GP referral to Weight Watchers avoided type 2 diabetes in third of patients

The initiative also helped more than half of those referred either to reduce their risk of developing diabetes or to get their blood sugar levels back to normal.

The number of people diagnosed with type 2 diabetes in the UK has increased from 1.4 to 2.9 million since 1996. A new diagnosis is made every 2 minutes, and by 2025, an estimated 5 million people will have the condition.

Risk of developing type 2 diabetes is strongly influenced by lifestyle factors, but can be significantly reduced by weight loss, achieved by eating less and exercising more.

And the UK's national health and social care guidance organisation, the National Institute for Health and Care Excellence (NICE) says that certain commercial weight management providers, such as Weight Watchers, can help obese people to shed the pounds.

A US study showed that participation in a commercial weight management programme succeeded in reversing progression to type 2 diabetes. But the effectiveness of this approach in UK primary care has not been fully evaluated.

So the researchers identified 166 patients from 14 general practice surgeries at high risk of developing type 2 diabetes: those with impaired glucose regulation known as pre-diabetes or non-diabetic hyperglycaemia; and with a body mass index (BMI) above 30 kg/m2.

These patients were then invited to contact Weight Watchers to book a place on their diabetes prevention programme, which included a 90-minute induction session followed by 48 weekly group meetings.

From among the 166 primary care referrals, 149 patients were eligible. Some 117 attended the induction and 115 started the weekly sessions, representing a take-up rate of 70%, which is high for a lifestyle intervention, say the researchers.

The programme focused on improving diet quality, reducing portion size, increasing physical activity levels, as well as boosting confidence in the ability to change and a commitment to the process.

Blood tests were repeated at 6 and 12 months to check on risk factors, and any changes in weight were recorded by Weight Watchers.

Analysis of the results showed that the initiative led to an average fall in HbA1c (a measure of average blood glucose levels over several weeks) of 2.84 mmol/mol after 12 months to levels regarded as normal.

Blood glucose levels also returned to normaI in more than a third (38%) of the patients and only 3% developed type 2 diabetes after 12 months.

The average weight loss amounted to 10 kg at the 12 month time point (a reduction in BMI of 3.2kg/m2).

The researchers acknowledge that not all patients at high risk go on to develop type 2 diabetes, added to which the referral numbers were low, based on the funding available, with few black or minority ethnic participants, men, or those on low incomes.

Nevertheless, they conclude that the initiative has the potential to have considerable impact.

"A UK primary care referral route partnered with this commercial weight management provider can deliver an effective diabetes prevention programme," they write. "The lifestyle changes and weight loss achieved in the intervention translated into considerable reductions in diabetes risk, with an immediate and significant public health impact."