Obesity could shorten the average lifespan of an entire generation of America's young people by two to five years, according to a controversial new life-expectancy analysis reported in the New England Journal of Medicine.

Life expectancy in the United States is now at a high of 77.6 years. If the predictions of the researchers hold true, in a half centure we would see the first reversal in American life expectancy since the government started keeping track in 1900.

Obesity researcher David Ludwig of Children's Hospital Boston and epidemiologist S. Jay Olshansky of the University of Illinois at Chicago, in their analysis, conclude that obesity now reduces average life expectancy by some 4 to 9 months.

They conclude that if the current epidemic of child and adolescent obesity continues unabated, life expectancy could be shortened by two to five years in the coming decades.

"Childhood obesity is like a massive tsunami headed toward the United States," said Ludwig. "The tsunami of childhood obesity has not yet hit the shore -- it takes many years for complications to develop. If the clock starts ticking at age 12 or 14, the consequences to public health are potentially disastrous -- imagine heart attack or kidney failure becoming a relatively common condition of young adulthood."

About 16 percent of juveniles today are overweight, with another 15 percent at risk of becoming too heavy, which increases their chance of developing type 2 diabetes, high blood pressure and high cholesterol.

Other sources: Medical Week staff