Hudson, 31, who herself lost 80 pounds, thinks fellow Weight Wathchers' pitchwoman Simpson's diet has been a colossal joke, reported Showbizspy online.

"Jennifer is frustrated with Jess and how she's handled her weight-loss fiasco. She thinks her stab at dieting has been a colossal joke. Jen said that Jessica still looks fat despite an enormous USD 4 million incentive to lose weight," a source said.

"Jennifer has reportedly been a great support system for Jessica, calling her multiple times a day and FedEx-ing her diet diary to Jess.

Jennifer thinks Jessica has been lazy and not serious about getting fit. Jessica obviously didn't put in the work. She's written Jessica off as a total mess. Jennifer is definitely having the last laugh," added the source.