"Koli and I are dating now," Johnston toldPeople in a Tuesday report.
"Being on the show together you see the good, the bad and the ugly. We saw each other at our worse. I think it made us even closer."
Johnston, a 27-year-old from Knoxville, TN, competed on The Biggest Loser's ninth season with her mother Sherry Johnston and finished as the season's runner-up after she weighed-in at 191 pounds -- a 48.93% drop from her 374-pound starting weight -- during the show's finale in May.
Palu, a 29-year-old from Rohnert Park, CA, was eliminated from The Biggest Loser's ninth season after he fell below the penultimate weigh-in line that determined the finale's first two finalists and then lost the home viewer vote which determined whether he or Daris George would become the finale's third finalist.
However Palu still weighed-in at 188 pounds and posted a 53.35% weight-loss from his 403-pound starting weight at the finale's consolation weigh-in -- which would have ranked him above eventual champion Michael Ventrella if he had won the home viewer vote.
Johnston and Palu have been maintaining a long-distance relationship thus far, but have already discussed relocating to be closer together, according to The Biggest Loser runner-up.
"I don't think he has a desire to move to Tennessee," Johnston told People. "But I've been to San Francisco and I love it."
Ironically, it was Johnston's mother Sherry who confirmed rumors Poueu was dating fellow contestant Stephanie Anderson earlier this year.