Let's take that back a step.
If we're talking about "disease" in the sense of "a condition that interferes too much with normal life absent some intervention" and not "caused by bacteria or viruses", then we already have a bunch of subjective terms in there. And I don't think you can get a reasonable definition that DOESN'T have some subjective terms.
Given that we're talking subjective terms, you're stating something like "If you have a condition that makes you suffer more than most others in certain circumstances, and this condition can be treated with pharmaceuticals, I'm fine with that, but I don't want to call that condition a 'disease'." Others might say "drugs can make your life easier, but I don't believe that you actually suffer more than others in those circumstances, you just don't handle that suffering as well". With current technology we have no means to distinguish the two.
And I almost certainly agree with your statement regarding certain circumstances. There are people that have medical conditions that make them overweight - likely including some conditions we've not identified yet. There are also people (such as myself) that just value eating over losing weight. I know of no way to know which is which for most cases, but for situations such as mine I'd not call it a condition or a disease, I'd call it overeating. All of which is to say I think I know where you are coming from.
But I lack the basis to say when other people are suffering more than I do under the same stimuli. I have no way to know if something is a disease/condition unless I've experienced it. Any more than I know if Bill Cosby raped anyone, or if the convicted murderers sentenced this year actually killed anyone.
So I extend some trust in the collective people (while at the same time thinking some large collections of people are idiots, say, politically).
Honest, non-trolling question: On what basis do you have your confidence that this is not a disease/condition?