benefits, but, should be done in an activity-limited, medically controlled environment. FMD advocates claim the following advantages over water only fasting:

  • Improved compliance.
  • Healthy fats encourage greater stem cell generation.
  • Although strenuous activity is not advised, you can continue normal daily activities.
  • Spares muscle and bone.
  • Fasting is the only known physiologic interruption of sleep. One night of short sleep has a dramatic effect on health and safety. With an FMD you attenuate the impact on your normal sleep cycles.

Fasting is becoming widely accepted by the health and wellness community. Some forward-thinking traditional physicians are adopting the practice as well. It is not a cure-all and must be entered into with education and caution. It is, however, a powerful intervention with very little downside that is here to stay. As we get more sophisticated with its use lets abandon the term intermittent fasting for a more accurate and descriptive terminology.

Dr. Steven Cangiano began his college career with aspirations to become a high school teacher. These aspirations took a turn when he decided to follow in his father’s footsteps and go into the field of podiatric surgery. He completed his medical school training at Temple University and his surgical residency at the NY College of Podiatric Medicine where he was chief resident. He continued his academic career and fulfilled his early teaching aspirations by becoming an assistant professor of surgery at the age of 27. He was board certified in foot and ankle surgery at the age of 28. As residency director of the Franciscan Health System of NJ, Dr. Cangiano grew the program into the largest in NJ. Dr. Cangiano published multiple articles in medical journals and spent a total of thirteen years in academic medicine before venturing off into the world of complementary medicine.