The percentage of seriously obese Koreans has nearly doubled in the last 12 years, the government said in a report Wednesday, attributing the problem mainly to Westernized eating habits.

The Ministry of Health and Welfare said the rate of very obese people in the overall population jumped from 2.4 percent in 1998 to 4.2 percent in 2010. By gender, the proportion of extremely obese men surged to 3.7 percent from 1.7 percent, while the obesity rate in women increased to 4.6 percent from 3 percent in the same period.

The report also revealed an increase in underweight Koreans, particularly young women. The proportion of underweight women between the ages of 20 and 40 grew sharply because of dieting, researchers said.

In 2010, the proportion of underweight women in the three age groups ― 20s, 30s and 40s ― surged to 17.8 percent, 8.3 percent and 3.4 percent, respectively. Meanwhile, the proportion of underweight men in most age groups fell in the same year.

“Underweight people are more likely to develop osteoporosis and other symptoms resulting from unbalanced nutrition,” said Oh Sang-woo, a professor at Dongguk University, who led the survey.

The ministry will hold a nationwide campaign to raise public awareness about obesity and the importance of a balanced diet starting this week, officials said.

By Cho Chung-un (christory@heraldcorp.com)