- Waist-to-hip ratio is a better predictor of BMI, according to research presented at the European Association for the Study of Diabetes (EASD), Stockholm, Sweden.
- BMI cannot reliably predict risk of disease or death in the same way that waist-hip ratio does, since it cannot take into account where body fat is stored.
- Having high levels of belly fat is actually linked to an increased risk of heart disease and type 2 diabetes.
The waist-hip ratio (WHR) should be used to predict premature death body mass index (BMI)According to research by an Irish and Canadian presented at the European Association for the Study of Diabetes.
BMI has long been used to assess a person’s weight, with BMI 18.5-24.9 being a healthy weight range. However, scientists believe that BMI should not be used to predict an individual’s risk of illness or death because it does not take into account where fat is stored within the body.
“BMI does not take into account fat distribution,” said Irfan Khan, a medical student at the School of Medicine and Health, University College Cork, Cork, Ireland.
“It doesn’t take into account where the fat is stored – whether it’s accumulating around the hips or the waist. As a result, BMI does not reliably predict risk of disease or mortality.”
“We wanted to see if the waist-hip ratio (WHR) or fat mass index (FMI) would more reliably predict mortality across different fat distributions.”
The researchers initially demonstrated that higher levels of fat cause an increase in mortality by analyzing data from UK Biobank participants with genes associated with a risk of being overweight or obese.
Then, measures including BMI, WHR, and FMI were applied to Biobank data of more than 25,000 Caucasian men and women whose health was tracked to their death.
The association between WHR and death from any cause was shown to increase linearly, indicating that when an individual’s WHR was at its lowest, so did the risk of early death. Then increased risk of early death along with increases in WHR.
On the other hand, people with a very high or very low BMI have an increased risk of death compared to individuals with a moderate BMI or FMI.
The association between WHR and all-cause mortality was also consistent across different fat distributions, which was not evident in BMI and FMI.
“The main determinants of BMI are that it does not take into account differences in fat distribution,” Mr. Khan continued. “This could mean that someone who has accumulated fat around their waist will have the same BMI as someone of the same age and height who stores fat around their hips, despite the health risks of belly fat.
However, WHR better reflects levels of abdominal fat, including visceral fat, which wraps around organs deep in the body and increases the risk of developing a range of conditions, including Type 2 diabetes and heart disease.
“With a WHR, the message is simply: The lower your WHR, the lower your mortality risk.”
Khan says the findings should be replicated in individuals of diverse genetic origins. However, these current results indicate that a lower WHR is better, regardless of the population studied. Instead, the optimal BMI varies depending on the population, which means that a one-size-fits-all approach does not work.
Khan concluded: “Clinical recommendations and interventions should prioritize setting healthy BMI goals rather than general BMI goals.
“A more accurate measure of healthy body shape could make a big difference to the ill health and death from type 2 diabetes, heart disease, some cancers, and many other conditions.”
This article is from an early version due to be presented in Annual meeting of the European Association for the Study of Diabetes (EASD) in Stockholm, Sweden (September 19-23).