The popular VH1 hit show Celebrity Fit Club is back on our screens for a 7th season, debuting on Monday night.

PHOTOS: Check Out Before And After Pictures Of The Contestants

Fighting the flab this season are Kevin Federline and his ex-girlfriend and baby momma Shar Jackson, ex-Skid Row front man Sebastian Bach, R & B bad boy Bobby Brown, Bad Girls Club star Tanisha Thomas, Project Runway Season 1 winner Jay McCarroll, High School Musical‘s KayCee Stroh and ex-Baywatch babe Nicole Eggert.

PHOTOS: Chaz Bono Gains Back The Weight

Split into two competing teams of four, each week the teams are given different physical challenges, and weighed to see if they reached their target goal weights. They are monitored and supervised by a team that includes a nutritionist, a psychologist, and a physical trainer.

PHOTOS: K-Fed’s Weight Fluctuations

Judging by the after pictures released by VH1 the contestants worked hard to shed the pounds. But now comes the really difficult part – keeping it off!