Episode Details

Episode 179: Impact of intermittent fasting Impact on T2DM

Future Dr. Carlisle explains the physiology of fasting and how it can help revert type 2 diabetes. Dr. Arreaza adds details on how to do intermittent fasting. 

Written by Cameron Carlisle, MSIV, Ross University School of Medicine. Comments and edits by Hector Arreaza, MD, FAAFP.

You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.

What is type 2 Diabetes Mellitus (T2DM)?

-Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder characterized by insulin resistance and impaired glucose regulation. 

-This impaired regulation can lead to hyperglycemia, contributing to complications in a myriad of organs: heart, kidneys, eyes, nerves, etc. (target organs). According to the CDC, more than 38 million Americans have T2DM (about 1/10 people). 

-Multiple mechanisms are believed to contribute to insulin resistance in obese patients with T2DM, such as increased lipid deposition throughout the body and systemic inflammation.

What is Intermittent Fasting (IF)? 

Intermittent fasting (IF) has recently gained popularity as a dietary approach for health benefits, but it has been around for thousands of years. IF is an eating pattern that alternates between eating and fasting (no calories consumed) over a specific period of time. When you are fasting, you are allowed and encouraged to keep drinking water and non-caloric drinks, like coffee, tea, and even homemade bone broth.

-According to the International Food Information Council Foundation (IFIC), 10% of Americans engage in IF daily. 

-According to Mark Mattson, a neuroscientist and IF expert for over 25 years, a mechanism called “metabolic switching” is seen with IF. This is when your body runs out of glucose and starts burning fat (i.e., fatty oxidation). These metabolic changes can help protect your organs and reduce the risk of chronic conditions, like T2DM. 

Common IF methods: 

• Time-restricted eating: Most common method, involves eating within a specific time frame (e.g., the 16:8, 18:6, 12:12 method is also common.  [16:8 means you have 16 hours of fasting and 8 hours of eating.]
• Alternate-day fasting: Alternating between fasting days and normal eating days.  [Find more info in The Complete Guide to Fasting, by Jason Fung, who is a nephrologist, he explains that alternate-day is basically eating every other day, which would give 36 hours of fasting, but if you are a beginner you can try a 24 hours fasting, in short, not eating breakfast any day of the week and having lunch 4 days a week, and dinner every night.]
• 5:2 diet (aka periodic fasting): Maintaining a normal diet for 5 days, with 2 days (usually non-consecutive) of caloric restriction (25% of normal caloric intake; e.g., 500 calorie meal). 

IF is strongly believed to improve metabolic health in individuals with T2DM by reducing insulin resistance via increasing insulin sensitivity, promoting weight loss (patients with obesity and DM… AKA patients with diabesity), and enhancing lipolysis via fat oxidation.

While fasting, the body goes through several phases that affect how energy is metabolized. Between 0 and 4 hours after eating, the body enters a feeding state, using glucose as its main energy source. After fasting for 12-16 hours, the body enters ketosis and starts to use fat for energy. Within 24-36 hours, autophagy begins, a process that recycles damaged cells and allows for cellular repair. This