Rob Kardashian is determined to lose the weight after ditching Kim Kardashian’s wedding. The reality star was reportedly too embarrassed by his hefty size to pose for pictures with his family, and instead took a direct flight from Paris back to Los Angeles last week.

Now, his trainer, Gunnar Peterson, who also works with Khloe and Kim Kardashian, said Rob is ready to take on the fitness challenge once and for all.

“I need to limit him. That kind of person, someone has to be there 24/7,” Peterson told TMZ about his plans for the 27-year-old. Peterson also said Rob will also endure an hour of high-intensity full body exercises, including cardio and resistance training.

A source tells E! News that Rob's "in a really bad place right now" over struggles with his weight.

Earlier this month, Rob began to trend on Twitter due to his weight gain. He hadn't been seen in public since January, and fans presumed it was because he was in fat camp in an effort to finally lose weight he has steadily gained since last year. He was seen May 19 at LAX heading to Paris for his older sister’s wedding celebrations.

“so I found out I was trending for being fat… thank you all it really made me day [sic],” Rob tweeted. “and to the blogs saying I went to fat camp or rehab LOL then why am I still fat u fools?? Y’all must have run out of real news. First I don’t believe in rehab or therapy or anything of that sort and second I’m a grown man and will work on myself when I choose,” he continued, before saying, “I’m aware that I’m fat that de faint a surprise to me lol and my only therapy will be in the gym anyways had to say somethingggggggggg [sic].”

Rob started gaining weight after a bad breakup with singer Rita Ora last year. But he's not the only Kardashian who has been blasted in the media because of their size. For years, Khloe also faced backlash for years due to her stature and weight. The 5-foot-10-inch reality star has since lost at least 30 pounds by working out and eating healthier.