On the September 3 broadcast of MBC's 'I Live Alone', actor Lee Jang Woo greeted viewers once again approximately 100 days after promising that he would lose weight!

Earlier this year, Lee Jang Woo shocked netizens with his weight gain on 'I Live Alone', earning the nickname "dugong" after the large sea mammal. But after deciding that his weight gain and his lavish eating habits were affecting his health, Lee Jang Woo promised viewers as well as the cast members of 'I Live Alone' that he would go on a 100-day hormone diet and exercise challenge.

And now, 100 days later, Lee Jang Woo has returned as a different man!

The actor revealed that he first started out at 98 kg, with 31~32% body fat. Now, he is at 73 kg, losing a total of 25 whole kg!

All of the 'I Live Alone' cast members were completely shocked at Lee Jang Woo's transformation, as Jun Hyun Moo commented, "You look like Matt Damon!" Kian84 also observed from a distance, "Somehow, it's hard to approach you now. When you were rounder, I felt so comfortable around you. But now you seem so distant."

Meanwhile, on this episode of 'I Live Alone', Lee Jang Woo decided to commemorate his weight loss success with a body profile photoshoot.