Even Moderate Obesity Shortens Life Expectancy
According to new analysis of 57 studies that involved a total of nearly a million subjects, researchers have found that being obese can shorten a person’s average lifespan by two to four years, and by up to eight to ten years for the very obese.
The study was primarily done to see how body mass index, or BMI, effects mortality.
BMI is calculated by multiplying a person’s weight in pounds times 703, and dividing that sum by their height in inches squared. A BMI between 30 to 35 is considered moderately obese and a BMI of 40-50 is considered morbidly obese.
Though there is controversy of the use of measuring one’s health with BMI – for example, some weightlifters have high BMIs due to their muscle mass – it is still a useful tool for assessing the extent that fat can cause health problems.
Study participants were 46 years old, with an average BMI of 25 when the study began in 1979, and were mostly from North America and Western Europe.
During the follow-up period, which averaged eight years, mortality was found to be lowest in the men and women who maintained a BMI between 22.5 and 25. However, with every additional 5 BMI points, the mortality risk rose by 30%. The highest BMI deaths were due to cardiovascular disease, diabetes, kidney and liver disease, and even some cancers.
In presenting these findings, researchers hope that people may become more motivated to prevent weight gain or attempt to lose weight in efforts to extend their life.
