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Wolfson Institute of Population Health

Randomised trial of the 5:2 diet

The first randomised evaluation of the 5:2 diet, a popular intermittent energy restriction method of weight management, has been carried out among 300 adults, followed up for a year.

A person measures their waistline

The trial provided information on the effects of a simple brief 5:2 advice compared with standard brief weight management advice, and also on its effects when provided with and without face-to-face support. Results show that a one-off explanation of the 5:2 diet generated modest long-term outcomes similar to those achieved with traditional more complex advice and written instructions concerning diet and exercise, with 18% and 15% of participants respectively in each group losing at least 5% of their body weight at one year. Although the 5:2 diet when accompanied by group support generated better early outcomes, the effect weakened over time. Authors from the Centre for Public Health and Policy's Health and Lifestyle Research Unit conclude that clinicians providing brief advice on weight management may consider recommending 5:2, and that while the approach is not superior to the standard multimodal advice, it is simpler and more attractive to users. 



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