Worrisome new results from Israel hint that gains seen in life expectancy over the past 50 years are likely to be attenuated by rising obesity rates among adolescents. The data was collected from the medical database of the Israeli defense force and the national death registry.
The results were presented at the American Diabetes Association 2013 Scientific Sessions. Dr Gilad Twig Chaim Sheba Medical Center, Tel-Hashomer, Israel stressed that the analysis looked only at all deaths unrelated to military service so could not single out deaths from CVD or other causes.
But because military service is mandatory in Israel, and all conscripts must undergo a physical exam at the time of recruitment, the analysis provide a unique snapshot of the health and longevity of more than two million young men and women age 16-20 over the past 40 years.
The analysis included 2.16 million adolescent males (60%) and females, who had a mean age of 17.4 at the time of their first military medical tests and an overall prevalence of overweight and obesity of 11.7% at the time of recruitment.
The primary outcome for the study was mortality before the age of 50: this was seen in 1.21% of males and <1% of females.
Compared with mortality among conscripts whose BMIs put them in the 25th to 50th percentile, mortality for recruits in higher percentiles for BMI increased continuously up the BMI spectrum.
In men, being underweight (BMI<18.5) was associated with a 11% increase in mortality before age 50, while being overweight (BMI 25-29.9) and obese (BMI> 30) were associated with increased risks of 40% and 88%, respectively.
A similar pattern was seen in women increases of 11%, 44%, and 105% for underweight, overweight, and obese, respectively, although the relative risk ratios were not statistically significant for the underweight group.
More worrying still, even higher body-mass-index BMI levels within the “normal” range in teens were associated with midlife mortality. More interesting was the 11% increase in mortality for underweights with BMI <18.5.
The data seems to suggest that a normal BMI would be associated with longest survivals.