What is intermittent fasting?
Intermittent fasting isn't just a way to lose weight — it can come with some other health benefits.
It’s not a diet. It's a timed approach to eating.
Intermittent fasting, otherwise known as IF, involves cycling between periods of eating and fasting. “Intermittent fasting is an umbrella term that is used to describe different ways to limit calories within the day or within the week to a certain timeframe.”, Dr. Felicia Steger from The University of Alabama at Birmingham tells Brut.
According to studies, Americans eat between 12 to 15 hours a day
Intermittent fasting doesn’t change what you eat, it changes when you eat, allowing your body to use its stored energy. “People may eat within an hour or two of waking up and then are really eating, you know, 12 to 15 hours over the course of the day. So really all waking hours, the body is busy really processing those calories, processing that energy. On time, restricted feeding really just gives our body more of a break during the day to be able to kind of rest and recover and work on some of those things outside of actual processing those calories.”, she continues.
The most popular variations
Most popular variations of IF are the 16:8 diet which restricts the daily eating window to 8-10 hours, and the 5:2 diet, which requires fasting on 2 nonconsecutive days a week. “Really there's some debate about that. And it all depends on, you know, the total number of calories that someone's eating in a day and how much exercise somebody is doing. But typically, the definition is really to limit calories to 8 or 10 hours during the day to really see some of that enhanced effect of the longer fasting period.”, she explains.
Losing weight and fighting chronic diseases
While most people try intermittent fasting to help lose weight, researchers suggest that fasting may increase longevity by lowering the risk for chronic diseases. “Yes, intermittent fasting can lead to a drop in body weight. But really, we even when we are controlling for body weight and we're keeping people at the same weight, we see improvements in insulin sensitivity, beta cell responsiveness, so really how quickly the pancreas is responding to blood sugar in the system. And we're seeing improvements in general the cardiometabolic health, blood pressure and all of those things.”, Dr. Steger states. Research with animals also shows that fasting may reduce cancer risk and slow one's aging. But intermittent fasting might not be for everyone, especially if you suffer from anxiety or a eating disorder.
While intermittent fasting has become a trendy lifestyle practice in a 24/7 food culture, it's been a practice throughout human evolution
“Fasting has actually been used for religious purposes, you know, for centuries. So there are groups of people that have used fasting for a number of reasons for a long period of time, and people have been able to do that. I think that the appeal is that we know people struggle in general to change what they're eating and we've been working on that for a long time in the nutrition world, but being able to give somebody a very quick, you know, easy way to see some of those metabolic changes, not necessarily teaching people what to eat, how to cook, how to prepare that and really changing their lifestyle as a whole.”, Dr. Steger concludes.