The person in the video is Chang Soon Hwang Here is the message he posted:
Thank you for such undeserved attention. I still can't believe it since it's the first time such a thing has happened to me ;; To be honest I can't say I started off normal. Even before I gained weight weight training was my hobby and I worked out consistantly. As when I started dieting I stuck to a strict diet plan and increased my exercising routine and time.
There are alot of questions on my diet plan and exercise..but there really isn't anything special.
It's just the common diet plan (chicken breast, sweet potato, low calorie fruits) regularly every meal and 4~5 hours a day. Even when my friends had fast foods, jjajangmyun, chicken, or ddukboggi I just smelled the food and ate according to my plan.
Even when I went on a bonding trip recently from my university I packed my food and stuck to my plan. Even when everyone was passed out from hangovers I got up early and went to do cardio.
Humans' bodies are extremely honest. You will gain as much as you eat and lose as much as you spend. I just used this simple rule.
Diet, anyone CAN do it. Most just DON'T.