Rob Kardashian Weight Loss: Trainer Gunnar Peterson Speaks Out With New Fitness Plan

Rob Kardashian is reportedly getting serious about weight loss.

After skipping sister Kim Kardashian's weekend wedding to Kanye West because of his insecurities, Rob is more determined than ever to get in shape and has enlisted the help of celebrity trainer Gunnar Peterson to help make it happen.

"Rob texted [Gunnar] when he arrived back from Italy, where he bailed on Kimye's wedding because he felt too fat to pose for family photographs," TMZ reported on May 28. "Gunnar says Rob's text was clear as crystal—he wanted to hit the ground running ... literally ... posting up workouts every day this week, and continuing the intensity until the fat is gone."

Over the weekend, Rob flew to Europe, where he was expected to partake in sister Kim's wedding festivities, as well as her May 24 wedding to Kanye. However, after reportedly feeling overwhelmed with the possibility of having to pose for photos, Rob, who hadn't been photographed since Jan. 2014 prior to his arrival to LAX, flew back to Los Angeles, arriving on Saturday evening, just as Kim was walking down the aisle in Italy.

In his chat with TMZ, Gunnar promised to show Rob "no mercy," revealing he will endure an hour of high-intensity full body exercises, cardio and resistance training each and every day.

"Rob is locked and loaded," Gunnar stated.

Prior to leaving Europe, Rob's family, including mother Kris Jenner, had attempted to show him support and encourage he remain in town, but at the end of the day, it was Rob's decision, and he didn't feel comfortable around the cameras.