Obesity and the impact of weight on health

The rising tide of obesity

Approximately 65% of adults in the UK are either overweight or obese as defined by traditional BMI criteria (see Definition of Terms, below). In 1980 just 6% of men and 8% of women were defined as obese; by 2010 the number is predicted to rise to 25% of men and 28% of women.

In 2003, the Economist front cover depicted "The shape of things to come". In 2009, the obesity epidemic has now well and truly arrived in the developed world and continues to accelerate at an alarming pace.

The Foresight report, published in 2008, makes the prediction that by 2050 - in just one generation's time - nine out of ten adults in the United Kingdom will be either overweight or obese.¹

The impact of weight on health

Obesity is associated with some of the most prevalent diseases of modern society. Excess weight puts people at risk of developing heart disease, type 2 diabetes, high blood pressure and some forms of cancer.

A rise in the following important medical conditions is anticipated over the next decade or so as a direct result of the rising tide of obesity:

Type 2 diabetes

The greatest risk of obesity is the development of type 2 diabetes. The prevalence of type 2 diabetes is raised at even modest levels of overweight: it is doubled at a BMI of 25kg/m² compared with 21kg/m². It is ten-fold higher at a BMI of 30kg/m²; above a BMI of 35 kg/m², it is 42-fold higher in men and 93-fold higher in women.

It is estimated that half of all cases of type 2 diabetes would be eliminated if weight gain could be prevented.

Obesity and heart disease

A large multinational study (INTERHEART) found the presence of abdominal obesity was as important as smoking as a risk factor contributing to heart attack in Western populations.²

In another large study involving women, the risk of coronary heart disease was found to increase two-fold in women with a BMI of between 25 and 28.9kg/m². For those with a BMI of 29kg/m² or more, the risk was 3.6 times greater.³

For more information about cardiovascular disease, see the Vascular screening page on this site.

Obesity and cancer

The risk of certain cancers, particularly colorectal cancer, rises with increasing weight. The relative risk of all cancers, as depicted below, is increased by half in those with a BMI greater than 40kg/m².

The impact of weight on the health economy

The 2003 Economist cover "The shape of things to come" was a stark reminder of the health economic impact of obesity. The year following publication of this issue of the Economist came another warning, this time from the House of Commons Select Committee Report on Obesity (2004):

"[Obesity] will bring levels of sickness that will put enormous strains on the health service, perhaps even making a publicly funded health service unsustainable."

The above sentiment was re-iterated in 2007 by Derek Wanless, who originally led the House of Common Select Committee on Obesity three years earlier.

In 2008, a team of scientists published their prediction of the impact of the obesity epidemic, looking ahead to 2050.

The Foresight team report¹ estimated the total cost of obesity to the NHS and the wider economy to be 50 billion pounds per year by 2050. To put this into context, the entire NHS budget presently stands at 70 billion pounds per year, encompassing the treatment of all chronic conditions, funding all GP consultations and acute hospital admissions.

NHS costs in dealing with overweight and obesity alone is conservatively expected to rise from 4.2 billion to 9.7 billion pounds per year by 2050. This represents an increase from 6% to 13.9% of the present NHS budget.

Definition of terms

Body mass index

Body mass index measures a person's weight in relation to their height. The equation to calculate body mass index is:

Weight (in kilograms) / Height (in metres)²

If a person weighs 60 kilograms and is 1.6 metres tall their body mass index is:

60/1.6² =

60/2.56 = a body mass index of 23 kg/m²

References