Earlier this summer, Goldman Sachs and the Swiss bank UBS downgraded the stock rating for the food company General Mills from "buy" to "neutral."
One of the main reasons? Greek yogurt — the growing popularity of the thick and tangy dairy product is changing consumer tastes and the yogurt industry.
Hamdi Ulukaya comes from a long line of dairy farmers in Turkey, and he says the first time he tried yogurt in America, he did not approve.
"I was just surprised that, there was so much sugar in there. It was so much preservatives and colors," he says.