The law signed by Gov. Phil Bryant Monday was dubbed the "Anti-Bloomberg" bill in response to New York City Mayor Michael Bloomberg's attempts to ban large servings of sugary drinks, CNN said.
The new law in Mississippi says the state Legislature has the authority to regulate the sales and marketing of food.
"It simply is not the role of the government to micro-regulate citizens' dietary decisions," Bryant wrote about his decision. "The responsibility for one's personal health depends on individual choices about a proper diet and appropriate exercise."
Mississippi has the highest rate of obesity in the nation, CNN reported, but Bryant said recent studies indicate obesity among elementary students has dropped.