In 2012, around a quarter of adults in England (24% of men and 25% of women aged 16 or older) were classified as obese (body mass index [BMI] 30 kg/m2 or more). A further 42% of men and 32% of women were overweight (BMI 25 to 30 kg/m2) (Statistics on obesity, physical activity and diet: England 2014, Health and Social Care Information Centre 2014).
Although there are people in all population groups who are overweight or obese, obesity is related to social disadvantage (Fair society, healthy lives: strategic review of health inequalities in England post-2010, The Marmot Review 2010).
Prevalence varies by population characteristics (for example see Public Health England briefing papers). For women, obesity prevalence increases with greater levels of deprivation, regardless of the measure used. For men, only occupation-based and qualification-based measures show differences in obesity rates by levels of deprivation.
For both men and women, obesity prevalence decreases with increasing levels of educational attainment. Around 30% of men and 33% of women with no qualifications are obese compared to 21% of men and 17% of women with a degree or equivalent (Statistics on obesity, physical activity and diet: England, Health and Social Care Information Centre 2010).
Obesity is also linked to ethnicity: it is most prevalent among black African women (38%) and least prevalent among Chinese and Bangladeshi men (6%) (Statistics on obesity, physical activity and diet: England, The NHS Information Centre 2006).
Being overweight or obese can lead to both chronic and severe medical conditions (Tackling obesities: future choices – project report, Foresight 2007). It is estimated that life expectancy is reduced by an average of 2 to 4 years for those with a BMI of 30 to 35 kg/m2, and 8 to 10 years for those with a BMI of 40 to 50 kg/m2 (Briefing note: obesity and life expectancy, National Obesity Observatory 2010).
Women who are obese are estimated to be around 13 times more likely to develop type 2 diabetes and 4 times more likely to develop hypertension than women who are not obese. Men who are obese are estimated to be around 5 times more likely to develop type 2 diabetes and 2.5 times more likely to develop hypertension than men who are not obese (Statistics on obesity, physical activity and diet: England, 2011, Health and Social Care Information Centre 2011; Tackling obesity in England, National Audit Office 2001). People who are obese may also experience mental health problems as a result of stigma and bullying or discrimination in the workplace (Puhl and Heuer 2009).
The cost to society and the economy of people being overweight or obese was estimated at almost £16 billion in 2007 (more than 1% of gross domestic product). It could rise to just under £50 billion in 2050 (based on 2007 prices), if obesity rates continue to rise unchecked (Healthy lives, healthy people: a call to action on obesity in England, Department of Health 2011).
The government's obesity strategy 'Healthy lives: a call to action on obesity in England' (Department of Health 2011) aimed to reduce, 'the level of excess weight averaged across all adults by 2020'. It advocated a range of local interventions that both prevent obesity and treat those who are already obese or overweight.
In many areas, public, private or voluntary organisations are commissioned to provide individual or group lifestyle weight management services. People can also self-refer to commercial or voluntary programmes, for example, by attending a local class or 'club' or joining an online programme.
Local policies vary but generally, funded referrals to a lifestyle weight management programme (in tier 2 services) lasts for around 12 weeks or 12 sessions.
There has been uncertainty about which weight management programmes are effective and constitute good value for money. Evidence published since 2006 (such as Loveman 2011) provides an opportunity to refine and clarify best practice (for both self-help and referral schemes) and provide guidance on the commissioning of such programmes.