Low-income earners are more vulnerable to obesity than those in the middle or high-income brackets in South Korea, according to a study organized by the Ministry of Health and Welfare.

According to the study, 35.2 percent of the poorest half of the nation’s population was suffering from obesity in 2012, while only 30.5 percent of the country’s wealthiest half were overweight.

The study also found that more than one-third of the nation’s adult population was overweight in 2012.

According to lawmaker In Jae-keun, the health expenditures from a total of 23 obesity-related diseases totaled 12 trillion won ($11.8 billion) in South Korea.

“Obesity is a health issue but it is also a social issue,” she said. “We need to come up with measures to fight the medical condition as soon as possible.”