They're still "figuring it out," he says. "I wouldn't say they are walking yet"

Credit: Bill Boatman

While his wife Mariah Carey has been photographed vacationing in Capri, Monaco and Morocco with their 13-month old twins Moroccan and Monroe, Nick Cannon stuck around to take the reins behind the camera – directing his first feature film.

But, he admits, it’s very hard being away from his family, especially now that the twins have recently taken their first steps.

“I try to not go seven days without seeing them. I’ll be with them this weekend,” Cannon, 31, tells PEOPLE from the Norwalk, Calif., movie set of School Dance, a coming-of-age comedy that he co-wrote and is also producing.

“They are taking steps and figuring it out, but I wouldn’t say they are walking yet,” he says. “I thought walking was, like, one day you stand and then you just start walking. I didn’t know it was a process. There’s a lot of falling. They take a few steps and then fall and go right back to crawling.”

So which twin will master their unassisted waddle first? It’s either’s game, says Dad. “Roc can balance himself a lot better. He can stand and bounce without falling for a long time. But Monroe takes more steps than he does.”

Happily, after battling kidney failure, blood clots and autoimmune disease, Cannon’s health is back on track. “The doctor says I am cured,” says the America’s Got Talent host.

His new diet, which required him to cut out fried and processed foods, along with proper rest and a 30-45 minute daily boxing workout, is pumping him with much needed energy – to chase his twins around the house.

Not that it’s been easy adhering to his diet. “I had some salt ‘n vinegar chips for the first time a week ago,” he admits. “I was like, ‘Man, these things have never tasted so good.’ ”

Still, he’s stayed pretty disciplined thanks to his wife, whom Cannon calls Dr. Carey. “She made sure I was eating what I was supposed to be eating, not overdoing it, resting, and following the doctors’ orders.”

Even so, there is one order he still refuses to follow. Carey wishes he’d stop boxing. “It’s still a big secret,” he says kiddingly about getting back into the ring. “Don’t tell her.”