A new report by Seoul's Dongguk University shows that the number of Koreans who are seriously obese nearly doubled from 2001 to 2010.

Despite the steady rise in obesity, the university report also showed a dramatic increase in the number of clinically underweight women in their 20s, accounting for nearly one-fifth of the underweight population in the country.

Overall, the percentage of the population estimated to be extremely obese was reported to be 4.2 percent in 2010, with women leading both underweight and obesity rates.

Those diagnosed with obesity often suffer from diabetes, hypertension and chronic depression. Meanwhile, many of those who are considered dangerously underweight are affected by osteoporosis and infertility.

Doctors say any sharp reduction in diet is harmful to your health and only produces short-term results. For safe, long-term management of a healthy weight, people are advised to eat in moderation and exercise regularly.