Take a look at any fitness magazine, website, podcast or YouTube channel and you’re bound to find at least a feature or two on intermittent fasting. This eating method, not diet, has been linked to a plethora of health benefits from reducing diabetes risk to improving cell processes. It has also been hailed as a steller weight loss strategy, though it can also be employed successfully by individuals looking to gain or maintain their weight since it does not require a caloric deficit. So, what exactly is IF? What are the benefits and risks? And can implementing it in your diet help you reach your goals?
Intermittent fasting is a method of eating that involves abstaining from food for set periods of time. According to some studies– including one published in the Canadian Medical Association Journal by Roger Collier– this fasting allows the body to dip into its fat stores for energy. In fact, in a recent TED Talk on the subject, nurse practitioner and functional nutritionist Cynthia Thurlow described IF as “spring cleaning for the body.” Basically, abstaining from eating allows the cells to focus on other functions rather than constantly dealing with processing food.
There are many ways to practice IF, which serves as an umbrella term for the various beneficial fasting routines that are commonly practiced today. One of the most common is the 16:8 schedule, which involves a 16 hour fast and an 8 hour window of eating. For example, an individual practicing this routine might eat between 12 and 8 p.m., fasting until noon the next day. However, going this long without eating can be difficult for some people, so it is worth noting that the body can still reap benefits from a shorter fast.
A modified version of this method would be to only eat for 14 hours per day, while Medical News Daily suggests beginners could start with a fast as short as 12 hours. Other variations of IF include skipping meals at planned times or fasting for 20-24 hours one or two days per week.
The benefits of this routine are numerous. According to Kris Gunnars, a nutrition researcher for Healthline, practicing IF can reduce blood insulin levels, reduce stress and inflammation in the body and might even play a role in reducing cancer risk (though more research on this is needed). IF has also been linked to fat loss and improved body composition. For individuals looking to lose weight, this factor is crucial. According to Gunnars, “IF works on both sides of the calorie equation. It boosts your metabolic rate (increases calories out) and reduces the amount of food you eat (reduces calories in).”
This occurs for a few reasons: IF works to boost metabolic rate by lowering blood insulin levels, depleting glycogen stores and increasing growth hormone, resulting in increased burning of fat stores. In addition, many people who fast for weight loss will end up consuming less calories than they would have if they chose to eat all day long, as many who practice IF tend to cut down on meals.
However, intermittent fasting does not have to be synonymous with weight loss. If you’re looking to maintain or even gain weight, the key is to make sure you take in enough calories during the eating window. In fact, celebrity trainer Jillian Michaels stated on her self-titled podcast that IF should not be confused or mixed with caloric deprivation. She also said that individuals can still benefit from fasting without sticking to a strict schedule. For example, Michaels herself admits that while incorporating IF into her routine, she frequently gets hungry 13 hours into her fast and cannot abstain for the full 16 hours.
Though IF can be a great tool, it is not for everyone. According to the Center for Discovery, an organization that treats eating disorders, “Individuals who are underweight, struggling with weight gain, under 18 years of age, pregnant or who are breastfeeding should not attempt an intermittent fasting diet.” In addition, people with an otherwise unhealthy relationship with food who are likely to binge-eat during eating periods may also want to avoid IF. If you are unsure if this applies to you, speak with a doctor or nutritionist before trying intermittent fasting.
For individuals looking to try IF for the first time, remember Michaels’ advice to listen to your body. If you can make it through a 16-hour fast without feeling like crap, by all means go for it. Remember that you can always ease into this method of eating, trying it out with shorter casts and seeing what works for you.
Like with any diet or fitness regimen, nobody can be perfect 100% of the time, especially when something as simple as having a cocktail or meeting friends for brunch can break your fast early. However, a slip up or two does not negate the benefits. So, if you happen to grab a late night snack, don’t write off IF– you can always get back on track the next day.
Finally, remember to always stay hydrated. Drinking water won’t break your fast, and neither will tea or plain coffee (if you can stomach it.) And, of course, try to consume healthy and whole foods during eating periods. While IF helps your body to use fat stores as energy, you’ll probably have less fat to begin with if you cut down on the Twinkies and pizza.
If you are looking for an easy way to track your eating, try downloading an app to help. Many exist just for this purpose and can assist in tracking your meals and timing your fasts.