Millions deemed to be overweight may be at lower risk of early death
MILLIONS of people classed as being overweight have a lower risk of death than those who are deemed to be healthy, a new study suggests.
The definition of "overweight" may need to change after research showed that the healthiest size has increased by 3.3 Body Mass Index (BMI) points since the 1970s.
People who have a BMI of 27 - officially classed as overweight - now have the lowest risk of dying from any condition.
Crucially, the average BMI for a man in the British Isles is 27 and for a woman is 26.9, meaning large numbers of people who are currently classed as overweight, actually have the optimal BMI and the lowest chance of death.
In contrast, those deemed healthy could be at greater risk than they think.
"The study is important because, compared with the 1970s, today's overweight individuals have lower mortality than so-called normal weight individuals," said Dr Borge Nordestgaard, chief physician in clinical biochemistry at Copenhagen University Hospital.
"Therefore, these results would indicate a need to revise the categories used to define overweight, which are based on data from before the 1990s. Maybe moderately overweight people need not be quite as worried about their weight as before."
Body Mass Index is based on a person's weight and height. Under the classification system, a BMI below 18.5 is regarded as underweight; anything between 18.5 and 24.9 is "healthy"; 25 or over is "overweight"; and 30 or more is categorised as "obese".
But critics say the system can overestimate the danger posed to people with heavy bone structures, or large muscle mass, while missing "apple-shaped" people who carry dangerous levels of fat around their middle.
Muscle weighs more than fat, so BMI will inevitably class muscled, athletic people as fatter than they really are.
A 6ft Olympic 100m sprinter weighing 200lbs may have the same BMI (26) as a couch potato of the same height and weight.
Last year a study by Oxford Brookes University found that simply measuring height with string, folding it in half and checking if it can fit comfortably round the waist is a better way of finding if someone has too much body fat.
The new research looked at how death rates had changed among more than 120,000 people of differing weights who were involved in studies in the 1970s, 1990s, and the 2000s. (© Daily Telegraph, London)