The two boybands are going head-to-head in the UK singles chart this week. JLS are on course to score their fifth number one, ending The Wanted's two-week chart reign with current hit 'Glad You Came'.
"JLS say they can drink, but they can't," singer Max George told the Daily Star. "Give them four glasses of champagne and all they do is take their tops off and start prancing around having a dance-off. It's true. Maybe it's an insecurity about how long they will last."
His bandmate Tom Parker quipped: "They are gym bunnies. They have no body fat. There is nothing there."
The Wanted went on to say that they got "hammered" while celebrating their chart success with new X Factor judge Tulisa Contostavlos and her N-Dubz bandmates.
"They were all in good spirits," George said. "Dappy was throwing whisky down our necks and sambuca. It was a fun night."
Meanwhile, George, engaged to Coronation Street actress Michelle Keegan, claimed that he is glad that The Wanted did not come from a reality TV show.
"We are glad we are not an X Factor band. One Direction, where are they now?" he said. "It's nice that we are a band who started with nothing. The X Factor is just for that moment and we did not want to be trapped."
> JLS tell critics: 'Auto tune is part of music'
> The Wanted announce first UK arena tour
Watch JLS' video for 'She Makes Me Wanna' below: