5-2 Study
Research type
Research Study
Full title
Short-term effects of standard weight management advice and of the 5-2 diet delivered in self-help or group support format
IRAS ID
195090
Contact name
Peter Hajek
Contact email
Sponsor organisation
Queen Mary, University of London
ISRCTN Number
ISRCTN79408248
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
The 5:2 diet consists of limiting food intake to 500 kcal in women and 600kcal in men on 2 non-consecutive days per week. The diet became popular with extensive reports of success on social media, but there is no scientific evidence so far on whether it works. \n\nA number of clients at our weight clinic have reported their experience with the 5-2 diet and we have now also piloted its use in clinical practice. This identified some barriers such as finding suitable foods and planning meals for the fasting days, but the main hurdle to carrying out the 5-2 diet is the hunger and discomfort on the fasting days. Our experience confirms that people who stick with the programme typically learn to cope with the fasting days well, especially once they see the positive results. We now believe that the diet can be effective with some clients even in its usual self-help format, but that it is likely to work better if group support is included to help people stick with the plan over the first few weeks. This is because after this initial period, the diet should get much easier to maintain without further external support.\n \nWe propose to assess the initial effects of the 5-2 diet compared to state-of-the-art standard brief advice and also to assess 5:2 effects when delivered in self-help format and when accompanied by group support. Apart from assessing effects on weight, the study will also provide information on effects the 5:2 diet have on exercise levels and healthy eating.
REC name
London - Bromley Research Ethics Committee
REC reference
16/LO/0073
Date of REC Opinion
29 Feb 2016
REC opinion
Further Information Favourable Opinion