What is Intermittent Fasting and How Does it Work?

2 day meals_intermittent fasting

Article at a Glance

  • What is Intermittent Fasting and What are the Benefits?
  • How to Start a Fast
  • How Long Should I Fast?
  • How to Break A Fast
  • What Should I Consume While Fasting?
  • Should I Workout While Fasting?
  • Intermittent Fasting for Men vs. Women

What is Intermittent Fasting and what are the benefits?

Intermittent fasting or in other words, abstaining from food for a prolonged period of time. Intermittent fasting is different from just fasting alone as the name suggests – intermittent fasting focuses on consuming your calories within a specific window of time. In other words it is an extended period of time in which you are not eating or fasting. The benefits include physicial benefits such as fat loss while maintaining muscle tone and vascular functions which main include hair, nails and other more specific benefits due to the nutrient update that occurs. 

When you go into an extended period of time without eating, your brain goes into survival mode. This may seem counterintuitive, but it actually has mental health benefits. When your brain goes into this mode, you are actually able to focus while your body creates ketone bodies. You may have heard of ketones with the growing trend in the keto diet. Your body produces ketones, which are tremendous brain fuel. Intermittent fasting and the keto diet are, however, two different things. 

On top of the mental benefits, there are cellular benefits or overall health benefits through autophagy. Autophagy is the body’s natural recycling process of old and damaged cells. This process consolidates the cells into stronger, more powerful, efficient cells. This process can make your skin glow better, make you live longer and improve organ function. 

How to start an intermittent fast

The actual process of starting a fast is incredibly simple. What you eat leading into a fast though can make a big difference. 

Fat, Fiber and Protein are Essential to Reaping the Benefits of Intermittent Fasting – If you consume a higher fiber food, you will feel more satiated. Consuming a higher fiber and protein food such as a Real Food Bar prior to starting a fast will help you push through your fast. A higher fat food will also help as it will digest slower and leak free fatty acids into your blood stream more so that you are able to produce ketone bodies. You won’t get the stomach growls, while getting the same metabolic effects. Real Food Bar provides a good balance of fiber, fat and protein without being a heavy meal which makes for a great option as a food to consume prior to intermittent fasting. 

Real Food Bar Variety Pack

How long should I fast?

When you are fasting, the benefit you are trying to achieve is usually dictated by how long your fast is. What this means is the shorter the fast, you are able to reach body composition effects while the longer the fast, you are able to tap more into the cellular rejuvenation effects. 

One place to start is with a 16 hour intermittent fast, also known as 16×8 fasting. What does this mean? Fasting for 16 hours followed by an 8 hour eating window. The 8-hour window doesn’t necessarily mean that you are eating for the full 8 hours. This might mean a 4 hour window of eating instead. 

16 hours is generally the fasting window to start due to the benefits accompanied by it. You can work your way up to an 18-20 hour fast. 

This might include stop eating by 10pm, waking up and not eating again until 2pm. 

What to consume while intermittent fasting

You can consume black coffee. Coffee can be very powerful. The Polyphenols in coffee can actually encourage autophagy. Cherries are also a great source of polyphenols (see our Cherry Cashew bars). Caffeine and support a fast, autophagy including cellular rejuvenation. Tea has similar effects. What about Bulletproof coffees or creamers? In a fast, you should keep all calories out. It should simply be basic black coffee or tea. What about diet sodas? Diet sodas are a little bit more of a gray area. However, since they consume artificial sugars, they can still trigger an insulin spike. The insulin spike in sweeteners like stevia, sugar alcohol or ethyritol can screw up your fast because it triggers a metabolic response. If you are going to consume a form of added sugar, it is recommended to consume stevia or honey as they are natural sweeteners. Artificial sweeteners will trigger an excitotoxin response in the brain. 

How about bone broth? Generally speaking, bone broth should not be consumed in intermittent fasting (there are specific fasts that do call for bone broth). 

What about preworkout powders such as branch chained amino acids? This is not recommended. BCAAs can actually break your fast. When your in a fasted state, your physiology is working to your advantage and will preserve muscle. 

Check out this easy calculator to quick start your intermittent fasting journey by Fitness Volt

Methods of Intermittent Fasting

There are many different ways to implement an intermittent fast but we’ve provided a select few options from our calculator which include…

  • 16/8 method (fast for 16 hours and feed for 8)
  • 14/10 (fast for 14 hours and feed for 10)

OMAD (one meal a day)

  • OMAD (23:1)
  • OMAD (22:2)
  • OMAD (20:4)

Check out this quick start guide to intermittent fasting for beginners. 

How to break intermittent fasting?

There are several different methodologies here. 

Bone Broth – Consuming 4-6 oz. of bone broth is a great way to break a fast. It focuses on the organs including collagen. When you are in a fast, you may end of temporarily weakening the gut glucosal layer. This layer protects you from any type of acid or damage to the gut. The bone broth can actually help you absorb nutrients in the gut better and improve digestion. 

Don’t Eat Fats & Carbs After – Carbs cause an insulin spike. This causes the cells to be very receptive to whatever you eat. The carbs go into the cell and also the fats. If you consume just fats, it doesn’t cause an insulin spike in the same way that a combination of the two would. The ideal scenario is to consume carbs and protein or fats and protein. 

When should I workout?

If it’s your first time fasting or you are new to fasting, be sure to listen to your body and don’t feel pressure to workout during a fasted state. If you want more of a physiological response, you can workout during your fast. If you workout at the end of your fast, you do get the biggest benefit in terms of breaking down fat, but you may not have the best workout performance. Many people like to workout in the beginning of the day which could be the middle of the fast in order to get the benefit of sleep and energy still remaining from the night before. 

When you break your fast, all the blood is going into your vital organs to digest your food. If you workout immediately after breaking your fast, you may have performance benefits, but you may not be allowing your body the appropriate amount of time to digest your food; instead you are sending energy to your extremities to provide power for your workout.

According to the Journal of Physiology, when you workout in a fasted state, you burn significantly more fat than you would if you workout after breaking your fast.  

Men versus Women in Intermittent Fasting

We all know that men and women have very different metabolisms and different needs. Due to the complex reproductive systems in women, fasting can be more dangerous for women than men. Women need extra reserves in order to carry a child. Due to those unique needs, women’s bodies may go into a fighting response to fasting, sending higher hunger signals. When women experience insatiable hunger after undereating, they are actually experiencing the increased production of these hormones, leptin and ghrelin. It’s the female body’s way of protecting a potential fetus—even when a woman is not pregnant.

There are benefits to fasting for a short period of time so it may be worth starting at a shorter fasting time and working your way up.

Easing into intermittent fasting by starting with shorter fasting windows can help with initial symptoms of hunger and discomfort. But if it becomes too uncomfortable, be honest with yourself, accept it, and move on.

At the end of the day, nothing can have a greater impact on your health than a diet consisting of real, whole foods, and a lifestyle that prioritizes your physical, mental, and emotional well-being.