US researchers found that a weight-loss programme run in primary care clinics reduced patients' BMI and improved their self-esteem. The effects persisted for at least a year after the programme ended.

But weight loss was only modest despite the reduction in BMI, researchers said. They suggested that 'a more intensive intervention might achieve more clinically significant outcomes'.

It comes after NICE's QOF advisory committee rejected a potential indicator for referral to weight management programmes in June last year due to a lack of evidence that weight loss could be sustained over a year or more.

Researchers at the Kaiser Permanente Centre for Health Research in Portland, Oregon invited 208 overweight and obese teenage girls aged 12-17 to take part in the study.

Of these, 105 were randomly assigned to attend series of meetings designed to promote healthy lifestyle. A control group of 103 girls received standard care - an information pack.

Lifestyle behaviour sessions were held weekly for the first three months, then fortnightly for two more.

These included weigh-ins and health education about diet and exercise. Patients were also encouraged to exercise for 30-60 minutes at least five times a week; reduce portion sizes; eat at regular times of the day; and limit time in front of a computer or TV screen.

The meetings also addressed broader psychosocial issues such as body image and self esteem. Twelve group sessions for parents were also provided.

Researchers then used a score based on standardised BMI to measure progress across all patients. Both groups of patients scored 2 before the intervention began.

After 12 months, this score dropped from 2 to 1.85 in patients who had attended the meetings, but fell to just 1.92 in those who had received usual care. Body satisfaction and attitudes to appearance also improved among those attending the sessions.

Researchers concluded: 'Although the magnitude of the effect was modest, these early findings suggest the promise of interventions delivered within primary care settings tailored specifically for teenaged girls.'