Intended for healthcare professionals


Randomised controlled trial of four commercial weight loss programmes in the UK: initial findings from the BBC “diet trials”

BMJ 2006; 332 doi: (Published 01 June 2006) Cite this as: BMJ 2006;332:1309
  1. Helen Truby (h.truby{at}, senior lecturer in nutrition and dietetics1,
  2. Sue Baic, lecturer in nutrition2,
  3. Anne deLooy, professor of dietetics3,
  4. Kenneth R Fox, professor of exercise science2,
  5. M Barbara E Livingstone, professor of nutrition4,
  6. Catherine M Logan, PhD student4,
  7. Ian A Macdonald, professor5,
  8. Linda M Morgan, professor of nutritional endocrinology1,
  9. Moira A Taylor, lecturer in nutrition and dietetics5,
  10. D Joe Millward, professor of human nutrition1
  1. 1 School of Biomedical and Molecular Sciences, Centre for Nutrition, Dietetics and Food, University of Surrey, Guildford GU2 7XH,
  2. 2 Department of Exercise and Health Sciences, Centre for Sport, Exercise and Health Sciences, University of Bristol, Bristol BS8 1TP,
  3. 3 Faculty of Health and Social Work, University of Plymouth, Plymouth PL4 8AA,
  4. 4 Northern Ireland Centre for Food and Health, University of Ulster, Coleraine, BT52 1SA,
  5. 5 Centre for Integrated Systems Biology and Medicine, Institute of Clinical Research and School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH
  1. Correspondence to: H Truby
  • Accepted 24 March 2006


Objective To compare the effectiveness of four commercial weight loss diets available to adults in the United Kingdom.

Design Six month multicentre randomised unblinded controlled trial.

Setting Community based sample of otherwise healthy overweight and obese adults.

Interventions Dr Atkins' new diet revolution, Slim-Fast plan, Weight Watchers pure points programme, and Rosemary Conley's eat yourself slim diet and fitness plan.

Main outcome measures Weight and body fat changes over six months.

Results All diets resulted in significant loss of body fat and weight over six months. Groups did not differ significantly but loss of body fat and weight was greater in all groups compared with the control group. In an intention to treat analysis, average weight loss was 5.9 kg and average fat loss was 4.4 kg over six months. The Atkins diet resulted in significantly higher weight loss during the first four weeks, but by the end was no more or less effective than the other diets.

Conclusions Clinically useful weight loss and fat loss can be achieved in adults who are motivated to follow commercial diets for a substantial period. Given the limited resources for weight management in the NHS, healthcare practitioners should discuss with their patients programmes known to be effective.

Trial registration Clinical trials NCT00327821 [].

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