Kefir and Greek yogurt are both fermented dairy staples reached for on the same probiotic, high-protein grounds, though they get there differently.
| Nutrient | Kefir | Greek Yogurt (plain, nonfat) |
|---|---|---|
| Calories | 43 kcal | 61 kcal |
| Protein | 3.79 g | 10.3 g ✓ |
| Total Carbohydrate | 4.77 g | 3.64 g |
| Dietary Fiber | 0 g | 0 g |
| Total Sugars | 4.61 g | 3.2 g ✓ |
| Total Fat | 1.02 g | 0.37 g |
| Saturated Fat | 0.66 g | 0.11 g ✓ |
| Sodium | 40 mg | 36 mg ✓ |
Notable compounds in each
Greek Yogurt (plain, nonfat)
When to choose each
Greek yogurt wins on every directly comparable macro here — more protein, less sugar, less saturated fat — but that’s mostly a function of how it’s made: Greek yogurt is strained to remove much of the liquid whey, which concentrates protein considerably. Kefir isn’t strained, so it stays thinner and less protein-dense, but its real selling point doesn’t show up in a nutrition table at all: kefir grains typically contain a far wider diversity of probiotic bacteria and yeast strains than standard yogurt cultures. If protein density is the goal, Greek yogurt wins; if microbial diversity is the goal, kefir has the edge.
Common questions
Is kefir healthier than Greek yogurt? Not in a straightforwardly “better” sense — they’re both excellent fermented dairy foods with different strengths. Greek yogurt is more protein-dense because it’s strained; kefir typically offers a wider range of probiotic strains because of how kefir grains ferment it. Which is “better” depends on which of those two things matters more to you.
Why is Greek yogurt so much higher in protein than kefir? Straining — Greek yogurt has much of its liquid whey removed during production, which concentrates the remaining protein considerably. Kefir is drunk unstrained, so it retains more liquid and ends up with a lower protein density despite starting from a similar base of fermented milk.
Nutrition values are USDA FoodData Central approximations — see our editorial approach for how we source and verify data.