The reality TV matriarch is said to be upset her son has put on weight recently, now weighing a reported 260lb, and has asked him to lose weight, so he is considering getting his stomach stapled.
A source said: ''Rob hates gyms and working out. But he's under strict orders to lose 70lbs before [his sister] Kim's wedding to Kanye West this summer.
''Rob figures that getting his stomach stapled is the only way to meet Kris' deadline.''
Rob is thought to have turned to food after his split from singer Rita Ora - who is now dating the world's highest paid DJ, Calvin Harris - in 2012.
The insider added to National Enquirer magazine: ''Rita totally ripped Rob's heart out. [She] destroyed him, and he turned to comfort eating and beer.''
While he wants to slim down again Rob is said to be wary of stomach stapling, as ''the procedure is a major operation'' and must be carefully considered and weighed out before he commits.