What is obesity and how to manage it ?
This article describes the worldwide obesity epidemic, including the definition of obesity, its prevalence and health consequences, and the policies and guidelines available for obesity management.
Obesity has become a worldwide epidemic, estimated to affect approximately 300 million individuals across the globe (Blackburn et al., 2009).Indeed, obesity, which is the clinical term used to describe excess body fat, is now classified as a chronic condition.The most frequently utilised measure of obesity is the objective measure of Body Mass Index (BMI), which is measured by dividing an individual’s weight by the square of their height.In adults, a BMI of 25-29.9kg/m2 is considered overweight whilst a BMI of >30kg/m2 is considered obese.
In the UK, the prevalence of overweight and obesity in adults has been increasing over the past 30-years (DH, 2002; NHS Information Centre, 2009a). Between 1993 and 2008, a total of 37% of individuals aged 16-years and over were overweight and 25% obese (NHS Information Centre, 2009b). A ‘Foresight report’ conducted by Sheffield Hallam University indicates that if obesity continues to rise, as many as 36% of men and 28% of women will be obese by 2015 (Aylott, Brown, Copeland, & Johnson, 2008).This could increase further to 60% in men and 50% in women, respectively, by 2050.This increase has dire consequences for individual health and well-being.In addition, the societal costs of obesity continue to raise concern.The most recent figures show the total cost of obesity in the UK to be £7 billion annually (Aylott, et al., 2008).This is likely to rise to £50 billion by 2050.
Obesity is associated with an increased risk of chronic disease and comorbidity, including diabetes, hypertension, coronary artery disease, stroke, and various cancers (Kopelman, 2007).In particular, diabetes is likely to increase as obesity prevalence increases; 90% of individuals with type 2 diabetes are reported to be overweight or obese.There is a 20-80 times increased risk of developing type 2 diabetes for individuals who are obese compared with non-obese individuals (McPherson et al., 2007).Obesity is also associated with the four most prevalent disabling conditions in the UK, namely arthritis, mental illness, learning disabilities, and back problems (Ellis et al., 2006). The likelihood of having a disability is greater among obese individuals compared to individuals of healthy weight.Indeed, it has been found that individuals who are obese are twice as likely to develop a physical disability.They have an 84% increased risk of developing musculoskeletal conditions such as joint or muscle pain, a 35% increased risk of back problems, and four times the risk of developing arthritis (Ellis et al., 2006).
The key independent predictors of obesity have been found to be older age, smoking status, self-reported unhealthy diet, lack of physical activity, and hypertension (NHS Information Centre, 2009).Income and alcohol consumption have also been found to play a role in obesity.Obesity is thus primarily a condition of lifestyle that is preventable.Indeed, lifestyle interventions are the first course of action in tackling obesity.Despite body weight being influenced by genetic and environmental factors, research shows that an individual’s lifestyle significantly influences whether or not they are able to maintain a healthy weight (Aylott, et al., 2008). The World Health Organisation (WHO) state that “there is convincing evidence that a high intake of energy dense foods promotes weight gain” (p. 101) and that “Energy expenditure through physical activity is an important part of the energy balance equation that determines body weight” (p.16).Indeed, the evidence suggests that an individual needs to manage their ‘energy balance’ to maintain a healthy weight so that energy intake (calories from food) does not exceed energy output (calories burned through physical activity) (NICE, 2006).Lifestyle advice for managing weight includes a high intake of dietary fibre and a total of at least 30-minutes daily moderate intensity physical activity on five or more days of the week (WHO, 2003; DH, 2004).
The National Institute of Clinical Excellence (NICE, 2006) have recommended that pharmacological treatments for obesity are only considered if changes to lifestyle have been unsuccessful. Orlistat or Sibutramine are the two most widely prescribed pharmacological treatments for both weight loss and weight maintenance, although continued lifestyle advice and support alongside the drugs is emphasised (NICE, 2006).As an example, it has been advised that Orlistat is only prescribed to adults with a BMI of >28.0kg/m2 or additional risk factors or to adults with a BMI of >30.0 kg/m2.
When lifestyle interventions and pharmacological treatments fail, bariatric surgery is recommended for reducing the risk of obesity-related comorbidities (Adams et al., 2007; Sjostrom et al., 2007).Indeed, recommendations have been made that the Government should make efforts to increase the availability of bariatric surgery for individuals who are morbidly (CREST, 2005).The two main types of bariatric surgery are restrictive surgeries and malabsorptive surgeries.The former includes gastric banding, a restrictive operation that creates a small neogastric pouch to decrease quantity of food intake.The latter includes gastric bypass, where malabsorptive procedures are carried out to rearrange the small intestine in order to decrease the nutrient absorption efficiency of the intestine.In general, restrictive surgery is considered easier and safer, although is likely to lead to less long-term weight loss (Blackburn & Jones, 2006). Furthermore, mortality and serious medical complications have been reported as a result of surgery (Livingston & Langert, 2006). Individuals who receive bariatric surgery require nutritional supplements and medical monitoring for the rest of their lives, which is why it is usually only provided to individuals with a BMI of >40kg/m2 (Fobi, 2004).
The Government has made obesity a priority for intervention, with particular efforts being made to educate people regarding their lifestyle choices.In particular, the ‘White Paper, Healthy Lives, Healthy People: Our strategy for public health in England’ details plans for how the Government will improve public health and tackle the causes of premature mortality and illness, including obesity (DH, 2010). In addition, clinical guidelines have been developed to facilitate the prevention and management of obesity in both adults and children (NICE, 2006). Nevertheless, the battle against the obesity epidemic will be dependent on whether these policies and guidelines are effectively implemented (Poobalan, Aucott, Ahmed, Cairns, & Smith, 2010).