What is Intermittent Fasting?

Over the last 30 years or so, we have been encouraged to consume smaller meals throughout the day to improve our health. This theory assumes that you are less likely to overeat if you are keeping a moderate level of satiety throughout the day. Your blood sugar levels will stay consistent as a result of consuming smaller meals, which can lead to feeling more energized throughout the day. Proponents of eating smaller meals throughout the day also claim that this can help us reach our natural set point weight. You may even burn additional calories simply through the act of frequent digestion¹.

That sounds good, right? Except the latest research indicates that theory may not be accurate. Researchers are continuing to study how the schedule of our food intake affects our metabolism and our biological health markers such as cholesterol, weight and insulin sensitivity. We are learning that eating more frequently does not necessarily lead to better overall health². There is evidence to suggest that intermittent fasting, or abstaining from food on a schedule, may actually improve our health markers and help us lose weight.

So what exactly is intermittent fasting? Intermittent fasting is an eating pattern that rotates between periods of eating and fasting. For this way of eating to be effective, you must abstain from eating for at least 16 hours at a time.

The simple idea behind this is that when our bodies are in a fasting state, they become more efficient at processing food and using energy. Research also suggests that when we eat less frequently, insulin does not need to be continuously released; which results in better insulin sensitivity at the receptor sites. This allows fat cells to release stored sugar and burn as forms of energy^2,3 leading to more efficient metabolism and possible weight-loss. This is a well-intended “side-effect” of intermittent fasting as blood sugar dysregulation often coincides with a multitude of chronic health conditions.

Intermittent fasting is most often used for weight loss, but it has also been shown to lower inflammation, improve cellular detox, and improve stress resistance. It can also help to reduce the instances of free radicals in the body; which lessens the chances of developing diseases such as cancer, diabetes, cardiovascular disease, and neurodegenerative brain diseases⁴. Lowering your risk for these diseases in turn can increase your lifespan. Intermittent fasting has also been shown to increase insulin sensitivity, which can help reduce inflammation and reduce metabolic stress that damages our cells.⁴.  

There are many ways to engage in intermittent fasting. They are differentiated by how long you refrain from eating. Here are some options to consider:

• 16-8: This is the most common option for intermittent fasting. This method involves adhering to a 16-hour fasting period and an 8-hour window on a daily basis.
• 5-2: This is the second most common option. For 5 consecutive days of the week you engage in your accustomed caloric intake. Then for 2 consecutive days of the week, restrict your caloric intake aiming for somewhere between 600-800 calories per day. 
• Days of fasting: In this method, you would select 1-2 days per week to fast, eating normally the remainder of the week.  
• Up to the 9th hour: This method is most similar to the 16-8 option listed above. In this case you would not begin eating until 9 hours after waking. Once you begin eating, consume all food within an 8-hour period. 
• One meal per day: This option is just as it sounds; you consume one meal per day. The size of the meal is up to your discretion.

Changing up what we eat and when we eat can be a tricky change to navigate! At first you may feel extremely hungry and eat more than you need. To overcome this, work to eat a whole-food based diet with healthy fats, clean proteins and plenty of fruit and vegetables. This will likely help you to stay fuller for longer. Our body is better at recognizing hunger and fullness cues when we consume whole foods. While intermittent fasting can be used for weight loss, its biggest benefit is its ability to decrease inflammation and improve overall health.  

Intermittent fasting is not for everyone, as it requires keeping rules around food. It may not be a healthy choice for someone who has experienced disordered eating habits. If you are wondering if this is the right option for you, it is important to first consult your primary care physician before making drastic diet changes.  

Book an appointment with Dr. Chang today if you are interested in discussing whether this option is right for you!

1.         Aljuraiban GS, Chan Q, Oude Griep LM, et al. The Impact of Eating Frequency and Time of Intake on Nutrient Quality and Body Mass Index: The INTERMAP Study, a Population-Based Study. Journal of the Academy of Nutrition and Dietetics. 2015;115(4):528-536.e1. doi:10.1016/j.jand.2014.11.017
2.         Sutton EF, Beyl R, Early KS, Cefalu WT, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism. 2018;27(6):1212-1221.e3. doi:10.1016/j.cmet.2018.04.010
3.         Munsters MJM, Saris WHM. Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males. Hennige AM, ed. PLoS ONE. 2012;7(6):e38632. doi:10.1371/journal.pone.0038632
4.         de Cabo R, Mattson MP. Effects of intermittent fasting on health, aging, and disease. Longo DL, ed. New England Journal of Medicine. 2019;381(26):2541-2551. doi:10.1056/NEJMra1905136

Author

Dr. David Chang ND, LAc David Chang, ND, LAc, is a board-licensed naturopathic physician and acupuncturist with extensive training in Naturopathic primary care and classical Chinese medicine. With more than six years of professional experience and a strong interest in chronic pain management, he is proud to own and operate his practice in Portland, Oregon.