Queen Latifah is turning 40 in March — not that she’s focused on the numbers. “To me as long as you’re young at heart, it really doesn’t matter how old you are,” Latifah tells PEOPLE. “To me, age is really how you feel on the inside.” But with time, she has learned valuable health lessons that she wishes she’d practiced earlier. “I wish I had known more about nutrition and exercise and how really good it could affect you at a younger age. Then I would have kicked it up a lot sooner,” says the Jenny Craig spokesperson, who has kept off the 20-plus pounds she shed using the weight-loss program for almost three years. Nutrition is key: “I don’t really diet. I kind of keep everything in moderation, exercise and eat right. I eat a lot of vegetables and lean meats, and I drink a whole lot of water,” Latifah says, before admitting her weakness: “Mac and cheese…I gotta have it!” Beyond her dedication to staying healthy, the star is also committed to the Haitian relief effort, co-hosting the BET Network’s “SOS Saving Ourselves — Help for Haiti” telethon with Diddy and Pharrell, airing this Friday, February 5 on BET, Centric, MTV and VH1 at 8 P.M. EST. The Procter & Gamble- and Pepsi-sponsored event will benefit charities including Wyclef Jean’s Yéle Haiti. Latifah also hopes to give on a more personal level by building orphanages, and possibly even adopting: “I would love to, but it’s going to take some time because things are in a bit of disarray down there. That is definitely something I would try to do. There are a lot of kids who are in need of a good home now, and I definitely think I can provide that.”