Supersize Me is not a new film - but definitely one that's worth your time. Having been nominated for an Academy Award for Best Documentary in 2004, and winning awards at the Sundance Film Festival as well as from the International Press Academy and the Writers' Guild of America, its reputation for quality is well established.
How does it help simplify your life? By helping you avoid fast food, which is bad on your budget and on your body. The film encourages an appreciation of the simple ideas of cooking at home, of knowing what you're actually eating, and of understanding how the nutritional value of your food impacts the quality of your life.
Get the DVD, used, for under ten bucks at amazon.com. Or better yet, rent it for free at your local library. (The San Antonio Public Library alone has 20 copies on its shelf.)