I'm not sure that I would describe them as "warning" signs, as such a term implies that this 1) Could have been avoided, and 2) Is something which should have been avoided.

But yes. Various bits of television when I was very young which either activated something internally or brought attention to something already unknowingly activated. Many examples come to mind, but this is the one I always think of first, and I don't think I've ever seen it mentioned before.

tinytoons.fandom.com/wiki/Cinemaniacs!

Note this paragraph from the synopsis:

"Superbabs goes after Wex by disguising herself as a television talk show host and questioning Wex. He reveals to her that he created a machine that reached out from space and through the drawing paper, grabbing a bottle of ink from the table and pouring it on the drawing that has Acme Ares on it. The talk show host then reveals herself as Superbabs to Wex, who tells her he knows her super weakness and pulls out a large carrot cake. She tries to resist at first, but gives in and eats one after another as Wex keeps giving them to her, laughing hysterically the entire time, until she is so obese she can barely move."

So...

Massive weight gain? Check. Overwhelming mobility impairment due to said massive weight gain? Check. Accompanying humiliation kink? Check.

That cartoon really stuck with me.

6'0", 233lbs, I'm pretty close to that threshold. Trying to suck in my belly is doing less and less, and it's getting really difficult to breathe when doing so. A few more pounds and it's going to be all over for that. Nowhere to hide...

I've had a belly hang developing and growing since ~205lbs.

That's pretty darn limber, and I'd wager something of a rarity for that weight! Congratulations! I'm monitoring for the day when I can't personally achieve these tasks.