The Basics
To begin, let's breakdown this phrase into its two parts: intermittent and fasting. Textbook definitions describe "intermittent" as a pattern in which one stops or ceases for a certain amount of time, whereas "fasting" is simply abstaining from food. Therefore, intermittent fasting is abstaining from food for a certain amount of time. The usual fasting periods operate on a 16/8 schedule where an individual will fast for 16 hours and eat in an 8 hour time window. Though this may seem like forced torture, but the theories behind this fitness trend carry weight.
The Reasoning
Before you run for the hills when you hear that you can only eat in an 8 hour window during intermittent fasting, listen to some of the research that's been done on it. The main goal of intermittent fasting (or IF) is to make an individual more aware of the food they are putting inside their bodies. Instead of eating breakfast every morning because it's just "what you do", IF places a larger emphasis on the food itself. If you only have eight hours to get in enough food to fuel your body, the theory is that you will be more conscience of what you are eating. In addition, by limiting the hours of eating, an individual will be less likely to succumb to temptations such as midnight snacking, leading to weight loss due to a caloric deficit. As for actual biological differences, IF has been found to increase human growth hormone (which helps shred fat), decrease insulin levels, and improve the functionality of the cells in the human body. IF is also a good way to decrease fat while holding onto muscle, as a study demonstrated that IF creates less of a muscle deficit than a traditional calorie deficit diet. Overall, research seems to suggest that if you're looking to get lean and mean, without succumbing to a fixed food diet, IF could be for you.
Conclusion
Intermittent fasting has caught the attention of many fitness models, celebrities, and social media personalities alike, but there are a few things you should keep in mind before diving in headfirst. Remember that IF is not for everyone-if you're someone who hates going without breakfast or prefers a late dinner, it may be harder to set a schedule. And that's okay, the whole point of IF is supplying a tool to help you reach your own fitness goals. A final tip is to keep in mind that everyone's goals are unique and so are their steps to reaching it, so even if IF doesn't work for you, it doesn't mean you've "failed"-that's just your body's way of telling you there's a better tool out there for you to use.