Magical Time-Restricted Eating

Time-restricted eating is a popular concept right now. So naturally it’s great clickbait. Some journals and researchers are happy to seize the opportunity to gain attention. Newly published in the Journal of Nutritional Science, we have an especially sharp example. Jonathan Johnston is grabbing sensational headlines with his study of 13 people for ten weeks.

He reports more fat loss (but not weight loss) and healthier blood glucose levels in people who followed his regimen.

Long Term Benefit?

Johnston told the Telegraph:

This is very encouraging. People can still, to some degree, eat the food that they would like but if they simply change the time at which they eat then that can have a long-term benefit. I would never say it’s a magic bullet, but it could be an important piece of the jigsaw.

The humble brag about a “magic bullet” is bad enough. But the “long-term benefit” claim is completely over the top. This was a 10-week study, for goodness sake!

Many Reasons to Be Skeptical

The first reason to be skeptical of fantastic claims is up front, in the title of the study. This was a “pilot feasibility study.” The only thing a pilot study is designed to prove is that a bigger, meaningful study would be possible. Up front, the researchers have told themselves and the world that this little study can’t prove anything else. Only seven subjects actually followed the time-restricted eating program. The other six served as a control group.

The study has other issues, as Indiana University researcher Andrew Brown explained to us. For example, he said:

It is important to note the time-restricted feeding was compared to habitual behaviors. So there is a mechanistic question. Was it was the time of day or just changing habits at all that made the difference? Perhaps the TRF group was now paying much closer attention to their eating.

In addition, Brown pointed us to the difficulty of following this regimen. Subjects gave it an average rating of seven on a scale of one to ten. One is easy. Ten is extremely difficult. The researchers reported that most of the participants “could not have maintained the TRF protocol beyond 10 weeks” – mainly because it was incompatible with their lives.

Johnston was absolutely right. He should never say “magic bullet.”

Click here for the study, here for the press release from the University of Surrey, and here for the story by the Telegraph.

Time Flows, photograph © Nicola Albertini / flickr

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September 19, 2018