This is the text of an article that appeared in the February 2011 edition of the Marshwood Vale Magazine.
I couldn’t help noticing the long queues in the Bridport food shops just before Christmas and they seemed symbolic of the overindulgence we are expected to practise over the holiday period. I also read in the Bournemouth Echo around the same time that about 25% of adults (over 16s) in Poole and Bournemouth are obese. In West Dorset, the situation is slightly better but still about 20% of adults are obese. How should we react to these seemingly paradoxical observations?
What is obesity?
Obesity is a clinical term referring to being seriously overweight. Obesity is characterised by the laying down of excessive amounts of fat as adipose tissue in the abdomen. An obese person will often have a waistline that is larger than expected for their height; they will be “apple shaped” rather than “pear shaped”. We can assign a number to this change in shape by calculating the Body Mass Index or BMI (see below). A BMI over 30 is defined as obese.
In Poole and Bournemouth, therefore, about a quarter of adults are obese with a BMI of 30 or greater. They are not alone as figures for many other parts of the country are similar or worse with a handful of towns in the UK having nearly one in three obese adults. Obesity is also a problem in children with about one in six of 2-15 year olds being obese. If we look around the world at the incidence of obesity, the US leads the field with nearly one in three of all adults being obese whereas countries such as France and Italy have much lower rates. Obesity rates in most countries have increased steadily over the past 30 years; for example, in 1978 only one in twenty adults in the UK was obese compared with one in four now.
What causes obesity?
Obesity is the result of taking in more calories in your diet than you are burning through physical activity. Some of these excess calories are converted to fat leading to the increase in waistline.
But why has obesity increased so much? In the past 30 years there has been some increase in how much food people eat in the UK although this is not easy to document. There have also been changes in lifestyle (increased use of motorised transport, a more sedentary lifestyle) leading to less physical activity. These changes mean that we consume more calories than we need for the physical activity we do and the result is the increase in obesity.
We also know that inherited factors are important as obesity tends to run in families and it has been shown that this is due to inherited genes. Genes alone do not cause obesity but they influence whether it occurs when food is plentiful.
Why is obesity an important issue?
Obesity has very serious effects on human health. Being obese increases the risk of suffering from cancer, heart disease, diabetes and arthritis. Obesity decreases the quality of life for individuals, it increases health care costs and it has been shown that being obese decreases life expectancy. Moderate obesity decreases life expectancy by about 3 years but being seriously obese decreases life expectancy by 10 years. The continuing increase in obesity, with its insidious effects on human health, has been described as a “ticking time bomb”.
What can be done?
There is no escaping the conclusion that obesity is the result of eating more food than we need for the physical activity we do. Reducing obesity should then be simple – eat less, exercise more. But it can’t be that easy or the problem would have been solved by now.
A government report in 2007 concluded that we now live in an “obesogenic” environment. We are confronted with an abundance of cheap, energy rich food and coupled with extensive use of motorised transport and a sedentary lifestyle this leads to obesity. The report proposed that the problem should be tackled by population level interventions which should include promoting healthy eating, physical activity, changing the way towns operate to increase walking etc.
This has lead to the “Healthy Weight, Healthy Lives” programme aimed at promoting these goals. After two years of the programme, obesity rates in children are beginning to level off but continuing to rise in other groups. This is a long term programme so we should not expect quick results but I am surprised that there is so little evidence of the programme in daily life, promoting good eating habits and promoting exercise. Food labelling is one way of making people aware of what they are eating but even here there is a lack of uniformity. Some major food retailers have adopted the traffic light system which provides a quick, clear indicator of levels of fat, sugar and salt in food. Other major food retailers have chosen instead to adopt the Guideline Daily Amount system which in my view is more complex and provides less clarity.
Locally, in Poole and Bournemouth, there is an Obesity Strategy and Action Plan which includes banning fast food outlets within a mile of schools. This is a good start but we need to see a much more aggressive promotion of healthy eating and healthy lifestyle in the UK coupled with a uniform system of food labelling. If we choose not to do this, obesity and its associated negative effects on health will become the norm.
How to calculate your BMI
Measure your weight in kilograms
Measure your height in metres (h)
Your BMI is then given by the following equation:
BMI = w/h2
You can also determine this online using the BMI healthy weight calculator on the NHS Choices web site (http://www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx).
A BMI of 25-30 is overweight
A BMI of 30-40 is obese
A BMI above 40 is very obese