Trends in American eating habits come and go, but one thing remains constant: a collective sweet tooth. For more than a century Mars has been sating those cravings with an assortment of what are now billion-dollar brands known to 8-year-olds and octogenarians alike: M&M’s, Snickers, and the namesake Mars. The tasty tally: $33 billion in annual sales, and the family-owned company is looking to keep growing. It is spending $100 million to expand a Kansas chocolate factory and scooped up Mexican chocolate maker Grupo Turin. Responding to desires for purity even in sugary treats, Mars has vowed to remove artificial colors from its products.