The NHS is to focus resources on adults who are obese and can improve their health by losing even a small amount of weight if they keep it off, according to health watchdog NICE.
NICE found that, although the greater the weight loss, the greater the benefit, even a modest weight loss of 3% kept off for life may improve or prevent health problems.
New guidance published by NICE looks at how lifestyle weight management programmes focusing on diet, activity and behaviour change can help people who are overweight or obese to lose weight and to keep it off.
Professor Kate Jolly, professor of public health at the University of Birmingham and NICE guidance developer, said: "Obesity and overweight is an immense problem in our society - with huge personal health cost to individuals and a huge financial cost to the NHS.
"Lifestyle weight management programmes can help people to identify strategies which suit them to help maintain these changes in the future."
Recommendations include referring overweight and obese adults to a lifestyle weight management programme.
However GP practices and other health or social care professionals who give advice about, or refer people to, lifestyle weight management programmes should make it clear that no programme can guarantee long-term success.
For funded referrals, programmes may particularly benefit adults who are obese (that is, with a BMI over 30 kg/m2, or lower for those from black and minority ethnic groups) or with other risk factors (comorbidities such as type 2 diabetes).
Commission programmes that include the core components for effective weight loss and prevent weight regain will last at least 3 months, and sessions will be offered at least weekly or fortnightly and include a ‘weigh-in' at each session.
There will be on-going support once the programme has ended.
Professor Mike Kelly, director of the Centre for Public Health at NICE, said: "Lifestyle programmes are one part of the solution. An environment that makes it easier for people to be active and eat well is also crucial, as are services for people with other issues that affect their health and wellbeing.
"The guidance isn't about quick fixes. There is no ‘magic bullet'. It is about ensuring effective services are there to support people in the long term."