Is it possible that you have been living off water and kale juice two days a week for nothing? A study has concluded the evidence backing intermittent fasting “does not justify the enthusiasm” for the approach to weight loss, popularised by regimens such as the 5:2 diet.

Researchers could find no good evidence that such diets perform any better than standard dietary advice.

The study, published by the charity Cochrane, looked at 22 clinical trials involving almost 2,000 adults, and concluded that the “hype outpaces the evidence”. Over the course of a year it found there was no meaningful difference between the weight loss in obese people put on conventional diets or those on intermittent fasting diets.

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The diets were popularised by Michael Mosley, the television doctor. Rather than restricting eating in general, they take the approach of limiting it only on set days, but doing so dramatically. Research in mice had suggested that fasting could not only help with weight loss, but also have significant other metabolic benefits, including extending life.

However, Luis Garegnani, the lead author of the study, said that despite their popularity there was a relative paucity of research. What research there was, he said, suggested that “intermittent fasting just doesn’t seem to work for overweight or obese adults trying to lose weight.”

People lost, at best, a few per cent of their body weight. This did not mean it was useless, he said, but it was far from a panacea. “Intermittent fasting may be a reasonable option for some people, but the current evidence doesn’t justify the enthusiasm we see on social media,” he said.

However, Professor Paul Garner, of Liverpool School of Tropical Medicine, said: “Their analysis doesn’t evaluate whether the strategy works for highly motivated people that decide to adopt this strategy of weight loss themselves, rather than have it foisted on them in medical outpatients.”

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Adam Collins, associate professor of nutrition at the University of Surrey, said the study had not considered other mooted benefits. Fasting is, in part, recommended because of a belief that it could lead to changes beyond weight loss.

“Several studies, including our own, have suggested intermittent fasting regimens may offer other metabolic benefits that are independent of weight loss, which is where much of the ­research on these regimens is now ­focused,” he said.

“This makes these approaches more universally useful, not just for those who are overweight or living with obesity, [but] for example, in the management of metabolic disease, and the maintenance of weight once it is lost.”