Ricky Berens was one of the U.S. swimmers who won Gold in the four-by-200-meter freestyle relay on Tuesday.  And while his teammates like MICHAEL PHELPS and RYAN LOCHTE still had races left, that was Ricky's final Olympic event.

So he decided to celebrate all those years of training and eating healthy by going to McDonald's, and ordering a TON of crap.

Surprisingly, it's only about 3,330 calories worth of food...it looks like it should be a lot more.

He tweeted a photo beforehand . . . and after, he admitted he couldn't finish it all.