Updated date:

Is Intermittent Fasting Healthy?

Chris is a Project Manager who spent over 7 years researching and writing for health brands like LIVESTRONG and Jillian Michaels' Livewell.

Intermittent Fasting for Weight Loss

Intermittent Fasting for Weight Loss

What is Intermittent Fasting?

With proposed benefits such as weight loss, brain boosts, and even longer lifespans touted with following an intermittent fasting plan, it's no wonder the practice has exploded in popularity. But what exactly is intermittent fasting?

Intermittent fasting (IF), also known as intermittent energy restriction, though recently popular, has been around for quite some time. However, it was a well-received documentary by Dr. Michael Mosley called Eat Fast, Live Longer, as well as the book The Fast Diet that brought the practice back into a worldwide fitness trend.

The practice of IF involves cycling between periods of eating and fasting. Times vary widely, but generally involve 16 hours of fasting each day (often from dinner the night before to around lunch the next day) or less commonly, 24-hour fasts twice per week. However, pushing all eating into an 8-hour block, say from 7 AM to 3 PM, and fasting outside of that window, has also gained popularity. This time restriction option shows more significant benefits for reduced insulin sensitivity and a reduction in blood cholesterol, according to Monique Tello, MD, MPH from Harvard Health Publishing.

Why Do People Fast?

People fast for a multitude of reasons, from health concerns and weight loss to religious acts. However, intermittent fasting is used mainly for weight loss, with potential secondary benefits on blood sugar, cholesterol, and brain function.

The primary benefit of intermittent fasting is burning fat. When you allow enough time between meals, your insulin levels drop. Insulin is a key factor in taking the sugars digested from meals and storing the energy from them as fat once your cells have used up whatever they can directly. When insulin levels drop, and no new energy sources are introduced to the body, the body is able to then release fat to be used as energy. When insulin levels drop low enough for long enough during fasting, your body targets stored fat to burn for energy resulting in weight loss.

Intermittent fasting may have secondary benefits as well, though more research is needed to determine just how connected these benefits are to the practice. Secondary benefits include improving the process of cellular repair in your body and increasing the presence of Human Growth Hormone (HGH) in your bloodstream, which helps boost muscle growth. Fasting also improves gene expression to help protect against disease, lowers inflammation and oxidative stress, reduces risks for diabetes through improving insulin production and sensitivity, and lowers blood pressure and LDL cholesterol. The practice also initiates the growth of new nerve cells, which can boost brain performance.


Making Intermittent Fasting Easier

Your body is primed to survive, and a sudden change in the availability of food over parts of the day can cause your body to react as if food is not going to come. Feelings of starvation and hunger pains are typically not far behind, making the initial transition to fasting difficult. You're also battling against the body's natural circadian rhythm, expecting to eat during the day and sleep at night.

However, there are ways you can transition slowly into intermittent fasting, as well as methods of fasting that help mitigate the body's natural starvation reaction. First is easing into intermittent fasting with a few days a week. This slow transition allows time for the body to adjust to the new schedule. You may still feel hunger, but knowing there's respite between fasting sessions can help satisfy the concerns of your brain. Second is pushing all your meals into an 8 hour time period earlier in the day. Research performed by a team at the University of Alabama found that restricting meals to an early 8 hours period, in this case, 7:00 am to 3:00 pm, helped limit feelings of hunger while still providing the benefits of fasting.

Potential Risks of Fasting

While intermittent fasting has a long list of potential benefits, the practice is not without its risks. The most critical risk to keep in mind is for those that struggle with other food-related issues, such as eating disorders, as fasting may trigger side effects for those struggling with food in other areas. You should also talk to your doctor before starting a fasting program, especially if you have other underlying health issues or diseases. Those with more advanced cases of diabetes, or who are undergoing treatment with medication for diabetes generally should not use intermittent fasting unless directed and supervised by a doctor. Women who are pregnant or trying to become pregnant should also avoid fasting, as well as women who are currently breastfeeding.

This content is for informational purposes only and does not substitute for formal and individualized diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed medical professional. Do not stop or alter your current course of treatment. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2020 Chris Sherwood