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We outline the causes and extent of this pervasive public health issue

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What is obesity?

Obesity is a chronic disease characterised by excessively high body fat in relation to lean body tissue which can lead to adverse affects on health. Obesity is classified as having a Body Mass Index (BMI) >30. BMI is a measurement that looks at weight in relation to height. Being overweight is classified as having a BMI >25, with more body fat than is optimally healthy.

Why is being overweight or obese an issue?

Obesity is associated with a range of health problems. This includes Type 2 diabetes, cardiovascular disease and some cancers; as BMI increases so does the risk of developing these serious diseases.

As well as reducing both life quality and life expectancy, obesity also has wider implications and costs for society.  It is estimated that the cost for the UK's NHS attributable to overweight and obese patients will reach £9.7 billion by 2050, with the wider cost to society estimated to reach £49.9 billion per year (Foresight 2007).

How big is the problem?

In the UK about 62% of adults are overweight or obese (58% of women and 65% of men).1 In children,  almost a third of 10-11 year olds and over a fifth of 4-5 year olds are now overweight or obese.2

An increase in the prevalence of obesity can be seen in nearly every country,  but for England obesity has more than doubled in the last twenty five years.3

Worldwide 1.4 billion adults (20 and older) are overweight and of these, over 200 million men and nearly 300 million women are obese.4

Why are people overweight or obese?

Becoming overweight or obese is caused by an energy imbalance - consuming more calories than are expended. However the reasons for the growth in obesity are far more complex and multifaceted, including:

  • An increase in the amount of food consumed
  • An increase in the amount of energy dense food consumed
  • A decrease in physical activity- due to increased use of cars, less manual work and an increase in sedentary activities such as computer games

Changes in dietary patterns and physical activity are often due to many social and environmental factors and lack of education. This means there is no single solution to tackle all the issues.

Is the answer just eating less?

Although an overconsumption of energy will ultimately lead to weight gain - just eating less is not necessarily the answer. In fact, many people classed as overweight or obese are often also deficient in some micronutrients. Often this is due to eating more energy dense foods. These are often high in fat and sugar but are not nutrient dense and therefore do not provide positive nutrients like vitamins, minerals and fibre.

How can the issue be reversed?

Overweight, obesity and related diseases are often preventable and reversible.

To tackle the issue, both the environment and society need to be shaped to encourage healthier eating and increase the level of physical activity. To succeed, individuals, communities and businesses need to play their part.

1 Health Survey England 2011
The National Child Measurement Programme 2011/12
Public Health England 2013
World Health Organisation

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