"Going Greek" is all the rage in the yogurt arena right now, but could kefir be the next big thing? Kefir is a cultured milk drink that's thick and tangy (sort of like a drinkable yogurt) — and like other dairy products, it crams a lot of good nutrition into a small package. One cup of plain, nonfat kefir (90 calories) provides 11 grams of high-quality protein, along with 30 percent of the daily value for calcium and a blast of tummy-friendly probiotics. Plus, it's low in lactose, which means it's generally a safe dairy option for people with lactose intolerance. Flavored varieties like strawberry, blueberry, and peach are delicious but contain added sugar, so just make sure you account for the extra calories. You can enjoy a glass of kefir straight-up, add it to fruit smoothies, or use as a substitute for buttermilk in recipes. Companies have even started making frozen kefir — a yummy, ice-cream-like treat.