For many people, the very word “fasting” conjures up visions of days on end spent hungry, grumpy, tired, and...did we say hungry? If the idea of going without food for any amount of time has you frantically in search of your next meal, it’s time for a refresher on the very real benefits of fasting and just how easy it is to fit the modern version of this eating “siesta” into your everyday life. You see, although fasting—going without food for a determined amount of time—has been popular for centuries as both a way to support health and as an important component of religious and spiritual traditions, the strict (and long) fasts of yesteryear were often unrealistic for people who couldn’t take a week off work or attend a retreat for a safe fasting experience.
Let’s take a look at the four major benefits of intermittent fasting for your health and wellness.
Weight Loss and Healthy Metabolism
It may seem obvious that fasting can be a great way to lose weight; after all, you are eating less calories, which usually helps you shed pounds (except when it doesn’t, like with impaired nutrient absorption). But, the benefits of intermittent fasting for weight loss are actually due to much more than just a net loss of calories.
Giving your body significant breaks from eating (and we’re not talking about the four hours between lunch and dinner) can optimize your hormone function, facilitating weight loss and supporting a healthy metabolism. In one study, mice who fasted for 15-16 hours each day lost 12% of their body weight. (1)
How does it work? Well, there are several different mechanisms at play, but fasting increases levels of human growth hormone (HGH), a hormone that increases muscle mass and ramps up your metabolism—a one-two punch for weight loss. In a research trial, fasting increased HGH levels in women by 1,300% (2,000% in men)! (2)
Fasting also supports healthy insulin responses, which can keep your metabolism in check. What’s more, as your body runs through its primary source of energy (glycogen) after several hours of fasting, it switches to burning fat for fuel.
Better Mood and Cognitive Function
It’s no wonder that fasting has been associated with spiritual traditions for hundreds of years—research proves that going without food can support mood and brain function.
Studies show that intermittent fasting increases production of brain-derived neurotrophic factor (BDNF), a protein that fertilizes brain cells, encourages neuron growth, and builds and maintains brain circuits. (3) The result? Better memory, brain function, and yes...even a happier mood.
In one study, researchers found that mice on an intermittent fasting schedule for 11 months showed improved brain structure and function. (4) In another trial, men who fasted experienced significant decreases in anger, tension, confusion, and other mood disturbances, as well as reduced weight and body fat percentage. (5)
A Longer Life
Given the choice, most of us would welcome the opportunity to live a longer, healthier life—the good news is that intermittent fasting may be a key ingredient in your long-life recipe.
Chronic calorie restriction (undernutrition without malnutrition) has long been associated with an increased lifespan in various animals, fish, and even worms, but scientists are now discovering that fasting has the same—if not better—results when it comes to longevity. (6)
Besides its beneficial effects on everything from blood sugar and healthy metabolic response to heart health and cholesterol levels, it turns out that intermittent fasting induces a sort of mild “stress” that encourages cells to ramp up their defenses, while also enhancing their stress-coping abilities.
During fasting, our cells initiate a process of waste removal and cellular repair that rids the body of molecules that are damaged or not functioning properly. (7) This increased detoxification can keep you healthier, longer.
Support Gut Health
As with every aspect of our health, the conversation wouldn’t be complete without exploring our amazing microbiome, the collection of trillions of bacteria living in and on our body. The beneficial bacteria in our gut help support everything from our immune system and digestion to our moods and memory.
In fact, without the good guys in our digestive tract, we’d be hard pressed to maintain any sort of health or vitality.
Luckily, intermittent fasting gives your hard-working gut microbes a break from their digestion duties, so they can focus on cleaning house and keeping their populations intact. Fasting can also increase the diversity of your gut bacteria—important for your immune and overall health—and aid in your body’s resistance to bad guy bacteria. (8)
In addition, researchers are discovering that daily fasting activates a gene that strengthens the gut barrier, which protects us from harmful microbes, toxins, and other substances that can leak into the bloodstream and trigger immune reactions. (9)
3 Easy Intermittent Fasting Methods
So you know some of the amazing benefits of intermittent fasting; now, how do you go about implementing a non-eating regimen? There are many different ways to incorporate intermittent fasting into your lifestyle; here are the most popular, and the easiest to stick with for the long-term.
• The 16/8 method (also called Leangains): Once you get into a routine, the 16/8 method is arguably the simplest intermittent fasting protocol because a good portion of your fasting time is while you sleep!
- Here’s how it works: You divide your day into a non-eating period (14 hours for women, 16 hours for men) and an eating period (10 hours for women, 8 hours for men). During your non-eating period, you consume nothing but non-caloric beverages like coffee and water, and during your eating period you can eat as much (healthy) food as you want! The easiest way to implement the 16/8 plan is fasting from dinner until a late breakfast or early lunch the next day, such as from 7:00p.m. on Monday until 9:00a.m. on Tuesday (7:00pm-11:00am for men), and continuing this every day.
• The 5:2 diet (also called the Fast Diet): While on the 5:2 plan, you’ll eat normally five days of the week and drastically reduce calories on two days of the week.
- Here’s how it works: Not a true fast (but still considered intermittent fasting), the 5:2 plan has you limiting your intake on any two days of the week to 500-600 calories. You get to choose the days, but it’s important to carefully plan out your calories on your restricted days to get the most nutritious bang for your buck. On the other five days, you’ll just follow your normal eating plan.
• Eat Stop Eat: This method has you following a 24-hour fast, 1-2 times per week.
- Here’s how it works: You’ll fast—only consuming non-caloric beverages—for a full 24 hours, either one or two days every week. For example, you can fast from dinner on Monday to dinner on Tuesday or from lunch to lunch or breakfast to breakfast. On your non-fasting days, you’ll eat as normal. Some people find it hard to fast for a full 24 hours right off the bat, so you can work up to this amount by increasing your time each week.
As humans, we evolved not knowing where our next meal was coming from, and our bodies adapted to be able to survive—and actually thrive—during times of low or no nutrition. Some even argue that we are not meant to eat three square meals a day (every. single. day.) and that our bodies and minds function best when our diet mirrors that of our ancestors in quantity, quality, and timing.
Intermittent fasting allows us to eat more in line with how our body is designed to function, but it’s important to remember that what you eat is just as essential. Focusing on a whole-food diet packed with nutrient-dense fruits and vegetables and taking steps to support your overall gut health are perfect complements to an intermittent fasting plan. So, go for it! You have nothing to lose (except a little weight!) and in fact, you may learn that spending less time eating frees you up to discover the most healthy, happy version of you.
1. Cell Metab. 2014; 20(6):991-1005 [PMID: 25470547]
2. Intermountain Medical Center. (2011, May 20). Routine periodic fasting is good for your health, and your heart, study suggests. ScienceDaily. Retrieved January 18, 2023
3. Annu Rev Nutr. 2005; 25:237-60 [PMID: 16011467]
4. PLoS One. 2013; 8(6):e66069 [PMID: 23755298]
5. J Nutr Health Aging. 2013; 17(8):674-80 [PMID: 24097021]
6. Cell Metab. 2014; 19(2):181-92 [PMID: 24440038]
7. Autophagy. 2010; 6(6):702-10 [PMID: 20534972]
8. Cell Metab. 2014; 20(6):1006-17 [PMID: 25470548]
9. Proc Natl Acad Sci U S A. 2016; 113(23):E3307-14 [PMID: 27208292]
*These statements have not been evaluated by the Food and Drug (FDA) Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.