2 Public health need and practice
In England in 2010, just over a quarter of adults (26%) and almost a sixth of children (16%) aged 2 to 15 years were obese (The Health and Social Care Information Centre 2012). By 2050, 60% of adult men, 50% of adult women and 25% of children may be obese (Foresight 2007). Adults with a body mass index (BMI) more than or equal to 30 kg/m2 are classified as obese, as are children with a BMI over the 95th percentile – based on the 1990 UK reference population (The Health and Social Care Information Centre 2012).
Differences in measurement methods make comparison with other countries difficult. However, the prevalence of obesity in England is at least as high, if not higher, than in other EU countries. While there is some suggestion that it may be starting to level off among children in England (McPherson et al. 2009; The Health and Social Care Information Centre 2012), prevalence remains very high among this group.
Obesity is related to social disadvantage with marked trends, especially in children, by area of residence (The Marmot Review 2010). It is also linked to ethnicity. Obesity is most prevalent among Black Caribbean, Black African and Irish men – and least prevalent among Chinese and Bangladeshi men. Among women, it is more prevalent among those of Black African, Black Caribbean and Pakistani origin – and least prevalent among Chinese women (The Health and Social Care Information Centre 2008).
Around 58% of cases of type 2 diabetes, 21% of cases of heart disease and between 8% and 42% of certain cancers (endometrial, breast, and colon) are attributable to excess body fat (Foresight 2007).
Obesity reduces life expectancy by an average of 9 years and is responsible for 9000 premature deaths a year in England. In addition, people who are obese can experience stigmatisation and bullying that can lead to depression and low self-esteem (Foresight 2007).
It is estimated that overweight and obesity now costs the NHS £5.1 billion per year (Scarborough et al. 2011). However, if current trends continue, these costs will increase by an additional £1.9 billion per year by 2030 (Wang et al. 2011). In 2007, the cost to the wider economy was £16 billion – this is predicted to rise to £50 billion a year (at today's prices) by 2050 if left unchecked (Foresight 2007).
The determinants of obesity are complex. Factors include: genetic disposition, early life nutrition and growth, individual lifestyle, psychological issues, the physical and cultural environment, food production and consumption, education, social and economic factors and the influence of the media (Foresight 2007).
Existing NICE guidance indicates the type of national and local interventions that can be used to tackle obesity and improve people's diet and physical activity levels. (Existing guidance covers settings such as primary care, schools and workplaces.) However, none of the recommendations have considered the synergy between discrete policies or 'packages' of interventions and the complex organisational issues involved in local delivery.
To date, no country has managed to reverse the rising rates of obesity at a population level. The Foresight report (2007) argued that a wide range of partners should work together to develop and implement community-wide approaches to tackle the determinants. More recently, the white paper 'A call to action on obesity in England' has reinforced the importance of synergistic efforts at a range of levels, including local action (DH 2011).
However, it remains unclear how such an approach can best be implemented. Community-based programmes are notoriously difficult to evaluate and often do not lend themselves to traditional research designs. Current practice is patchy and is dominated by short-term single interventions, usually developed and implemented through a 'top-down' approach. Integrated, coordinated action that feeds into an overarching, long-term strategy is uncommon.
In addition, commissioners often find it difficult to decide whether to allocate funds to prevention or treatment, although it is clear that there is a need for both to operate in tandem (DH 2011).