Another big concern of mine, but it turns out this fear was unfounded. We’ve been told by the supplement industry that we need to consume 30 g of protein every few hours, as that’s the most amount of protein our body can process at a time. Along with that, we’ve been told that if we don’t eat protein every few hours, our body’s muscle will start to break down to be burned as energy.

The problem is that we tend to spend so much time in the fed state, fueling our bodies exclusively with glucose, that we become addicted. Once the flow of glucose stops and our insulin levels drop, we start getting hunger pains. This is one of the reasons that overweight individuals — people with more than adequate energy stores in their fat cells — often have such a difficult time cutting back on food intake. They’re not starving, but they’re not getting the glucose their bodies are used to.

How It Works: Warriors-in-training can expect to fast for about 20 hours every day and eat one large meal every night. What you eat and when you eat it within that large meal is also key to this method. The philosophy here is based on feeding the body the nutrients it needs in sync with circadian rhythms and that our species are “nocturnal eaters, inherently programmed for night eating.”

Hi Tade, there are benefits and pitfall in training in a fasted state. Though fasted training may push your workout routine to the next level, always listen to your body to make sure it’s not suffering. If you’re used to high-intensity workouts, fasted training might not be for you. For more info, you can check out this link:
IF as a weight loss approach has been around in various forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code. IF generated a steady positive buzz as anecdotes of its effectiveness proliferated.
I’ll share some of my experiences, now doing heavy strength training for 3 years in a fasted state: For my first “fasted” workout or two after starting an IF protocol, it was very weird to not eat before training. However, after a few sessions, I learned that my body could certainly function (and even thrive) during my training sessions despite not eating a pre-workout meal.

People fast for so many reasons; some fast because they're trying to lose weight while others fast to improve medical conditions such as diabetes and high blood pressure. The science behind intermittent fasting has slowly been piling up, too, with research showing that participants of intermittent fasting experience a reduction in weight and inflammation and improvement in insulin sensitivities.

I don’t recommend that you go straight for a 1-2 day fast, but begin by restricting yourself to certain eating windows. Typically people restrict themselves to the hours of 5pm – 11pm. People often refer to their fasting windows by numbers: 19/5 or 21/3, for example, means 19 hours of fasting and 5 hours eating or 21 hours fasting and 3 hours eating, respectively.
On the flip side of that, eating keto can make your periods of fasting more manageable. For example, someone who is eating a diet higher in carbs will likely have more discomfort with intermittent fasting as the body constantly switches between glucose for fuel and ketones for fuel. By continuing to eat keto even during feeding periods, you can keep your body constantly running on ketones.
Whichever option you choose, there's enough evidence to show that intermittent fasting has many health benefits. Dr. Palanisamy sums it up best by saying, "The final caveat is that some fasting is better than none. So if having a regular or even bulletproof coffee is the only way that you can stick with the practice of intermittent fasting, then it's probably worth it."

A 2018 review of intermittent fasting in obese people showed that reducing calorie intake one to six days per week over at least 12 weeks was effective for reducing body weight on an average of 7 kilograms (15 lb); the results were not different from a simple calorie restricted diet, and the clinical trials reviewed were run mostly on middle-aged women from the US and the UK, limiting interpretation of the results.[25] Intermittent fasting has not been studied in children, the elderly, or underweight people, and could be harmful in these populations.[25][26]

There were [no statistical] differences between the low- and high- [meal frequency] groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing meal frequency does not promote greater body weight loss under the conditions described in the present study.