With the advances in the medical industry and efforts to curb smoking it would be expected the the life expectancy in the USA would improve, yet there is a reduction in the rate of improvement in American mortality during the last 3 decades. The study suggests that the rise in obesity is to blame for slowing the rate of declines by a half a percentage point per each year and researchers estimate that the rising obesity is twice as important for mortality trends as a decline in smoking.
The National Health and Nutrition Examination Surveys as well as the NHANES data was collected and analyzed with the mortality files which included follow-up into death records was used in this study. The final sample consisted of 25,260 adults who ranged in age from 40 to 79.
Researchers calculated each individual’s lifetime maximum BMI on an individual basis, it was found that this measure was more efficient at predicting mortality as it was less susceptible to weight loss due to illness which biases the estimates of links between mortality and BMI, and it also relays the important elements of weight history that may have lasting effects on the individuals health.
A time trend of mortality was established within the data set by dating every observation as it occurred and moved forward. It was estimated that the impact of rising obesity was about twice as important as the impact of declining smoking for the mortality trends. Smoking is a big variable in mortality and American rates are improving faster that it would be otherwise because of the smoking reductions, but the rate improvements are being offset by the effects of obesity.
It is estimated by the researchers that the American mortality decline would have been at least a half percentage point faster that is was if it wasn’t for the fact that obesity had risen. According to the data collected by the researchers age specific death if rates had fallen at the BMI uncontrollable rate of 1.81% per year the life expectancy at age 40 would have risen from 37.6 years in 1988 to 41.1 in 2011. If death rates had fallen at the BMI controlled rate of 2.35% per year life expectancy at age 40 in 2011 would have risen to 42.3. This comparison suggest that the rising BMI reduced gains in life expectancy at age 40 by 0.9 years during this period.
The importance of the obesity epidemic are underscored by these results for American health and obesity, when it has this large of an impact on the national level of vital statistics it puts a huge spotlight on the great importance of stopping the rise of obesity and reversing it.
