Rampage Jackson Eats Like a Fatty

He's a world class athlete ... he trains every single day ... so Rampage Jackson decided to treat himself this weekend ... by chowing down like a fat kid at the Orange County Fair.

The former UFC heavyweight champ was seen carrying a block full of deep fried curly fries and a burger this weekend ... because he felt like it.

Rampage has plenty of time to work it off ... his next fight isn't until October.

Fun Fact -- The OC Fair is famous for deep frying ANYTHING ... including butter, brownies, kool-aid, bacon, cheesecake, oreos ... you get the picture.