I personally think that overeating is an addiction, not a moral failing, and is often the side effect of other mental illnesses.

I don't do this as much as others, but as someone who has suffered from Major Depressive Disorder [1], it can be really easy to eat your feelings away. When I've had really bad depressive episodes, I don't want to cook, I don't want a fucking salad, I mostly just want to feel bad about myself and I end up getting a huge meal at Taco Bell and sadly eating that. Doing that one day isn't that bad. Even doing that two days isn't that bad, but when you have a long extended depressive episode, it can easily become a pattern of weeks where you're getting unhealthy fast food every day.

I know a lot of people act like depression is a moral failing as well [2], but I personally don't think that, and it feels like obesity can be a symptom of major depression. If you ever watch "My 600lb Life", you'll see that a lot of the people on there are really going through serious mental disorders and/or dealing from PTSD from sexual abuse, and the overeating can come as a result from that.

I guess I just feel like it's reductive to say "they did this to themselves". The human brain and human psychology are complicated and irritating.

[1] Fortunately my current set of meds has really helped...medical science is pretty cool sometimes!

[2] Not saying that you said that, to be clear.