An additional difference: Greek yogurt is generally lower in sugar. Is definitely due that Greek yogurt contains less lactose, or milk sugar, than regular yogurt. Stonyfield'& rsquo; s low-fat plain yogurt has 11.2 g of sugar vs. Stonyfield'& rsquo; s Oikos low-fat plain Greek yogurt with 5.9 g of sugar in a 6 oz serving.