Lower BMIs in older adults may not be as healthy as in younger adults….
Higher body mass indexes (BMIs) have been associated with an increased risk for developing many diseases and mortality. The optimal BMI is 18.5 to 24.9; this range is considered normal/healthy weight. Values over 25.0 are considered overweight and those over 30.0 are considered obese. The CDC warns that although the BMI correlates the amount of body fat, BMI does not directly measure body fat; many athletes’ and body builders’ BMIs will be elevated due to the weight of his or her muscle mass not fat.
There have been many studies that have analyzed the relationship between BMI and mortality. Most of the studies have concluded that higher BMIs have higher risks of mortality and vice versa. The previous studies evaluated participants ages 18 to 85 years with the median age being between 50 to 60 years. Researchers have evaluated participants with many different comorbidities and lifestyles.
This study was a stage two, random-effects, meta-analysis of over 197,940 individuals surveyed from 1990 to 2013 in thirty-two different studies. The participants were community-based adults aged 65 and older; reports of all-cause mortality was reported and evaluated in this study. The average follow-up period among the thirty-two studies was 12 years. This study aimed to determine the association between BMI and all-cause mortality in individuals aged 65 and older.
The main outcome of this study was to look at the BMI categories in relation to all-cause mortality. BMIs of 23.0 to 23.9 kg/m2 were used as the reference point for this study. There was a 12 percent greater risk of mortality for geriatric individuals with a BMI of 21.0 to 21.9. There was a 19 percent greater risk of mortality for individuals with a BMI of 20.0 to 20.9. The risk of all-cause mortality did begin to increase in individuals with BMIs greater than 33.0.
Winter J, MacInnis R, Wattanapenpaiboon N, et. al. BMI and all-cause mortality in older adults: a meta-analysis. Am J Clin Nutr. 2014 Mar. doi:10.3945/ajcn.113.068122.