Heinz, the processed food giant, bought Weight Watchers in 1978 for $72 million. Unilever, which sells Klondike bars and Ben & Jerry’s ice cream, paid $2.3 billion for SlimFast in 2000. Nestle, which makes chocolate bars and Hot Pockets, purchased Jenny Craig in 2006 for $600 million. And in 2010 the private equity firm that owns Cinnabon and Carvel ice cream purchased Atkins Nutritionals, the company that sells low-carb bars, shakes and snacks. Most of these diet brands were later sold to other parent companies.