Danski znanstveniki so izvedli raziskavo, v kateri so na prebivalcih Kopenhagna ugotavljali, ali se je vrednost indeksa telesne mase, ki je v splošni populaciji povezana z najmanjšo umrljivostjo, v zadnjih treh desetletjih kaj spremila. S primerjavo podatkov za obdobji 1976-1978 in 2003-2013 so zaznali povečanje indeksa telesne mase s 24 na 27 – za 3,3 točke. Kaj je vzrok te spremembe, še ni pojasnjeno, zato tudi odgovor na vprašanje, ali je dobro, če imamo v zrelih letih malo več kilogramov, ni nujno pritrdilen!
Komentar študije Change in Body Mass Index Associated With Lowest Mortality in Denmark, 1976-2013, objavljene v JAMA The Journal of the American Medical Association, lahko preberete tudi na spletni strani Scientific Americana:
The results echo those of several other large studies that have found that being slightly overweight appears to be protective—especially after middle age. Still, there is no way of concluding that increased weight per se is the protective factor. As with any epidemiological study, even one that is as well-designed as this one, correlation does not prove causation.
“This question has been around for at least 40 years,” says David Allison, an obesity researcher at the University of Alabama at Birmingham (UAB), who was not part of the research. The late Reuben Andres, the first clinical director of the National Institute on Aging in the U.S., brought it up in the 1980s. Katherine Flegal at the National Center for Health Statistics demonstrated the trend in national data in 2005 and international data in 2013. At this point, “it’s almost indisputable that the correlation exists,” Allison says. “What is disputable is what the correlation means.”
… Perhaps, for some people, a little bit of extra weight is protective; for others it isn’t—and researchers really can’t explain why. “These epidemiological studies do not give us an answer,” says Tapan Mehta, a biostatisticianat the UAB, who was not part of the study. “They give us interesting questions to go after.”
And for those of us who want answers now? “What the data clearly show across most ethnicities and races—if you are extremely obese, having treatment will be beneficial,” Mehta says. As for those with just a few extra pounds, it never hurts to eat more fruits and vegetables, get more sleep and exercise and stay tuned.