| What is obesity?
Obesity
is defined by the World Health Organisation (WHO) as “abnormal or excessive
fat accumulation that may impair health” (1). It is measured using Body
Mass Index (BMI), which is a ratio of weight to height. The formula is weight
divided by the square of the height (w/h2). A male of 5 foot 8
inches would officially be overweight at 12 stone 4 lbs (BMI 26.1). At 14
stone 8 lbs he would be obese (BMI 31).
|
underweight |
Up
to 18.49 |
| WHO
preferred range |
18.5-24.9 |
| overweight |
25 |
| almost
obese |
25-29 |
| obese
class 1 |
30-34.9 |
| obese
class 2 |
35-39.9 |
| obese
class 3 |
over
40 |
The
British NHS use the same scale (9) but in fact it is only a very rough guide.
It does not distinguish fat from muscle so athletes are often misclassified as
obese (13;43). It is particularly misleading during the rapid changes of
puberty. Body
Mass Index (BMI) as a measure of obesity is increasingly challenged as crude
and misleading (13;2.5-6). Nick Trefethen, Professor of Numerical Analysis
at Oxford University, recently proposed a new formulae to correct this
problem: 1.3 x weight, divided by height to the power 2.5 (6). Obesity is not a simple matter of overall weight. Another measurement focuses
on where the fat accumulates. It is said to be more harmful if gathered round
the waist, so ‘safety levels’ are waist measurements below 31.5 inches for
women or 37 inches for men. Obesity
is normally caused by taking in more calories than we use. However, individually,
it can result from a range of medical conditions or reaction to medications.
It can also result from eating the same amount of food of a less healthy
kind, with more fat and sugar. But it is not just a simple matter of
individual ‘choice’; changes in social habits are affecting whole
populations. Why is it a problem and who says so? It
matters because, globally, WHO claim 2.8 million people die each year “as a
result of being overweight or obese.”(1). Obesity is associated with
heart disease and stroke, diabetes, osteoarthritis and ‘some cancers’
(endometrial, breast, and colon). The UK Department of Health announced in
2013 that “In England, most people are overweight or obese. This includes
61.9% of adults and 28% of children aged between 2 and 15." They include in
the consequences of obesity harm to “self-esteem and mental health” (4) but
they are also concerned that “health problems associated with being
overweight or obese cost the NHS more than £5 billion every year.” Unhealthy
populations are expensive and the NHS has financial problems (31#3) It could be argued that a lot of
self-esteem issues arise from the way overweight people are stigmatised. An
approach to obesity that always links calories and weight with illness and
‘being a problem’ will increase pressure on them to diet to conform to an
ideal size and shape. This leads to repeated cycles of
weight loss and regain which can in themselves be harmful. It can also be argued that focusing the
problem on an individual’s responsibility to lose weight ignores wider
problems of poverty, education and food prices, moving the focus away from
our responsibility to create a fairer society where everybody can afford
healthy choices and is properly supported in making them (7,8). So we may be using ‘obesity’ as a simple shorthand for a complex
problem, making simplistic assumptions that misrepresent the problem we need
to solve. Regional differences in obesity figures
suggest that a national campaign, saying the same thing to everybody, is
fighting against stronger influences that vary by region (41p25;43). The
effectiveness of ‘healthy living’ messages sponsored by public agencies has
been questioned. What could we do about it? We
may need to think more widely about nutritional choices and life styles. WHO point out that our personal choices and
habits are influenced by a wide range of social factors and by “policies in sectors such as health,
agriculture, transport, urban planning, environment, food processing,
distribution, marketing and education.” To make healthy choices we need
“supportive environments and communities” so that the healthy choices are
“accessible, available and affordable”. Those with lower incomes might focus more on calories per £ rather
than good nutrition. Advertising encourages unhealthy choices, promoting
processed foods with too much fat, sugar and salt content and encouraging
children to make poor choices early on (1). What solutions do we
prioritise? Medical; fiscal; social and economic;
psychological; educational; physical activity? A study
in 2007 found a consensus that we needed
“mutually reinforcing measures related to education, information, healthier
food and physical activity”. So the policy options we offer you are not mutually exclusive and
may well work best when they work together. However, they all require time,
attention and money, which are finite resources, so we have to prioritise. If resources are limited, what kind of approach would you put at the
front of the queue?
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