Intermittent Fasting: Can it Really Help You Lose Weight?

by Leah Geoghegan | Board-Certified Nurse Practitioner


Intermittent fasting has become increasing popular, gaining attention in the media over the past few years. Many patients have asked us about the data supporting fasting, and if it really is as powerful as people say. Here we hope to set the record straight on fasting and explain with evidence why this diet tool is so effective (not to mention affordable!).


Our bodies were designed for a hunter-gatherer lifestyle, where food was not routinely available. Fortunately, our bodies adapted to use the sporadic food supply to our advantage. Here is some evidence explaining how and why:


Fasting helps with weight loss.


Typically, our body uses sugar as its primary source of energy. With prolonged periods of fasting (16 hours or more), our body is in need of fuel but does not have any sugar to make it. In this situation, our body will make energy from stored fat called ketone bodies. So when you fast, your body burns off fat for energy, helping you lose stubborn belly fat.


Fasting helps with energy and detoxification.


Yup, that’s right—limiting your calories helps your body produce energy! This sounds counterintuitive, but let me explain. Fasting increases PGC-1a, a master regulator of our body’s mitochondria, the part of our cells that produces energy. PGC-1a primarily functions in the liver, the body’s epicenter for waste elimination. During a fasting state, PGC-1a is stimulated to produce antioxidants that remove waste products called reactive oxygen species in the body and repair mitochondrial dysfunction.


Fasting helps heal and repair our DNA.


When our body has restricted resources, it wants to use what it has wisely. In order to do this, fasting stimulates a process called autophagy in which our cells evaluate their functioning and kill themselves if they aren’t working properly. This helps eliminate cells that are harmful and, if unchecked, could lead to diseases like cancer. Recent studies by Dr. Valter Longo have shown that after clearing out the defective cells, the body will produce stem cells that help to heal and repair the DNA, reversing the wear and tear of aging on our genes.


Knowing this information about fasting, you can see how eating three meals a day or, worse yet, food grazing, can inhibit these important checks and balances in the body. If you are interested in learning more about intermittent fasting and setting up a diet plan, please consult with one of our providers. We are happy to help get you started and design a program that is right for you!


Want to learn more? Here are some recommended reads:


  • The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting by Jason Fung

  • The Longevity Diet by Valter Longo