LONDON, Nov 1 ― New UK research has found that an excessively low and excessively high Body Mass Index (BMI) are both linked to a higher risk of death from a variety of causes.
Led by the London School of Hygiene & Tropical Medicine, the new study is one of the largest of its kind, looking at data gathered from 3.6 million people. It investigates the association between BMI and both the risk of death overall as well as the risk of death from a wide range of different causes.
The researchers calculated the risks of death according to BMI, including deaths from conditions such as cardiovascular disease, cancer, respiratory disease, dementia and Alzheimer’s, and suicide, and adjusted for other influencing factors such as age, sex, smoking status, alcohol use, and socioeconomic status.
The findings, published in The Lancet Diabetes & Endocrinology, showed that overall, both low and high BMI were associated with an increased risk of death, with an optimal BMI of between 21-25kg/m2 associated with the lowest risk of death from the two leading causes of death, cancer and cardiovascular disease.
A BMI of 25kg/m2 was linked to the lowest risk of death from cardiovascular disease, with every 5kg/m2 increase above this associated with a 29 percent higher risk of death. For cancer, the lowest risk of death was at 21kg/m2, with every 5kg/m2 increase in BMI above this associated with a 13 percent higher risk.
Obesity, defined as a BMI of over 30kg/m2, was associated with a higher risk of death from cancer or cardiovascular disease, as well as death from several other major causes including respiratory diseases, liver disease, and diabetes.
Carrying excess weight was also associated with a 4.2-year reduction in lifespan for men, and 3.5 years for women.
Low body weight was associated with a higher risk of death from a wide range of causes including cardiovascular disease, respiratory disease, dementia and Alzheimer’s and suicide, which the team said suggests that low BMI may also be an important indicator of poorer health.
The authors noted that the study did have its limitations, such as not including information on participants’ diet or physical activity levels to see how they affected BMI.
Lead author Krishnan Bhaskaran said, “BMI is a key indicator of health. We know that BMI is linked to the risk of dying overall, but surprisingly little research has been conducted on the links to deaths from specific causes.”
“We found important associations between BMI and most causes of death examined, highlighting that body weight relative to height is linked to risk of a very wide range of conditions. Our work underlines that maintaining a BMI in the range 21-25kg/m2 is linked to the lowest risk of dying from most diseases.” ― AFP-Relaxnews
