The ‘Overweight’ Are Not Risking Their Lives

The body mass index (BMI) has for a long time been the standard measurement used to determine whether someone’s weight is “healthy” or not. A BMI of 25 or more is generally regarded as “unhealthy.” (BMI is calculated by dividing weight in kg by the square of someone’s height in meters.)

The suggestion is that there are somehow mortal dangers from having a BMI in this range. However, good, hard measures of health (like risk of death) show that individuals who are labeled “overweight” according to the BMI enjoy at least as good health, if not better, than those traditionally labeled as “healthy” (that is, having a BMI of 18.5 to 24.9).

The largest body of evidence regarding the non-hazards of being overweight come from the United States. Do they translate to other parts of the world?

In a study published recently in the International Journal of Epidemiology, the association between BMI and overall risk of death was assessed in a group of almost 76,000 individuals from a rural Indian population (Kerala state, South India). These individuals were monitored over nearly a decade.

Here are the results for men, using a body-mass index of 18.5 to 22.9 as a reference point:

BMI of less than 16: Risk of mortality increased by 26 percent
BMI 16 to 18.4: No statistically significant relationship with risk of death
BMI 23.0 to 24.9: No statistically significant relationship with risk of death
BMI 25 to 27.4: No statistically significant relationship with risk of death
BMI greater than 27.5: No statistically significant relationship with risk of death

Results for women were similar.

Low body weight is associated with an increased risk of death. But, here again, it seems that being “overweight” does not put individuals at heightened risk of death.

Better measures of health status and risk of death appear to be waist circumference and the waist-to-hip ratio.

References:

Sauvaget C, et al. Body mass index, weight change, and mortality risk in a prospective study in India. International Journal of Epidemiology 2008 37: 990–1004
Dr. John Briffa is a London-based physician and author with an interest in nutrition and natural medicine.
Dr. Briffa's Web site

Last Updated
Nov 13, 2008