Condition category
Nutritional, Metabolic, Endocrine
Date applied
19/07/2016
Date assigned
21/07/2016
Last edited
19/07/2016
Prospective/Retrospective
Retrospectively registered
Overall trial status
Ongoing
Recruitment status
Recruiting

Plain English Summary

Background and study aims
The 5:2 diet consists of limiting food intake to 500 calories in women and 600 calories in men on two 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. A number of clients at our weight clinic have reported their experience with the 5:2 diet and we have now also tested it 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. The aim of this study is to assess the initial effects of the 5:2 diet compared to state-of-the-art standard brief advice, and also to assess the effects of the 5:2 diet 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 has on exercise levels and healthy eating.

Who can participate?
Patients aged 18 and over who are overweight or obese (BMI ≥30kg/m2, or BMI≥28kg/m2 with other illnesses [comorbidities])

What does the study involve?
Participants are randomly allocated to one of three groups.
The first group receive a 20-minute session on the 5-2 plan and a written guide on how to use it with recommendations for internet resources along with a leaflet listing local resources for exercise. Participants are encouraged to purchase and use pedometers to increase their exercise levels and to assess their weight weekly. Participants are asked to reduce their energy intake on two non-consecutive days per week to 500 calories for women and 600 calories for men.
The second group receive a brief explanation of the 5:2 plan and are booked for six weekly group support sessions. The sessions focus on helping clients to adhere to 5:2, share coping and fasting strategies and maintain motivation. Each session lasts for about one hour and groups comprise of 10-20 participants. Participants also receive a leaflet listing local resources for exercise and are encouraged to purchase and use pedometers to increase their exercise levels and to assess their weight weekly. Participants are asked to reduce their energy intake on two non-consecutive days per week to 500 calories for women and 600 calories for men.
The third group receive a 20-minute session with an advisor focusing on healthy eating and physical activity and instructions on using the ‘Facts not Fads’ and the ‘Get Active, Stay Active’ British Heart Foundation self-help guides, supplemented by the NHS Change 4 Life series of booklets and a leaflet listing local resources for exercise. Participants are encouraged to use pedometers to increase their exercise levels and to assess their weight weekly.

What are the possible benefits and risks of participating?
The main benefit to the participant is the chance to try a treatment that could enhance the likelihood of achieving and maintaining a beneficial amount of weight loss. We do not forsee any potential risks to participants.

Where is the study run from?
Queen Mary University of London (UK)

When is the study starting and how long is it expected to run for?
November 2015 to January 2018

Who is funding the study?
Medical Research Council (UK)

Who is the main contact?
Sarrah Peerbux
s.peerbux@qmul.ac.uk

Trial website

Contact information

Type

Public

Primary contact

Ms Sarrah Peerbux

ORCID ID

Contact details

Health and Lifestyle Research Unit
Wolfson Institute of Preventive Medicine
Queen Mary University of London
2 Stayner's Road
London
E1 4AH
United Kingdom
+44 (0)207 882 5948
s.peerbux@qmul.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

n/a

Study information

Scientific title

Short-term effects of standard weight management advice and of the 5-2 diet delivered in self-help or group support format

Acronym

5-2 Study

Study hypothesis

The study will evaluate whether the 5-2 diet combined with multi-session behavioural support results in greater weight loss compared to the 5-2 diet delivered in a self-help format and standard advice on diet and physical activity.

Ethics approval

London - City Road & Hampstead Research Ethics Committee, 29/02/2016, ref: 16/LO/0073

Study design

Randomised controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Community

Trial type

Treatment

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet

Condition

Obesity

Intervention

Randomisation would be computer-generated by the study statistician, using envelopes to reveal the randomisation allocation.

5-2 self-help (5-2 SH) arm would receive a 20-minute session on the 5-2 plan and a written guide on how to use it with recommendations for internet resources along with a leaflet listing local resources for exercise. Participants will be encouraged to purchase and use pedometers to increase their exercise levels and to assess their weight weekly. In both 5-2 arms, participants will be asked to reduce their energy intake on two non-consecutive days per week to 500 calories for women and 600 calories for men. Participants will be seen by Research Health Psychologists.

5-2 plus group support (5-2 GS) arm would receive a brief explanation of the 5-2 plan and will be booked for six weekly group support sessions. Participants would also receive a leaflet listing local resources for exercise and will be encouraged to purchase and use pedometers to increase their exercise levels and to assess their weight weekly. The sessions will focus on helping clients to adhere to 5-2, share coping and fasting strategies and maintain motivation. Each session would last for approximately one hour and groups will comprise of 10-20 participants. Research Health Psychologists will run the groups.

Standard advice self-help (SH) arm would receive a 20-minute session with an advisor focusing on healthy eating and physical activity and instructions on using the ‘Facts not Fads’ and the ‘Get Active, Stay Active’ British Heart Foundation self-help guides, supplemented by the NHS Change 4 Life series of booklets and a leaflet listing local resources for exercise. Participants will be encouraged to use pedometers to increase their exercise levels and to assess their weight weekly. Participants will be seen by Research Health Psychologists.

Intervention type

Behavioural

Phase

Drug names

Primary outcome measures

Weight loss at 6 months

Secondary outcome measures

1. Changes in weight, blood pressure, dietary habits (measured by the Fat and Fiber related Diet Behaviour Questionnaire), exercise levels (measured by the International Physical Activity Questionnaire) and proportion of participants losing at least 5% of their body weight at 6 weeks and 6 months and the self-reported change in weight at 3 months. Dietary habits and exercise levels will be assessed at baseline, 6 weeks and 6 months only
2. Adherence to the three interventions, determinants of adherence, and barriers and facilitators to adherence at 6 weeks, 3 and 6 months

Overall trial start date

01/11/2015

Overall trial end date

30/01/2018

Reason abandoned

Eligibility

Participant inclusion criteria

1. Age 18 years and older
2. BMI≥30kg/m2, or BMI≥28kg/m2 with comorbidities

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

300 participants

Participant exclusion criteria

1. Women who are pregnant, breastfeeding or planning to conceive in the next 6 months
2. History of eating disorders
3. Currently involved in another research project
4. Currently using 5:2 diet
5. Non English speakers
6. Unavailable for 6 month follow-up
7. BMI>45kg/m2
8. Lost more than 5% of their body weight in the last 6 months
9. Taking medication prescribed by a psychiatrist (these medications can affect weight and psychiatric illness makes adherence to long-term programs difficult)
10. Diabetics who require insulin

Recruitment start date

27/06/2016

Recruitment end date

01/06/2017

Locations

Countries of recruitment

United Kingdom

Trial participating centre

Queen Mary University of London
Wolfson Institute of Preventive Medicine Health and Lifestyle Research Unit 2 Stayner's Road
London
E1 4AH
United Kingdom

Sponsor information

Organisation

Queen Mary University of London (UK)

Sponsor details

Joint Research Management Office
Queen Mary Innovation Centre
5 Walden Street
London
E1 2EF
United Kingdom

Sponsor type

University/education

Website

Funders

Funder type

Research council

Funder name

Medical Research Council

Alternative name(s)

MRC

Funding Body Type

private sector organisation

Funding Body Subtype

other non-profit

Location

United Kingdom

Results and Publications

Publication and dissemination plan

Study results will be published in a peer-reviewed journal and may be presented at scientific conferences.

Intention to publish date

30/01/2019

Participant level data

To be made available at a later date

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes