Losing weight can be incredibly challenging and people will often try several diets before landing on one that helps them drop pounds in a consistent and sustainable manner.
In fact, the findings from a report released by the Centers for Disease Control and Prevention (CDC) in 2020 revealed that 17% of Americans were on diets during the 2017-2018 survey period—up 14% from the decade prior. Yet, the national obesity rate rose from 34% to 42% over that same time period.
Now, new research out of the University of Illinois in Chicago suggests that intermittent fasting (IF) could promote significant weight loss and even improve metabolic health in those who have obesity.
"People love intermittent fasting because it's easy. People need to find diets that they can stick to long term. It's definitely effective for weight loss and it's gained popularity because there are no special foods or apps necessary. You can also combine it with other diets, like Keto," Krista Varady, professor of nutrition at the UIC College of Applied Health Sciences and study author said in a statement.
The review, which was published in the Annual Review of Nutrition, analyzed 25 research studies involving three types of IF. These included the following:
Alternate day fasting: You alternate between one feast day and one fast day. On the fasting day, you only consume one, 500-calorie meal.
5:2 diet: This type of IF calls for five feast days and two fast days per week.
Time-restricted eating: This method doesn't involve calorie restrictions, but you do have to shorten your eating window to anywhere between four and 10 hours a day. Then, you fast outside of that eating window.
Of the studies examined, many showed that time-restricted eating allowed participants with obesity to lose an average of 3% of their body weight—no matter the length of their eating window. On the other hand, those who participated in alternate-day fasting dropped 3%-8% of their body weight over a three to eight-week period.
Surprisingly, those who did the 5:2 diet had comparable weight loss results with those who did alternate-day fasting, despite having fewer fasting periods.
Overall, the percentage of weight participants lost following these two types of IF diets compare to the results one may achieve by following a traditional, calorie-restrictive diet. The best part? Participants who did both of these fasting diets kept the weight off, maintaining an average of 7% weight loss for a whole year.
Bottom line: The study doesn't suggest that IF is more effective than traditional dieting. Instead, it shows that it may be just as effective, so if you hate cutting calories on a daily basis, consider giving either alternate day or 5:2 fasting a try!