DENVER — Anyone following the Kardashians would know what’s old is new again. Star Kim Kardashian credits her recent 50-lb. post-baby weight loss to the Atkins diet. Consumers have been picking back up on the low-carb craze for a while now. Sales of Atkins Advantage bars are up 23.3% to $122.1 million, and Atkins Advantage shakes are up 19.7% to $97.4 million for the 52 weeks ended Nov. 3, 2013, according to IRI across total U.S. multi-outlets.