London - Olympians can eat McDonalds for free inside the athletes village, but most try hard to avoid the temptation.
American swimmers Ricky Berens and Conor Dwyer couldn't help themselves, though, after winning gold in the men's 4x200 relay.
"It was pretty bad," Dwyer said. "A couple quarter pounders, McFlurries, fries."
Berens tweeted a picture of their feast, which included Big Macs.
"We eat so healthy all the time, so I felt pretty gross after that," Berens said.
"I still feel bad this morning," added Dwyer.