Fasting is a very common universal practice. Almost every religion observes some form a fasting or self-denial for spiritual practice and for inner awakening. There’s varieties of different fasting forms, but is fasting healthy? We’re going to explore the truths and lies about intermittent fasting, and whether or not it’s a weight loss and muscle building practice that’s worth starving over.
What is intermittent fasting?
Intermittent fasting is not a diet, you don’t restrict consumption of any food groups. The focus isn’t so much on WHAT you eat, rather the focus is on WHEN you eat.
It’s gaining momentum in popularity because you can eat whatever you want, but the catch is you have to do it in a certain pattern. Intermittent fasting is abstaining from meals in a day. So basically skipping breakfast is a form of intermittent fasting, and binge eating one day and then choosing to skip meals the next is considered intermittent fasting. But there are some intermittent fasting patterns that have been outlined by dietitians and nutritionist. Here are the 6 most popular intermittent fasting techniques :
- 5:2 method
Eat regularly for 5 days of the week then restrict diet to 500-600 calories or eat only 25% of normal daily calories for 2 days of the week
- 16/8 method
Fast for 16 hours of the day, then try to get 2-3 meals in a window of 8 hours.
Do a 24 hour fast once or twice a week. Finish dinner one day and then don’t eat until dinner time the following day.
- Spontaneous Meal Skipping
Eat only when hungry. It’s okay to skip meals from time to time if you’re not hungry.
- Alternate Day Fasting
Restrict calorie consumption every other day. Can either be no caloric consumption or reduced to 500-600 calories.
- Warrior Diet
Restrict calorie consumption to only fruits and vegetables throughout the day, and then have a huge meal in the evening. Also known as the one meal a day method.
Regardless of which method is used, intermittent fasting comes with mixed opinions on whether or not it’s a healthy form of consumption. Especially because many believe 6 small meals a day is the way to go when it comes to maintaining the body at peak metabolic rate.
So let’s evaluate the common truths and lies about intermittent fasting
1.) Your body will go into starvation mode with intermittent fasting.
This is a common lie about intermittent fasting. You will be hungry, that’s a certainty, but physiologically you will not be starving. Unless you refrain from eating for over 72 hours. Then you’ll be hitting into starvation mode. 
The most extreme intermittent fasting method has a 24 hour consumption restriction, but most, including the religious fasting practices tend to go upwards of 16 hours of fasting. Research shows between 10-16 hours of fasting your metabolism increases as it begins to break down fat stores to supply energy levels. The nervous system sends norepinephrine to the fat cells to breakdown into fatty acids called ketones. Those are then released into the bloodstream and can be used for energy. This has been linked to improved cognitive function, memory and learning functionality, as well as protect the brain. 
There’s no coincidence many great intellects in history have engaged in fasting, including Mark Twain, Gandhi and Plato.
2.) Intermittent fasting results in binge eating
This is a common truth but also a common lie about intermittent fasting. There is a difference between undernutrition and malnutrition. Fasting doesn’t give the green light to eat junk foods on non-fasting days. There has to be a balance of eating sensibly and then engaging in self-discipline to refrain from food consumption for lengths of time.
Cells become stressed when fasting, which allows for increased arousal and alertness. This is often times referred to as the fight-or-flight response. On those non-fasting days, it’s in our human genetics to seek nutrition but there’s also an emotional response as well, which drives the want for junk food rather than nutrient dense foods. However, there is a study that has evidence that with less frequent meals cravings are diminished as well. But there’s also a number of counter evidence supporting the need for many smaller meals daily to stave off cravings. 
With intermittent fasting because of the caloric deficit on days where you fast, there’s still evidence showing weight loss even with overeating on non-fasting days. But again, it does depend on what kind of foods are being consumed on those days.
3.) You can build muscle and burn fat at the same time with intermittent fasting.
This is a lie. There’s very little research that supports the ability to build muscle and burn fat simultaneously. Though many companies market diet pills or supplements with the ability to do so. But intermittent fasting does have a little grey area when it comes to this. I’ll explain further, but before diving in you should know that both building muscle and burning fat are two different processes.
There’s that elusive goal of burning fat simultaneously while building muscle. In order to burn fat, your need to be in a state of catabolic metabolism, which basically is a fancy way of saying in a state of breaking down large molecules to release energy. Let’s refer to catabolic as cutting. To get your body into a catabolic state, you’ll need to have a caloric deficit so your stored body fat is used as energy. As mentioned above, fasting is a good way to reach that caloric deficit.
But on the other side of the spectrum, in order to build muscle, you need to be in a state of anabolic metabolism. Which is a state of building and combining molecules in order to store energy. Good way to remember anabolic is by adding. So in order to achieve muscle growth you need a surplus in calories so new muscle tissue can be created.
This going to get more complicated than Brad Pitt and Angelina Jolie’s relationship. When you fast you stimulate human growth hormones (HGH), which plays a vital role in muscular development. Yeah, we just entered into that grey area of intermittent fasting. But it also plays a part in burning fat. 
Is your head ready to explode yet?
Again, remember that building muscle and burning fat are two different processes. Anabolic vs Catabolic. And this is important because, if you’re looking to burn fat but MAINTAIN your muscle mass, intermittent fasting is a great method to employ. 
Though a common lie about intermittent fasting is your can burn fat and build muscle, the realism of intermittent fasting is you can decrease your body weight by burning fat, but still maintain your muscle mass for the most part. But if you’re looking for hypertrophy and overall muscle strength, short-term fasting might not be the best method to use.
4.) Intermittent Fasting is a good way to reset your body
This is true.
With all the information above, there has been loads of evidence pointing to the benefits of intermittent fasting benefiting overall metabolism. But there’s another common thread linking all these studies together and that is insulin levels. Insulin manages stimulation of fat formation through lipogenesis, and fat burning in reduced insulin levels called lipolysis.
Throughout my research, it was nearly impossible to avoid how fasting improved insulin resistance. Insulin resistance in a modern health concern. Doctors are linking it to the decreased physical activity combined with excessive food consumption, which leads to weight gain and other plethora of health concerns connected to it like hypertension, diabetes and other cardiovascular diseases.
Without healthy insulin maintenance, your body cannot regulate the levels of sugar in your bloodstream. Your insulin increase after meals because your blood sugar (glucose) level increases therefore your insulin increases.
Why is insulin important? It helps direct the glucose in your blood to your liver, muscles, and fat cells. So when your blood sugar goes down, so does your insulin. Which, by no surprise your insulin levels are at the lowest in the morning. Seeing that it has been hours since your last meal. 
Why is this important? Insulin does more than just direct your glucose levels, it also helps with protein synthesis, storing fat, and breaking down fat. So if there is overconsumption, there’s a steady state of increased insulin levels this leads to increased fat storage. I’m not talking about spikes in insulin because spikes are a natural and healthy response. That just means the pancreas is sensing glucose increase so insulin is secreted quickly to manage it. Insulin levels do eventually come down and having lengthy time in between meals allows for lipolysis, and that is ideal if you’re looking to improve your insulin sensitivity and increase your overall metabolism.  
With insulin working efficiently, this helps for improved weight loss and better overall body regulation. Moreover, through studying intermittent fasting on rats, there has been evidence to show that intermittent fasting helps with overall cellular aging and growth. Especially with methods like alternating day fasting.
With many diet, lifestyle or exercise trends there’s alway going to be common lies with kernels of truth associated with them. Intermittent fasting is a way of life that might not be beneficial to everyone. If someone gets increasingly irritable, moody or fatigued when hungry, intermittent fasting might not be a good option. And remember, there is no magic pill that creates immediate results. This is a method that requires a certain amount of commitment in order to achieve wanted results. Just like any program that alters body composition for improved living.
 Authority Nutrition: https://authoritynutrition.com/6-ways-to-do-intermittent-fasting/
 PLOS: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0102031
 National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680567/#!po=25.0000
 Legion Athletics: https://legionathletics.com/intermittent-fasting/
 Cambridge University Press: https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/psychology-of-food-craving/3BF21EC65DFE3A23A3590DB4CC557346
 A Workout Routine: http://www.aworkoutroutine.com/how-to-lose-fat-without-losing-muscle/
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 National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680567/#!po=25.0000
 Weightology: http://weightology.net/weightologyweekly/index.php/free-content/free-content/volume-1-issue-10-insulin-physical-activity-and-weight-regain/insulin-an-undeserved-bad-reputation-part-2/
Emily has spent the last 8 years comparing, reviewing and analyzing ingredients in the supplements industry. She has worked extensively with dieticians, nutritionists and personal trainers to separate fact from fiction and help people achieve their fitness goals. In her free time she works and enjoys the outdoors with her husband and 2 children.