This guy means well but he doesn't realize that she won't change. She never accepted responsibility for any of her problems in life, or even responsibility for the wrong she has done to other people.
It's funny though, in this video she says that she's an "adult" and doing mukbangs are her choice. So does that mean it's her choice that she overeats and lays around all day? I mean if she's an adult and can make her own choices, it seems like she could choose to not go to the cheesecake factory and eat a 1600 calorie meal in one sitting. You can tell she feels so offended that he even suggested it's a bad idea and that the criticism is warranted.
If skinny people can eat a lot sometimes that means it's all purely genetic since it doesn't automatically make them obese. I mean she's tried to eat like a skinny person for a day and didn't lose 500 pounds, so therefore, she's just gotta be this weight forever because it's genetics. Her childish mindset makes a day or two seem like a week. She has no grasp of how long things actually take.
She tries to act like she has literally no control in this, and I genuinely believe she knows that she does. She just wants people to stop telling her that she's not perfect and that she has a serious problem that she's fully capable of fixing. It makes her feel responsible for the bad things she's done and bad choices she makes. It makes her uncomfortable like a 12 year old first starting to gain self awareness and feeling guilt on their own after being an asshole.
The problem is that she is nearly 30 and still has this mentality. She is mentally a spoiled 14 year old. Her growth and life have been stagnant. Amber has been doing the same things as long as she's been online. She has no grasp of time, lacks self awareness, will power, and the ability to accept responsibility. She won't change because she doesn't even believe she's that fat and doesn't think she can be wrong, plus she's not going to give up the only pleasure in her life.