Washington: Being fat may not be all that bad – but only if you’re 70, concludes a new study.
Published in the Journal of The American Geriatrics Society, the study found that adults aged over 70 years, classified as overweight, were less likely to die over a ten-year period than adults who were in the ‘normal’ weight range.
To reach the conclusion, boffins looked at data taken over a decade among more than 9,200 Australian men and women aged between 70 and 75 at the beginning of the study, who were assessed for their health and lifestyle as part of a study into healthy aging.
Obesity and overweight are most commonly defined according to body mass index (BMI), which is calculated by dividing bodyweight (in kg) by the square of height (in metres). The World Health Organisation (WHO) defines four principal categories: underweight, normal weight, overweight, and obese.
The thresholds for these categories were primarily based on evidence from studies of morbidity and mortality risk in younger and middle-aged adults, but it remains unclear whether the overweight and obese cut-points are overly restrictive measures for predicting mortality in older people.
Beginning in 1996, the study included 4,677 men and 4,563 women. The participants were followed for ten years or until their death, whichever was sooner, and factors such as lifestyle, demographics, and health were measured.
The research uncovered that mortality risk was lowest for participants with a BMI classified as overweight, with the risk of death reduced by 13 percent compared with normal weight participants. The benefits were only seen in the overweight category not in those people who are obese.
"Concerns have been raised about encouraging apparently overweight older people to lose weight and as such the objective of our study was to examine the major unresolved question of, ‘what level of BMI is associated with the lowest mortality risk in older people?’" said lead researcher Prof. Leon Flicker, of the University of Western Australia.
"These results add evidence to the claims that the WHO BMI thresholds for overweight and obese are overly restrictive for older people. It may be timely to review the BMI classification for older adults."