"She should come work out with me!" Bertinelli told People.com. "She should remember you can't do everything in one day [and] her exercise has to be consistent. She can do this. There's no doubt in my mind."
Alley, who was once the spokeswoman for Jenny Craig, said Jenny Craig's current spokeswoman's transformation "blew my mind! She didn't just look good – she looked stunning! It was inspiring."
Bertinelli lost almost 50 pounds, slimming down from a high of 172 pounds to 123 pounds.
Alley said she is at "228 pounds, which is my highest weight ever. I was so much more disgusting than I thought!”
PHOTOS: Kirstie Alley Before and After.
After leaving her post as the Jenny Craig spokeswoman, where she famously whittled her 5’ 8’’ frame down to 145 pounds, and even donned a bikini on "Oprah," the star admits she "went a little wild." Moreover, she “fell off the wagon” without the scrutiny of her weekly weigh-ins.
But Alley is ready to get back in shape and says she even wants to sign up for a triathlon to help her get back to 140 pounds.
“I’m ready to work. I messed up along the way, but I’m not going to concentrate on that. I’m gonna go, "You know what? Get back on the horse, lose the freakin’ weight, and then just move forward!"
And Bertinelli is there to help, if Alley wants it. Bertinelli says she considers Alley "a mentor and a motivator. She's part of the reason I've come this far."