Intermittent Fasting: What Are the Benefits?


By. Dr. Bren Boston

Intermittent fasting (IF) has been associated with weight loss, improved brain health, improved energy, enhanced tissue healing, and longevity. Intermittent fasting can mean fasting for 16 hours overnight while eating during the remaining 8 hours during the day, or it can mean reducing your caloric intake to 500 cals/day for two non-consecutive days of the week while eating a normal healthy diet the other five days.

Research out of Johns Hopkins School of Medicine has shown that intermittent fasting is good for brain health. Fasting is a challenge to the brain, building coping responses that end up protecting the brain. After 12 hours of fasting, the glucose stored in the liver as glycogen is depleted, and the body starts to burn fat for energy. Burned fats release ketone bodies which, in small amounts, promote health and lead to weight loss.

Intermittent fasting leads to higher Human Growth Hormone (HGH) levels which lead to enhanced tissue repair and healing. IF can normalize insulin sensitivity which can ward off insulin resistance (type 2 diabetes). IF can lead to less binge eating by normalizing the hunger hormone ghrelin. IF can reduce inflammation and free radical damage.

The benefits of IF are null and void if the foods you normally eat are high-glycemic, highly processed foods found in the typical American diet. In order to gain the benefits of IF, your food choices need to be towards the fiber-rich, anti-inflammatory Mediterranean diet with lots of multi-colored vegetables, fruits, beans, nuts, seeds, whole non-processed grains.

Exercise can work in conjunction with intermittent fasting to improve your health and weight loss. You have to plan ahead to make sure that you don’t run out of energy for your workout, or worse, become light-headed. When initiating IF and exercise, make sure you have a banana or apple, a handful of almonds, and water close at hand. Exercise is recommended first thing in the morning and can be aided by eating enough low glycemic carbohydrates the night before (like black beans and quinoa with avocado salsa). After a workout, a low-fat protein-rich snack, for example, a smoothie with protein powder, should be eaten to make sure that any muscle breakdown gets replaced.

Caveats include that glucose is the only fuel that brain cells normally use. If you begin to feel brain-fog, it may be due to hypoglycemia which could benefit from eating a piece of fruit or carrots with hummus. The benefits of fasting will be lost if you eat large portions of highly processed, high-fat foods afterward.

Dr. Bren Boston is our Director of Pain Management and Sports Medicine, you can schedule an appointment with her by emailing us at, or calling 310-451-8880