People who are classed as overweight are least likely to die from any cause, according to a study published in the JAMA medical journal.
The BMI (body mass index), which compares weight and height, is used by GPs to make recommendations about a patient’s eating and exercise habits.
The new research suggests that a BMI of 27 is the healthiest, in terms of overall risk of death. The average person in Britain has a BMI of 27, which suggests that most of us are the optimal weight.
The research, carried out at Copenhagen University Hospital, shows that the healthiest measurement has gone up by three BMI points since the 1970s.
Academics examined the BMI records of 100,000 people over three decades. They found that the BMI value associated with the lowest death rates increased from 23.7 at the beginning of the study to 27 by the end.
The study’s lead author said: ‘If this finding is confirmed in other studies, it would indicate a need to revise the WHO categories presently used to define overweight, which are based on data from before the 1990s.’
One possible explanation the authors offer for the shift is the improvement in heart disease treatments over the last 30 years, which disproportionately benefit overweight people.
The health risks of obesity have been documented time and time again, and this study does not dispute these. What it does suggest is that we have become much better at mitigating the poor outcomes of obesity-related illnesses, thereby making obesity less dangerous. It also suggests that we need to consider a less reductive model of obesity than BMI, which doesn’t take into account important indicators such as muscle mass, body fat proportion and waist measurements.
But it would be irresponsible to think we should worry less about obesity because we are better at treating its negative outcomes, rather than continuing to try and prevent these outcomes in the first place.
Research score: 2/5