Huang Tao (pseudonym), who at 220 kilograms is believed to be the heaviest man in China, was set to undergo a life-changing surgery to lose weight on Thursday, according to Chengdu Daily.

The 26-year-old from central China’s Hubei Province had been plagued by overweight throughout his childhood. Though Huang’s parents were concerned about his obesity, he could not lose weight, and weighed 100 kilograms at the age of nine.

Years later, the teen decided to try out multiple weight loss methods, and eventually lost nearly half of his weight. But unfortunately the young man rebounded and put on even more weight, after following an unhealthy diet and doing less exercise.

Huang accepted he needed to face up to his obesity this February, after accidentally falling over on a street in Chengdu, southwest China’s Sichuan Province.

After being transported to the local hospital, the young man remained in a coma for a few days. Even the simplest things like using the toilet became almost impossible.

To give Huang better treatment, the hospital designed customized medical supplies. Luckily, after rehabilitation training for more than one month, the man lost almost 50 kilograms, cutting his body weight down to 220 kilograms.

Huang was set to undergo surgery on Thursday, which coincided with World Obesity Day, an annual day that aims to raise awareness of the global obesity crisis and help people achieve and maintain a healthy weight.

“The surgeries will be divided into three stages. Thursday’s surgery will cut 80 percent of his stomach to restrain the feeling of hunger,” said Liu Yanjun, Huang’s chief doctor. Liu added that Huang’s weight was expected to fall down to 110 kilograms after the surgeries.

Huang is the first patient in China to undergo bariatric weight loss surgery.

According to Global Times, China now has the world’s largest overweight population: 10.8 percent are men and 14.9 percent, women. The World Food Program has reported that the picture is even bleaker for young people, with 23 percent of boys and 14 percent of girls under 20 already overweight or obese.