If you’ve been paying attention to the big diets and health trends of the past few years, intermittent fasting has likely caught your eye at one point or another, and you’ve probably heard about the various forms of it—one of the most popular being intermittent fasting 16/8, or when you fast for 16 hours and eat during an eight-hour window.
While intermittent fasting, or IF, has only recently hit peak popularity, it actually mimics the prehistoric way of eating. Its rise can be attributed in part to celebrities like Jennifer Aniston and sharing her 16/8 intermittent fasting routine, with her “Morning Show” co-star Reese Witherspoon following a modified version allowing for some green juice in the morning.
As for why you’d choose to follow intermittent fasting, Nicole Grant, R.D., C.N.S.C., a registered dietitian at Zero, notes that a huge misconception is that it’s only about losing weight. “There are so many other positive outcomes from intermittent fasting that can be experienced including boosted energy, reduced inflammation, accelerated cellular repair, improved body composition, and it can even be an effective tool to mitigate risk for metabolic syndrome,” she notes.
The longer you fast, the more stages your body goes through—think moving from digestion, to fat burning to ketogenic—meaning that one cycle of eating may not work for everyone depending on specific goals and lifestyle factors. If you’re wondering how the 16/8 plan is different from other types of intermittent fasting and if it can work for you, read on to find out how it works and what you can eat on the 16/8 intermittent fasting plan.
What is 16/8 intermittent fasting?
Unless you’re doing a form of intermittent fasting that has you cycling through 24-48 hour fasting periods, following an eating cycle of 16/8 is possible. This simply means fast for 16 hours of the day and eat all of your meals within the consecutive 8-hour portion of the day. In order to be the most successful at intermittent fasting, you need to choose a cycle that works for you. There is some flexibility allowed in terms of which 8 hours you choose to eat during the day. Many experts recommend that you ease into intermittent fasting; for example, beginning by eliminating snacking after dinner and not eating again until breakfast is a simple way to start.
How often should you do 16/8 intermittent fasting?
You can do 16/8 intermittent fasting as often as you want—but it may be smart to ease in. “Ease your way into fasting to keep it sustainable,” encourages Lindsay Wandzilak, NASM celebrity trainer, nutritionist and founder of The Daily. “Pushing the hours to a crazy, uncomfortable place can lead to deprivation, binging, and guilt.”
Starting slow and increasing your fast by intervals every few days (or weeks, depending on how you’re feeling) can make it easier for your body and mind to adjust to a new eating window (especially if you are a habitual late-night snacker). If you approach intermittent fasting as a lifestyle shift, you are more likely to find success sticking to the fasting schedule on a daily basis.
Related: What Studies Say About Intermittent Fasting
What to eat during intermittent fasting 16/8
Though intermittent fasting isn’t a diet in the sense that there are food-specific restrictions imposed, it is recommended that you eat as many whole foods as possible and avoid processed foods. “The quality and nutritional value of food matters greatly when practicing any kind of health plan,” advises Wandzilak.
According to Grant, what you choose to eat will depend on your goals. When doing any type of fast, water is the most common beverage to consume during your fasting period. However, if you’re looking for a lifestyle reboot—or if your goal is weight loss—coffee or tea is acceptable during fasting periods as well.
Related: Check Out These Intermittent Fasting Results
“If gut rest is your ultimate goal with fasting, then no food or beverages, aside from water, should be consumed during a fast,” explains Grant. “However, if longevity, weight loss or metabolic benefits are your goal, then sometimes a few calories, such as plain coffee or tea, can be consumed during your fasting period without having much of a negative impact on the outcomes.”
Most experts agree that standard diet recommendations are also encouraged when intermittent fasting, though Grant specifies that prioritizing protein during your first meal of the day can help your body as it rebuilds and repairs as it prepares to once again enter the digestion phase.
Best hours for intermittent fasting 16/8
When choosing which 8 hours of the day will make up your eating window, really considering your daily routine and schedule will be key. Most often, people following 16/8 intermittent fasting will choose to skip breakfast and eat in a window from roughly 11 a.m.-7 p.m. or 12 p.m.- 8 p.m., with those later hours allowing for flexibility for after work get-togethers and later dinners with friends and family—this option is also great for late-risers. If you choose to allow for coffee or tea in your plan, you can ease into your day with a cup and then begin your eating window with lunch or a late-morning snack.
In our current pandemic climate, however, you probably don’t have any after-work gatherings with friends on your agenda—in which case you may want to try moving your last meal earlier in the day so you can allow for an earlier breakfast. Intermittent fasting allows for flexibility, and the best schedule can only be determined by what you will be able to stick with (and enjoy).
Related: What is Intermittent Fasting for Weight Loss?
Intermittent fasting 16/8 risks
As with any diet plan, you should begin by consulting your doctor. Grant specifies that everyone’s body responds differently to intermittent fasting—”due to genetics, current health, pre-existing conditions, and lifestyle”—and isn’t recommended if “you have Type 1 diabetes, are pregnant or have a history of disordered eating.” Speaking to your doctor and consulting a nutritionist or dietitian is beneficial if you are unsure of how to approach intermittent fasting or are looking for guidance personalized to your lab work and specific goals.
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Related: Is Intermittent Fasting Safe for Women?
It is important to know that researchers admit further research is needed in specific areas of intermittent fasting. For example, most research has been performed on overweight and middle-aged adults. Additionally, some research disputes that intermittent fasting is an effective eating method for those whose goal is losing weight. This study, however, was conducted in overweight and obese adults, further proving the need for studies to be conducted on people whose weight falls in the “healthy” range. With this in mind, it’s important to work with your doctor is the key to understanding if intermittent fasting will work for you and your specific goals.
Next up, follow these expert tips to successfully follow intermittent fasting.