Obese adolescents have the same risk of premature death in adulthood as people who smoke more than 10 cigarettes a day, according to a new study from Karolinska Institutet. What most interests the researchers is that the combination of overweight and smoking did not act synergistically as mortality risk factors.
"This means that being overweight or obese at the age of 18 increases the risk of premature death, regardless of smoking status", says Martin Neovius, at the Department of Medicine, Solna, who lead the study.
The research team analysed the cause of death of over 45,000 men who were conscripted into Swedish military service. The participants all had their body mass index (BMI) measured and reported their smoking status at the age of 18 and were followed up for an average of 38 years. In total, the authors assessed 1.7 million person-years of follow-up in relation to the health and mortality of all the participants, during which 2897 men died.
The study showed that obesity in teenagers carried the same risk as being a heavy smoker; a doubled risk for premature death was seen both in obese non-smokers and normal weight heavy smokers. Being an obese heavy smoker resulted in a five-fold risk increase.
Martin Neovius, Johan Sundström, Finn RasmussenCombined Effects of Overweight and Smoking in Late Adolescence on Subsequent Mortality: Nationwide Cohort Study
BMJ online, 25 Februari 2009