As a health practice, fasting focuses more on when you eat, rather than exactly what you eat. Although "intermittent fasting" may seem like a food trend that has gained a lot of attention only recently, fasting in one form or another is a practice that's thousands of years old.
Fasting is defined as "the abstinence from all or some kinds of food or drink." Some people fast for religious reasons, while others do it regularly for its potential health perks — such as help with weight management, blood sugar regulation, digestion, and more.
When it comes to intermittent fasting (IF), this approach involves shortening your “eating window” to about 8 or 9 hours each day. Outside of your eating window, you fast (meaning you only drink water, coffee, tea) for the other 16+ hours of the day, including overnight while you're sleeping.
While you can fast any time of year, around the holidays is a great opportunity to give it a try — considering this can help you to keep your calorie intake in check while also promoting more "mindful eating."
What Are The Benefits of Intermittent Fasting?
What's the point of IF? Fasting has a number of positive effects, including regulating your appetite, supporting metabolic health, and reducing inflammation. And the great thing about it is that it doesn't require calorie counting or giving up entire food groups.
When you go long periods of time without consuming food, you give your body, especially your digestive system, a break. It actually requires a lot of energy to break down the food you eat, so fasting allows your body to put its resources towards other things like cellular renewal and tissue repair.
One of the reasons many people try IF is to lose weight, which studies suggest it can help with.
Fasting can help promote insulin sensitivity, meaning it protects against the development of insulin resistance and type 2 diabetes. IF allows levels of insulin, a hormone that's released when you eat, to decrease low enough that your body starts using your stored body fat for fuel. Plus, IF usually means nighttime eating is avoided; this is beneficial because eating late at night has been linked to weight gain and diabetes in a number of studies.
Not only can IF boost your body’s ability to burn fat, but it can also help to stabilize your appetite and reduce emotional eating (i.e, eating due to boredom, routine, etc.).
Fasting encourages you to follow a more structured meal plan, meaning you eat only one or two larger meals per day with less snacking in between. Limiting your eating in this way makes it more likely that you'll put thought into your meals, such as by making them as nutritious and satisfying as possible, and that you'll consume fewer calories overall throughout the course of the day. Even if you enjoy one larger meal on a holiday, if you fast the remainder of the day it's unlikely that you'll gain weight.
A 2020 study published in the American Journal of Clinical Nutrition found that over a period of 12 months, adults who practiced intermittent fasting lost more weight than those following either the Paleo Diet or Ketogenic Diet. In this study, IF was done following the "5:2 protocol," which involves reduced calorie intake two of five days of the week (down to 500 to 700 calories per day).
Adults in the IF group lost an average of 8.8 pounds over the course of the year, plus many experienced other health perks like significant drops in blood pressure levels.
In fact, research suggests that IF regularly can reduce risk factors linked to heart disease, diabetes, unhealthy blood lipid levels, and inflammation that affects the brain — meaning it's a health-promoting tool to consider no matter the time of year.
How To Begin Fasting
Instead of limiting what you eat, intermittent fasting limits when you eat. Here's how to begin:
First, determine which eating window will work best for you depending on your schedule.
You might start by fasting for about 14 hours or 15 hours and limiting your eating window to 8 or 9 hours, such as from 10 AM to 6 PM.
Outside of this window, you don't eat at all but can drink zero-calorie beverages.
Once you get the hang of it, consider fasting for longer stretches of time, perhaps by eating only one or two meals per day. This would work well on a holiday in which you're eating one big meal.
Even though fasting focuses most on meal timing, it's still beneficial and highly recommended that you also eat a healthy diet overall. You'll experience the best results from IF when it's combined with a nutritious diet and regular physical activity. You don't need to count calories but focus on eating mostly or all unprocessed foods.
When you are within your eating window, fill your plate with whole foods like fresh fruits and vegetables, legumes, nuts, seeds, whole grains, fish, and other lean proteins, and healthy fats like avocado and olive oil. These foods provide the essential nutrients you need, plus they are filling and will help to make you feel full for longer.
Is it safe to practice intermittent fasting long-term?
After the holiday season is over, you can certainly continue to incorporate fasting into your routine if you find it's working well for you. You might choose to fast daily by skipping breakfast or try something like the 5:2 protocol mentioned above in which you reduce your calorie intake significantly a couple of times per week.