 In comparison to cow's milk, oat milk is similar in total calories per liquid volume (per cup serving, 120 vs 149 calories for cow's milk), has half the protein content, somewhat less total fat, but only about 10% of the saturated fat content, and about 1.5 times the total carbohydrate (although simple sugars are half that of cow's milk).Cow's milk has no fiber, but oat milk has 2 g dietary fiber per serving.Calcium and potassium contents are comparable, although oat milk – as for all plant-based milks – may be fortified with specific nutrients during manufacturing.