Israel Adesanya Blames Floppy Pec At UFC 253 On Weed, Doc Says I Smoke Too Much!

Israel Adesanya says his wonky pec at UFC 253 was NOT due to steroids or some sort of medical issue ... rather, the MMA star says it's simply 'cause he smokes too much weed!!!

"It might have just been unhealthy living a little bit -- like, smoking weed," the 31-year-old said on Ariel Helwani’s MMA Show this week. "That's what the doctor from the UFC said."

If you missed it ... while Adesanya picked apart Paulo Costa on Fight Island on Sept. 26, his right pectoral muscle flopped around far lower than his left one.

Viewers were concerned something might be horribly wrong ... and critics suggested it could be "juice" related.

But, Adesanya said he got everything checked out recently -- including getting an ultrasound and a mammogram -- and he claims docs told him everything was likely due to too much devil's lettuce.

"After a performance like that, I'd think I was on steroids too," Adesanya joked.

Adesanya says docs explained the disfigurement was nothing more than "a fat deposit" ... and he added he's now feeling -- and looking -- much better.

"It calmed down," Adesanya said. "Not as sensitive."

As for Adesanya's plans for weed now ... he says docs advised him to stop -- but he's laughing about that idea.