For Indians the cut-off is already lower than international standards
Some more BMI bad news on Women’s Day.
A new study published in Menopause the journal of the North American Menopause Society says that standard BMI guidelines may not apply for post menopausal women as BMI is essentially a measure of the fat content in a person’s body and after menopause the body stores fat differently.
“The standard BMI cutoff of 25 for overweight and 30 for obesity might be too high for postmenopausal women because their body composition changes over time. As they age, women tend to lose bone and muscle mass, which are heavier than fat. So even if a 65-year-old woman weighs the same as she did at 25 years of age, fat accounts for a larger share of her weight. And that fat isn’t distributed in her body the way it was at age 25 years,” the study says.
Men also accumulate more visceral fat as they age, but “it’s much more dramatic in women,” given that they start out with less than men
This is a double whammy for Indian women because for Indians the BMI guidelines are already lower. Indians are categorised as obese once BMI crosses 25 and not 30 because of their body types that tend to store more abdominal fat. BMI is an estimate of body fat based on weight relative to height. It is calculated as a ratio of weight divided by height square.
“BMI was put forth by the World Health Organization as this kind of one-size-fits-all solution to quantifying someone’s body composition. I think our research is showing that’s really not the case,” said first author Hailey Banack, a postdoctoral fellow in epidemiology at the University at Buffalo, the State University of New York.
“I’m not surprised by the results,” said Gary Hunter, a professor in the human studies department at the University of Alabama, Birmingham, who has studied the age-related shift in visceral fat but was not involved with Banack’s study.
Men also accumulate more visceral fat as they age, but “it’s much more dramatic in women,” given that they start out with less than men, Hunter said. Between the ages of 25 and 65, the average woman will lose approximately 13 pounds of bone and muscle mass, while her visceral fat will nearly quadruple in size, Hunter said.
By comparison, the average man’s visceral fat will double in size between the ages of 25 and 65, he said.