Overweight and obesity
While the major risk factors for coronary heart disease - smoking, raised blood pressure and high blood cholesterol levels - have been falling or have remained fairly static over the last few decades, the prevalence of two other important contributors to coronary heart disease obesity and type 2 diabetes risk has been rising.
It is estimated that about 5% of deaths from coronary heart disease in men and 6% of deaths from coronary heart disease in women are due to obesity. This is defined as a body mass index (BMI) of greater than 30 kg/m2.
These proportions of coronary heart disease deaths could be avoided if the UK population were to reduce its BMI to below 27.526 (a figure still considered overweight but not obese). A more realistic 25% reduction in the UK prevalence of obesity would bring about only a 1.2% and 1.4% decline in coronary heart disease deaths for men and women, respectively.
Overweight is strongly linked with high blood pressure and diabetes and being obese is linked with higher levels of total blood cholesterol.
It's unclear whether obesity is an independent risk factor for coronary heart disease or whether its effect is mediated through these other risk factors. Overweight and obesity are in themselves influenced by diet and by physical activity.
Body Mass Index (BMI) and waist circumference
Body Mass Index (BMI) is calculated by dividing weight in kilograms by the square of height in metres. The ideal is between 21 and 25, and the preferable waist circumference is no more than 88cm (35 inches) for women, 102 cm (40 inches) for men.
Trends in overweight and obesity
In England, 43% of men and 33% of women are overweight (a BMI of 25-30 kg/m2), and an additional 22% of men and 23% of women are obese (a BMI of more than 30 kg/m2), according to Department of Health's Health Survey for England 2003.
However, more than 12 million adults and one million children may be obese by 2010 the Department of Health's Forecasting Obesity to 2010 report warns. Nearly one third of men will be obese by 2010 the government predicts, if we don't make changes to our lifestyles.
Overweight / obesity and age
Overweight and obesity increase with age, with about 27% of men and 31% of women aged 16-24 classified as overweight or obese, rising to about 79% of men and 71% of women classified as overweight or obese by age 55-64.
Forecasting Obesity to 2010's findings show that girls will overtake boys in the obesity stakes, with nearly 1 in 5 girls aged 2-10 expected to be obese by 2010. In 2004, the government set the target to halt the year-on-year increase in obesity among children under the age of 11 in England by 2010, in the context of a broader strategy to tackle obesity in the population as a whole.
Childhood obesity in 2006
International Obesity Taskforce research published in spring 2006 suggests that almost two million UK school children are overweight and 700,000 are obese. The study shows that more than a quarter of girls and over a fifth of boys are fatter than they should be.
This is not just a British problem as the Obesity Taskforce states that by 2010 the number of overweight children across the EU is set to top 26 million within four years, with 6.4 million of them being classed as obese. In the EU, the number of children who are overweight is expected to rise by 1.3 million children a year, with more than 300,000 of them becoming obese each year without urgent action to counteract the trend. In the EU, the number of children who are overweight is expected to rise by 1.3 million children a year, with more than 300,000 of them becoming obese each year without urgent action to counteract the trend.
The adverse impact on health has also led researchers to suggest that, based on the most conservative estimate, over 20,000 obese children in the EU have type 2 diabetes, while over 400,000 have impaired glucose tolerance. Over a million obese children are likely to show a range of indicators for cardiovascular disease, including hypertension and raised blood cholesterol levels, and have three or more indicators of the metabolic syndrome. Over 1.4 million may have early stages of liver disorder.
For further information visit: http://www.iotf.org/
Overweight / obesity and social class
Obesity is more common among adults from manual occupations. Twenty-five per cent of women in manual occupations are classified as obese, compared with one in seven women employed in a professional role.
Overweight / obesity and ethnicity
Men
Levels of obesity are much lower in Pakistani, Indian, Chinese and Bangladeshi men than among men in the general population. However, South Asian men are more likely to have a high waist to hip ratio than the general population, indicating the distribution of fat around the abdomen (central obesity). Such a pattern of fat distribution is associated with a higher risk of coronary heart disease than fat distributed more evenly about the body or on the hips. In 2005 the World Health Organisation recommended a BMI of 23.
Women
Among women, obesity prevalence is high for Black Caribbean and Pakistani women and low for Bangladeshi and Chinese women. However, all female minority ethnic groups have levels of central obesity at least twice that of the general female population.
Obesity Care Pathway expected
The National Institute for Health and Clinical Excellence (NICE) has been commissioned to prepare definitive guidance on the prevention, identification, management and treatment of obesity. This is expected to be published in February 2007 after full consultation. Meanwhile, the Department of Health's interim Obesity Care Pathway is intended for use by front line health professionals working in primary care.
A list of the organisations and potential users consulted in 2005/2006 is available at: http://www.publications.parliament.uk/pa/cm200506/cmhansrd/cm051219/text/51219w94.htm
NICE's 'Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children' first draft guideline for consultation was published in March 2006. Visit: http://www.nice.org.uk/
EU Commission Green Paper
The EU Commission's Green Paper on the promotion of healthy diets and physical activity has finished a public consultation on how to reduce obesity levels and associated chronic diseases in the EU. The public consultation ran until 15 March 2006, with a report published on the Commission's website June 2006. This was promoted by the fact that 14 million children in the European Union are overweight - and more than 3 million of these are obese. What is equally concerning is that this number is rising by 400,000 a year. The Green Paper called for concrete suggestions on action at a European level which could complement, support and coordinate existing national measures.
The Green Paper is available at: http://www.foodstandards.gov.uk/aboutus/ourboard/boardmeetoccasionalpapers/diets