*Disclaimer: This is not meant to be an exhaustive analysis of all the facets of this diet. It is an overview focusing on lifestyle changes required. As with any diet change, we strongly recommend you speak to qualified professionals, including your doctor, regarding your health and wellness.
Intermittent fasting is less about what you eat and more about when you eat. There is some variability on the timeline for fasting versus eating but most plans call for 16-18 hours of fasting and 6-8 hours of eating. This fasting period can put your body into a fat burning mode (you have to get the energy from somewhere).
The basic principle is that you eat your last meal in the evening (6-8pm) and then don’t eat again until the afternoon. This puts a big chunk of your fasting time during your standard sleep schedule (you did establish a standard sleep schedule before messing with your nutrition right? If not start here!) Because you are not taking in nutrients for such a long period of time your body needs to get energy from somewhere else, this is usually fat, although if done incorrectly it can also cannibalize muscle for energy.
The whole process takes advantage of a natural cycle built into our metabolism, namely that you usually go 8-10 hours without food as you sleep anyway. Most of us don’t wake up at 2 am starving. If you do, intermittent fasting is NOT a good place to start.
This is not a good idea with people who have serious struggles with food, people who are working out especially hard or often, people with poor sleep patterns, or people whose schedules might not allow them to consume large amounts of food (2000-3000 calories) in a 6-8 hour window.
This narrow window can make social interactions with others more difficult. It is hard to meet someone for breakfast/lunch of you are not going to eat because it is outside your window. This can also be difficult if you have a partner or children as well, your eating pattern will most likely never sync up with theirs very will and this can certainly cause tension.
You also need to plan what you are eating very closely to make sure you get all of the calories inside your window. You do not want to try and combine this plan with calorie restriction as well. Not getting enough nutrients can make that fasting time near unbearable and you actually might end up disrupting sleep because of hunger.
This is an interesting plan to try if you have ALL of the other variable dialed in. It is absolutely not a great first step. If you are unsure if you have everything else in good order, talk to a professional.