Of course, fasting — regardless of the method — isn’t for everyone. If you have any medical conditions or special dietary requirements, it’s smart to consult a doctor before giving intermittent fasting a shot. Anyone who tries it should also plan to be highly self-aware while fasting. If it’s not agreeing with you, or if you need to eat a little something to hold you over, that’s just fine. It takes our bodies time to adjust, and some require more than others. Keep in mind that hormones can make it harder for women to follow a fasting plan than for men. “Be cautious at first, and start slowly [with a shorter fast],” Shanks recommends. If it doesn’t make you feel better, try something different, or accept the fact that maybe fasting isn’t for you.
Intermittent fasting is hard in the contemplation, of that there is no doubt. “You go without food for 24 hours?” people would ask, incredulously when we explained what we were doing. “I could never do that.” But once started, it’s a snap. No worries about what and where to eat for one or two out of the three meals per day. It’s a great liberation. Your food expenditures plummet. And you’re not particularly hungry. … Although it’s tough to overcome the idea of going without food, once you begin the regimen, nothing could be easier.”
If you're worried you’ll be starving while fasting, you’ll be pleasantly surprised! Intermittent fasting decreases your hunger hormone ghrelin, which in turn can increase dopamine levels in the brain. (Just another example of the gut-brain axis at work.) Fasting can also help free people from emotional eating and kill cravings by transitioning your metabolism from unstable sugar-burning to steady fat-burning.
Pros: While 24 hours may seem like a long time to go without food, the good news is that this program is flexible. You don’t have to go all-or-nothing at the beginning. Go as long as you can without food the first day and gradually increase fasting phase over time to help your body adjust. Pilon suggests starting the fast when you are busy, and on a day where you have no eating obligations (like a work lunch or happy hour).
When you eat a meal, your body spends a few hours processing that food, burning what it can from what you just consumed. Because it has all of this readily-available, easy to burn energy (thanks to the food you ate), your body will choose to use that as energy rather than the fat you have stored. This is especially true if you just consumed carbohydrates/sugar, as your body prefers to burn sugar as energy before any other source.