ATLANTA – Blaming a computer software error, the government today admitted overstating the nation’s weight problem in a widely reported study last year that said obesity was about to overtake smoking as the no. 1 cause of death in America.

The study, conducted by the Centers for Disease Control, and Prevention and published last March in the Journal of the American Medical Association, said that obesity-related deaths climbed between 1990 and 2000 to 400,000 a year – an increase of 100,000.

In the journal’s latest issue, the government ran a correction, saying the increase was a more modest 65,000 deaths or so.

Donna Stroup, acting director for the CDC’s coordinating center for health promotion, attributed the mistake to a computer software error.

The original study put the number of tobacco-related deaths a year at just under 435,000, and contended more Americans could soon be dying of obesity instead of smoking if current trends persisted.

Despite the correction, the agency said the finding that obesity is a major cause of death still stands.

“The combination of diet, physical inactivity, and tobacco are all leading causes of death, causing far more than a majority of total deaths in this country in the year 2000,” Ms. Stroup said. “Regardless of the controversy, it’s clear to people these are the three underlying causes of death most important to the country.”

The errors in the study were discovered soon after it was published, as scientists inside and outside the agency began to dispute its findings. That prompted the CDC to review the study, using two independent statisticians.