Thyroid condition has 'Rampage' doubting return to light heavyweight

During an appearance on "The MMA Hour" on Monday, Quinton "Rampage" Jackson revealed why he has not fought at light heavyweight in over two years.

The former UFC champion has a thyroid condition that is affecting his ability to keep off weight, and may have been an issue for him long before he had it properly diagnosed.

"I've been dealing with this for like a year," Jackson said, according to Marc Raimondi of MMA Fighting. "I've been keeping it kind of to myself. It kind of bummed me out. If I don't stay on top of it, I gain weight really fast.

"That's what's been going on. I've been noticing after my fights I've just been gaining more weight fast, I didn't know what was going on."

Jackson has only fought twice since May 2014.

Most recently, he defeated Satoshi Ishii in a 225-pound catchweight bout at Bellator 157. Prior to that, he defeated Fabio Maldonado at a catchweight of 215 pounds.

The 38-year-old fighter has competed at 205 pounds for the majority if his career, which included a title fight knockout of Chuck Liddell, and a successful defense against Dan Henderson.

Jackson mentioned that a change in lifestyle and diet may allow him to stay put; otherwise, he's interested in heavyweight bouts against fellow UFC veteran Matt Mitrione or MMA legend Fedor Emelianenko.

However, the Ishii fight convinced him that a permanent change in divisions would be difficult.

"I don't really want to fight the real big boys, because I noticed that I tried to pick Ishii up at the end of the fight, I was trying to go for a slam and I was like, 'This dude is too big,'" Jackson said. "He felt like he had put some bricks in his ass or something. I don't know if it's his judo background or what. I was like man, maybe I do need to take my ugly ass back down to 205."