Intermittent Fasting is a touted by influencers and celebrities as a reliable weight loss method, but researchers recently put its effectiveness to the test. Scientists from the Health and Lifestyle Research Unit at Queen Mary University of London [1] conducted a year-long study of 300 adults classified as obese (a BMI of 30 or greater) with co-morbidities (other health conditions), to determine the efficacy of the 5:2 Diet [2]. The findings were published in the journal PLOS One.

How Does the 5:2 Intermittent Fasting Diet Work?

On the 5:2 Intermittent Fasting Diet (a.k.a The Fast Diet) [3] participants eat as they normally would for five days of week. Then on two nonconsecutive days, they either fast or eat close about 500 calories a day. The diet is supposed to result in weight loss, improved digestion, and increased energy.

Who was in the 5:2 Intermittent Fasting Diet Study?

The 300 participants in the study were separated into groups, 200 who went on the 5:2 diet and 100 who didn't. Out of the 200 participants on the 5:2 diet, 100 (5:2G) met once a week for group support weight loss advice sessions where they were able to connect with other participants on their journeys in an advisor moderated environment. The other 100 on the 5:2 diet (5:2SH) were given a "leaflet" and 20 minute session on how to follow the 5:2 diet. Lastly, the control group of 100 (SBA) were given British Heart Foundation [4] guides on weight loss and a 20-minute session with an advisor on how to interpret the guides given to them.

What Were the Results of the 5:2 Intermittent Fasting Diet Study?

By the end of the study researchers found that 18% of people in group 5:2SH lost at least 5% of their body weight, while 15% of people in SBA also lost at least 5% of their bodyweight. Both of these groups also gave their plans "positive ratings" but those who were in group 5:2SH had a larger amount of positive ratings than SBA with. As for group 5:2G, they "generated a greater weight loss at 6 weeks, but by one year, the difference was no longer significant."

Since both 5:2 intermittent fasting groups and the non-fasting group had similar results, researchers concluded that the 5:2 diet isn't extraordinarily better than a regular diet and exercise routine, but it might be an easier way for people to find their calorie deficit and reach their weight loss goals.