What's not to love about Tina Fey [1]? She's smart, successful, and everyone's dream best friend. Not only that, she knows the power of a healthy lifestyle. In honor of Tina's 44th birthday, we're looking at how she stays fit, healthy, and happy.

She doesn't stress about weight: In 2010, she told Vogue [2], "I don't weigh myself. I just go by if my clothes fit. I try not to participate too much in the incredible amount of wasted energy that women have around dealing with food. I just feel like being healthy is sort of a job requirement to be on TV, and being a writer is so much coping with fatigue and stress, and you just eat. You eat to stay awake."

She's smart about juice cleanses: While she has admitted to trying them, Tina knows they don't always do what they claim. "I don't really believe in those [cleanses] — your body's not like a purse. You're not supposed to turn it inside out and shake it," she's said [3].

She radiates self-confidence: There are too many funny quotes (and tidbits of life advice) in Tina's memoir Bossypants to count (we particularly enjoy her musings on being both "fat" and "skinny" [4]), but this simple self-confidence [5] booster is one we can get behind: "Do your thing, and don't care if they like it."