Diet A&W is now A&W Zero Sugar! Treat yourself to a deliciously refreshing American Classic with A&W Zero Sugar Root Beer, made with the same rich and flavorful taste as Diet. It has zero calories, plus it's caffeine free. It is the perfect special treat to have at your next family night. A&W has become the standard in root beer soft drinks, and it's best when enjoyed in an ice-cold mug or with vanilla ice cream for a delicious root beer float that the entire family can enjoy. Make your day or family night a little bit sweeter with the rich and flavorful taste of A&W Root Beer Zero Sugar.