Kefir, a fermented milk product, is a great source of protein, vitamins, and minerals, per Livestrong. Interestingly, kefir is made the same way as yogurt: Milk combines with bacteria and is allowed to ferment. The main difference is that more and different types of bacteria and yeast are used to create kefir, which has a tangy taste and a texture similar to pourable yogurt.
A serving of this dairy product packs a serious protein punch. Livestrong notes one cup of kefir has 11 to 14 grams of complete protein. It’s also a good source of calcium and vitamin D.