system
A chat on subreddit /r/NoStupidQuestions
human
What kind of passive / aggressive  reply is that? 

You're not a magical being. If you're asking why you've been obese your entire life, the answer is because you've eaten far more calories than burned everyday.
gpt
Literally someone said to see a doctor and OP asked what they would do. The first thing they would tell OP is exactly what this comment says. 

Maybe they’re looking to know if it’s mental illness or something to have an excuse, idk.