Intermittent Fasting

What? Why? Who?

What is intermittent fasting? It is an eating plan where an individual switches between fasting and eating on a regular schedule. It doesn’t include any sort of macronutrient or calorie counting or nutrient/food alterations; just timing and length of eating verses not eating. Intermittent fasting has been around for a long time and has been practiced many different ways (days, hours, on/off, etc.) for many different reasons (religious, protests, treatment of disease, etc.). Most people already (from childhood) practice some form of intermittent fasting by not eating after dinner until breakfast the next morning.

Types of Structured Intermittent Fasting:

• Time Restricted Feeding (TRF)
  • At least 12-14 hours of fasting at night are needed to gain some of the potential benefits. For example: If you eat dinner at 6PM, you would eat breakfast between 6-8am.
  • 16:8 is fasting for 16 hours and eating within an 8 hour time frame. For example: If you eat dinner at 6PM, you would eat breakfast at 10am.
  • There is even a more aggressive approach of 20:4.
• Alternate-Day Fasting (ADF) is fasting 24 hours followed by eating throughout the next day and back and forth.
  • Alternate-Day Modified Fasting (ADMF) can include consuming bone broth, coffee, tea (<200 calories from mostly protein/fat) on the fasting day.
• Periodic fasting/prolonged fasting (PF) usually used for religious reasons.
• One Meal a Day (OMAD)– not recommended
• KetoFast is essentially doing a ketogenic diet and entering ketosis.

* The timing of the fast is best if aligned within sunrise and sunset to be in balance with your metabolic circadian rhythm. Higher food intake in the am and lower food intake in the pm optimizes health outcomes. Research has shown that nighttime eating (between 5pm-midnight) may lead to overconsumption of calories and increased markers of inflammation.

*For individuals fasting for longer times, consuming adequate protein and electrolytes during the feeding time is essential!

Why intermittent fasting?

When we are eating, we are driving our bodies anabolic processes (growing and building molecules) which include mineralization and growth of bone and building muscle just to name a couple.

When we are fasting, we drive autophagy which is the orderly degradation and recycling of cellular components for cellular repair and formation of new cells. It helps in removing cellular waste and intracellular pathogens. This helps keep cells healthy! Autophagy is shown to happen closer to the 16 hour fasting window.

IF can lower oxidative stress and inflammation.

Possible benefits of IF and the gut microbiome/digestive system:

• activates the gut-brain connection
• promotes epithelial integrity (heals the lining of your intestines)
• promotes energy homeostasis (increases short chain fatty acid (butyrate) production which is the main energy source for our intestinal cells)
• suppresses inflammation and oxidative stress
• increases microbial diversity and richness
• aids in pathogen battle and removal (ex. after a stomach virus)

*more studies are still needed to determine long term effects of IF

Who may or may not benefit from Intermittent fasting?

Some potential side effects from any form of fasting: fatigue, headaches, lightheadedness, irritability, hunger, constipation, gas, and bloating.

Intermittent fasting can have its benefits, but is not beneficial for everyone. *I want to highlight that fasting is a stressor on our bodies- if you can’t take on additional stress (even a potentially good stressor), fasting is not for you at this time. Part of the effectiveness is whether someone can practice it long term, so it has to be the right fit. Also, to note, most studies have only been on animals or short term human studies.

If wanting to implement more of a consistent longer fasted state to your routine, start small. If you are not at 12 hours, get to 12 hours first, then work your way to 14 or 16. In most cases there is no need to go more than that on a regular basis. Or maybe your focus isn’t on the length of the fast at all, rather the timing to stop eating to help symptoms associated with GERD (reflux) or gastroparesis (slowed stomach emptying) by moving your dinner earlier (5-7pm)and not snacking after.

This blog post is intended to fill you in a little about what intermittent fasting is, some of the types, some of the possible benefits and drawbacks, and tips on implementation. If wanting to use IF to improve a health condition, its important to inform your doctor and get advice from a trusted provider who is knowledgeable about IF.