Intermittent fasting [1] (IF) has been getting tons of attention lately, since so many people have tried it and found success when trying to lose weight [2]. IF is an eating pattern characterised by a period of time when you don't eat (called your fasting window), and a period of time when you do eat (your eating window).
What is 5:2?
There are many different methods of intermittent fasting [3], and one popular one is known as the 5:2 plan or the Fast Diet. Made popular by journalist and doctor Michael Mosley [4], twice a week (on nonconsecutive days) you restrict calories to around 500 a day (600 for men), and for the other five days you eat normally, but not as if you are on a diet. On fasting days, you can eat three times a day, but your meals will be tiny. It may be better to eat one or two meals instead, so you feel more satisfied.
This form of IF can help you lose body fat and inches because it ensures a calorie deficit over the course of the week. If you normally eat 1,600 calories a day, you're now cutting out 2,200 total calories. People on the 5:2 plan tend to lose about half a pound to a few pounds a week [5], depending on how much weight they need to lose.
Pros
This plan is flexible, with no restrictions on what you can eat on regular days (within reason), and you can choose which days to fast based on your schedule. If you know you have a party, work dinner, or school function on certain days, you can choose the other days to fast, and you can even vary the days from week to week. Some people may prefer this plan since you only having to restrict and monitor your diet twice a week, and you can enjoy the foods you love on the other days. This is what makes the 5:2 plan sustainable for your entire life.
Weight loss is just one benefit to intermittent fasting [6]. You'll also experience better digestion, reduced bloating, reduced sugar cravings, higher energy levels, better sleep, and autophagy, where your cells have a chance to repair damage that can otherwise lead to diseases like cancer.
Cons
The one tough thing about this plan is that because it's not consistent, and you're not fasting every day [7], so you may feel more hungry on your fasting days. Also, 500 calories a day is not much at all, especially when you're used to eating 1,600 to 2,000 (or more!). So those days can be really tough, especially if you work, exercise, or have a family (preparing food for your kids is way too tempting!). Also, insane hunger the day after a fasting day can cause you to overeat, which won't help you lose weight.
If you're interested in intermittent fasting [9], consult with your doctor first, do your research, and figure out a plan that will work with your schedule and your lifestyle. The 5:2 plan might make the most sense and could be a good introduction to intermittent fasting.