When you're fasting, you stop the supply of energy, but your body must burn energy to function. Our bodies have plenty of energy stores in the form of glycogens. The process our bodies use to burn this energy, called Glycolysis, lasts for the first 16-24 hours of fasting, after which our stores are completely depleted. After this period, the body must seek an alternate energy source — and you may have guessed it right: it comes from burning the stored fat.
The process that our bodies use to get energy from fat is called Ketosis. It is how ketone bodies, which come from fat, are converted to energy.
Another thing that happens when your body switches to ketosis is called Autophagy: the breaking down of senescent or aged cells. The accelerated renewal of cells is associated with health and longevity benefits.
You can read them in more detail to get behind the science and studies, but here's the gist: it helps to think of Intermittent Fasting as more than just a way to lose fat. Most intermittent fasters fast for long term benefits, and so should you!
The Circadian Rhythm Fast (13:11): Aim to start fasting as close to sunset as possible for at least 13 hours daily
(Recommended) 16-Hour Intermittent Fast aka Leangains (16:8): Popularized by Hugh Jackman and Dwayne "The Rock" Johnson. Start your fast after dinner (say 8 PM), and fast until lunch next day (say 12 PM).
The Warrior Diet (20:4): By trimming the eating window into an even shorter one (just 4 hours), you are trying to maximize the benefits of fasting by letting your body stay in fasted state even longer.
The Monk Fast (5:2): This constitutes two 36-hour fasts over the week. A typical schedule may look like:
Fast 1: Start Sunday evening after dinner (7 pm). End Tuesday morning when you get up (7 am).
Most likely, your fast will start right after an early dinner (around 6 pm), so the first thing you'll miss is light snacking some people indulge in before bed time.
When you get up in the morning — the only thing you'll be allowed to have is a cup of coffee/tea. If you're doing a 16 hour fast, you'll be at lunch in no time, and you can resume eating as normal.
But if you go beyond 16 hours, things start to get interesting. As your body depletes the glycogen stores in liver and shifts to ketosis (more on this in the next post), practitioners report getting a sensation of mental clarity (whatever that means — you'll have to try it to experience it), and an absence of hunger. You'll find that you're much more focussed at work, and may even feel a little colder than usual!
Remember: drink plenty of water. A lot of water that our body needs comes from the food we eat. In the absence of that, it's critical that you drink a lot more water than you are used to drinking. Not doing so will result in headaches. Also, I recommend adding i...
That's the whole point. But here's the good part: you can, and should drink anything that's non-caloric. This includes:
Unsweetened black coffee
You get the idea: as long as it has 0 calories, you can drink it. This also includes artificially sweetened drinks like Vitamin Zero water etc that contain electrolytes. I don't really like artificial sweeteners though since they have their own downsides, including interfering with fat loss (aspartame), but they're not a deal breaker.
Caffeine also serves as a mild appetite suppressant. It is common to feel hunger pangs, but this happens since you're in a habit of eating every few hours. As your body adapts to your fasting ...