Obesity may be killing far more people than was previously thought, new research has shown.
A study found that over a 20-year period, about 18% of deaths in the United States among people aged 40 to 85 were linked to being overweight and obese.
The figure is dramatically higher than previous estimates of about 5%.
Women appeared to be far more affected than men. More than a quarter of deaths of black women, and more than a fifth of those of white women, were related to excess weight.
In contrast, the same association was seen for just 5% of black men and 15.6% of white men.
Scientists based their findings, reported online in the American Journal of Public Health, on data from a national survey spanning the period 1986 to 2006.
Study leader Dr Ryan Masters, from Columbia University in New York, said: "Obesity has dramatically worse health consequences than some recent reports have led us to believe.
"We expect that obesity will be responsible for an increasing share of deaths in the United States and perhaps even lead to declines in US life expectancy."
Although UK obesity rates are lower than in the US, they are not far behind.
In England, the proportion of men and women classified as obese rose from 13% and 16% respectively in 1993 to 24% and 26% in 2011.