Chances are good that you know someone who has adopted an eating pattern that reflects some version of intermittent fasting (IF) over the last few years. IF has gained positive attention for many reasons, from weight loss and improved metabolic health to claims of a lengthened lifespan. Its popularity has even outgrown that of other frequently talked about diets as they wax and wane in the spotlight, like the clean eating lifestyle, the ketogenic diet, and the Whole30 eating plan.  

The Growing Popularity of Fasting

In a time when it seems like the latest and greatest dietary trends are always changing, fasting has become incredibly popular. In fact, the practice of intermittent fasting seems to have beat out numerous other eating patterns and for good reason. 

Diet trend surveys have found that the popularity of intermittent fasting has exploded. In fact, IFIC Foundation’s Food and Health Survey found that intermittent fasting is one of the most followed diets among people over the last few years.[1]

As with many health-related trends, the initial popularity of IF was likely snowballed by celebrities talking about their positive experiences with the eating pattern. This was paired with the release of several best-selling books and documentaries that highlighted the benefits and guidelines to doing IF, such as Fasting and Eating for Health by Dr Joel Fuhrman, The Obesity Code by Dr. Jason Fung, and The 5:2 Diet by Kate Harrison. These platforms and resources allowed the word of IF to spread around the globe quickly and the fasting community to grow.

What is Intermittent Fasting?

Intermittent fasting is a way of eating that incorporates regular periods of not eating, between periods of scheduled food intake. It’s a more structured way of eating than many other dietary approaches, but also comes with more freedoms than traditional diet programs. 

IF can be done in a number of ways, which is one reason many people like it so much. For instance, the 16/18 method involves fasting every day for 14-16 hours, and having a restricted eating window of 8-10 hours every day. 

The 5:2 method involves eating normally for five days of the week, and fasting through a restricted calorie intake (usually sticking between 500-600 calories) for the other two days. The Eat, Stop, Eat approach involves undergoing a 24 hour fast once per week. The Warrior Diet is structured in a way that allows a large meal at night, but only small portions and snacks during the rest of the day. 

As you can see, IF isn’t a one-size-fits-all plan and there are several ways you might choose to go about your eating and non-eating periods. IF may take some experimentation to see which one feels the best, especially if you experience unwanted side effects from certain approaches, like fatigue, headaches, or hunger. 

Ultimately, you can decide which pattern makes the most sense for your lifestyle and which will be the most sustainable in support of your short- and long-term health goals. This makes it very attractive to people wanting some structure, but not too many rules.

What Makes Fasting Different

While other popular ways of eating, like a ketogenic diet, a vegan diet, or a low-carb diet, focus on the type of food you’re eating, IF focuses on the periods of time you will and will not be eating. 

IF doesn’t require calorie counting, measuring ketones or blood sugar, or tracking your macros, which are the foundation of many other dietary approaches. Instead, IF gives you just the right amount of structure while still allowing freedom to make your everyday food choices.

This gives you more freedom to choose the types, and amounts of foods you’ll focus on while following a predetermined schedule of eating and fasting windows each day or week. Regardless of which pattern you choose, the underlying reason IF works for weight loss is because you are restricting your eating period and typically your caloric intake as well. 

However, this doesn’t mean IF is a free-for-all when it comes to nutrition. IF is intended to emphasize healthy eating choices, including whole foods, fruits and vegetables, and water intake, but it gives this control to you. 

You will of course also feel better – and reap far more health benefits – if the foods you choose during eating periods are of high nutritional quality. Even though IF is seen as more of a lifestyle than a diet, it’s important to highlight that benefits are unlikely if you’re not choosing healthy foods most of the time. 

Reducing, or eliminating, highly processed, packaged foods and items of poor nutritional value is still recommended in all approaches to IF. If you’re choosing foods that are high in added sugar and low in fiber and complex carbohydrates, you’re going to be more likely to experience a sugar crash and other unwanted symptoms.

Benefits of Intermittent Fasting

In addition to flexibility, intermittent fasting may offer other benefits that draw people to the lifestyle, especially if they have a specific goal in mind, like weight loss. Some research indicates that certain IF patterns, like alternate day fasting, are about as effective as low-calorie diets for losing weight. 

A 2018 meta-analysis of six studies ranging from 3-12 months in length examined whether different approaches to intermittent fasting were a reliable way to promote weight loss. The authors found that a variety of intermittent fasting patterns were more effective for weight loss than no treatment or change in diet at all.[2] 

Other research has indicated that certain types of intermittent fasting may benefit metabolic health, but the true benefit depends on how sustainable the eating pattern is for the individual.[3]  For instance, some studies have found that IF may result in weight loss associated with improved blood sugar and total cholesterol that, in turn, may have positive effects on type 2 diabetes, heart disease, or cancer risk.[4] 

IF has many incredible benefits. Keep in mind that IF is not for everyone, and it’s not recommended for certain populations, such as individuals struggling with eating disorders, or women who are pregnant or lactating. It’s a good idea to consult with a medical provider to make sure IF is a safe and appropriate eating pattern for you to adopt.

It seems that with its flexibility and potential benefits, various versions of IF may be around to stay even as other diet and health trends come and go as usual.