Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Susan Jebb


Contact details

MRC Human Nutrition Research
Elsie Widdowson Laboratory
120 Fulbourn Road
United Kingdom
+44 (0)1223 426356

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A randomised controlled trial to investigate the effectiveness of two commonly-used lifestyle-based weight-loss programmes across three countries


WW Global Effectiveness Trial

Study hypothesis

The purpose of the study is to compare the effectiveness of WeightWatchers (WW), a commercial weight-loss programme, with current standard General Practitioner (GP) weight-loss treatment for overweight adults, as informed by national guidelines in three countries (the UK, Australia and Germany).

Ethics approval

1. UK: Nottingham Research Ethics Committee 2, 30/04/2007, ref: 07/Q2404/40
2. Australia: Sydney SW Area Health Service (RPAH Zone), 14/05/2007, ref. X07-0089
3. Germany: Ethics Committee of Fakultat (Ethikkommission de Fakultat fur Medizin der TUM), 18/05/2007, ref. 1812/07

Study design

12-month multi-centre randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

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


Overweight and obesity


GP referral to WW for 12 months versus standard GP management for weight loss for 12 months.

Intervention type



Drug names

Primary outcome measure

To examine the differences in weight loss at 12 months between the WW programme and standard GP management for weight loss (as informed by national guidelines) across three countries.

Secondary outcome measures

1. To investigate numbers of subjects losing 5% and 10% of baseline weight in each group
2. To investigate changes in a number of indicators of metabolic disease in both groups - to include body composition (bio-impedance analysis), simple indices of insulin sensitivity (HOMA-IR) , lipid profile, liver function and inflammatory markers, measured at baseline and at 6 and 12 months
3. To explore the impact of the treatments on eating behaviour (Three Factor Eating Questionnaire [TFEQ-R21]), physical activity (International Physical Activity Questionnaire short version [IPAQ-short]) and quality of life (Impact of Weight on Quality Of Life [IWQOL-lite]), assessed at baseline and at 6 and 12 months
4. To examine cost of the WW programme vs standard GP care for weight loss
5. To investigate the temporal pattern of change in body weight over all measured time points
6. To qualitatively explore participants' experiences of the two weight-loss programmes (focus groups), assessed at baseline and at 6 and 12 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Men and women who are overweight and with evidence of some increased risk of obesity-related disease will be eligible for the trial. Participants will be male and female adults aged 18+ years, with a body mass index of 27 - 35 kg/m^2 and one or more of the following risk factors:
1. Family history of diabetes mellitus
2. Controlled type 2 diabetes mellitus not treated with insulin*
3. Previous gestational diabetes mellitus
4. Impaired glucose tolerance/impaired fasting glycaemia
5. Mild-moderate dyslipidaemia, or treatment for dyslipidaemia
6. Treatment for hypertension
7. Central adiposity (waist circumference greater than 88 cm in women or greater than 102 cm in men)
8. Polycystic ovary syndrome/infertility without apparent cause other than weight
9. Lower limb osteoarthritis
10. Abdominal hernia

* Patients with type 2 diabetes treated with sulphonylureas will be eligible for inclusion but GPs will be advised to instruct them to closely monitor their glucose levels due to the additional risk of hypoglycaemia during weight loss, and to regularly review their medication. The number of people with diabetes recruited to the study will be limited to a maximum of 50% of the total sample.

Participant type


Age group




Target number of participants

804 (268 per country)

Participant exclusion criteria

Factors which may affect weight:
1. Recent weight loss of greater than 5 kg in the previous 3 months
2. History of clinically-diagnosed eating disorder
3. Orthopaedic limitations preventing participation in regular physical activity
4. Untreated thyroid disease or greater than one change in thyroid medication over previous 6 months
5. Taking any prescription medication with known effects on appetite or weight (according to National Medicines Formulary)
6. Taking oral steroids
7. Chronic/inflammatory gastrointestinal disorders (irritable bowel syndrome acceptable)
8. Previous surgical procedure for weight loss
9. Major surgery within previous 3 months
10. Pregnancy or lactation

Co-exisiting disease:
11. Insulin-treated diabetes mellitus
12. HbA1c greater than 9.0%
13. Diagnosis of type 2 diabetes within previous 6 months
14. Heart problems within previous 3 months (e.g. angina, myocardial infarction, stroke) or implanted cardiac defibrillator or pacemaker
15. Uncontrolled hypertension (greater than 160/95 mmHg)
16. Having started taking a new prescription medication within 3 months
17. Change in dosage of a prescription medication within 1 month
18. History or presence of cancer (completely resected basal or squamous cell carcinoma acceptable if treatment completed more than 6 months prior to enrolment)

Participants will also be excluded if they have participated in another clinical trial within 30 days prior to enrolment.

Participants must be willing to be involved in a lifestyle-based weight-loss programme for a 12-month period, and able to attend weekly meetings (free of charge) for the duration if required.

Recruitment start date


Recruitment end date



Countries of recruitment

Australia, Germany, United Kingdom

Trial participating centre

MRC Human Nutrition Research
United Kingdom

Sponsor information


Medical Research Council Human Nutrition Research (UK)

Sponsor details

c/o Dr Ann Prentice
MRC Human Nutrition Research
Elsie Widdowson Laboratory
120 Fulbourn Road
United Kingdom
+44 (0)1223 426356

Sponsor type




Funder type


Funder name

WeightWatchers International Inc. (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2011 results in:
2013 cost-effectiveness results in:
2014 results in:
2018 results in:

Publication citations

  1. Results

    Jebb SA, Ahern AL, Olson AD, Aston LM, Holzapfel C, Stoll J, Amann-Gassner U, Simpson AE, Fuller NR, Pearson S, Lau NS, Mander AP, Hauner H, Caterson ID, Primary care referral to a commercial provider for weight loss treatment versus standard care: a randomised controlled trial., Lancet, 2011, 378, 9801, 1485-1492, doi: 10.1016/S0140-6736(11)61344-5.

  2. Fuller NR, Colagiuri S, Schofield D, Olson AD, Shrestha R, Holzapfel C, Wolfenstetter SB, Holle R, Ahern AL, Hauner H, Jebb SA, Caterson ID, A within-trial cost-effectiveness analysis of primary care referral to a commercial provider for weight loss treatment, relative to standard care--an international randomised controlled trial., Int J Obes (Lond), 2013, 37, 6, 828-834, doi: 10.1038/ijo.2012.139.

  3. Results

    Fuller NR, Williams K, Shrestha R, Ahern AL, Holzapfel C, Hauner H, Jebb SA, Caterson ID, Changes in physical activity during a weight loss intervention and follow-up: a randomized controlled trial, Clin Obes, 2014, 4, 3, 127-135, doi: 10.1111/cob.12057.

Additional files

Editorial Notes

06/07/2018: Publication reference added.