Prepared by
Last updated
Sources
2 primary
Data
USDA FDC 2400949 and 170904

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Key differences

  • Skyr provides more protein per calorie: 18.8 g per 100 kcal, versus 8.8 g for kefir.
  • Kefir has fewer calories: 43 kcal per 100 g, versus 60 for skyr, so the same calories come with more grams of food.
  • Neither provides any fiber.

Comparison per 100 g and per serving

Values per 100 g (3.5 oz) and per typical serving. USDA descriptions: Skyr, plain, nonfat; Kefir, low-fat, plain.
NutrientSkyrserving: 150 g (5.5 oz)Kefirserving: 200 g (7 oz)Difference
Calories60 kcal per 100 g (3.5 oz)90 kcal per serving43 kcal (more favorable to satiety) per 100 g (3.5 oz)86 kcal per serving−17 kcal per 100 g (3.5 oz)−4 kcal per serving
Protein11.3 g per 100 g (3.5 oz)17 g (more favorable to satiety) per serving3.8 g per 100 g (3.5 oz)7.6 g per serving−7.5 g per 100 g (3.5 oz)−9.4 g per serving
Carbohydrates4 g per 100 g (3.5 oz)6 g per serving4.8 g per 100 g (3.5 oz)9.5 g per serving+0.8 g per 100 g (3.5 oz)+3.5 g per serving
of which sugars3.3 g per 100 g (3.5 oz)5 g per serving4.6 g per 100 g (3.5 oz)9.2 g per serving+1.3 g per 100 g (3.5 oz)+4.2 g per serving
Fiber0 g per 100 g (3.5 oz)0 g per serving0 g per 100 g (3.5 oz)0 g per serving0 g per 100 g (3.5 oz)0 g per serving
Fat0 g per 100 g (3.5 oz)0 g per serving1 g per 100 g (3.5 oz)2 g per serving+1 g per 100 g (3.5 oz)+2 g per serving
of which saturated0 g per 100 g (3.5 oz)0 g per serving0.7 g per 100 g (3.5 oz)1.3 g per serving+0.7 g per 100 g (3.5 oz)+1.3 g per serving
Waterno data per 100 g (3.5 oz)no data per serving89.7 g per 100 g (3.5 oz)179.4 g per serving— per 100 g (3.5 oz)— per serving
Protein per 100 kcal18.8 g (more favorable to satiety)8.8 g−10 g
Estimated satiety (1 to 5)5 / 5 (more favorable to satiety)4 / 5−1

In bold, the value more favorable to satiety when the gap is clear. Difference: Kefir minus Skyr. Source: USDA FDC 2400949 and 170904.

Per typical serving

With typical servings, 150 g (5.5 oz) of skyr has about 90 kcal and 17 g of protein, and 200 g (7 oz) of kefir about 86 kcal and 7.6 g.

The typical serving is a common amount used for the math, not a recommendation. Ounces are rounded US equivalents; the values come from the database entries cited in the sources.

Which is more filling?

By our estimate, skyr is more filling per calorie than kefir: 5 versus 4 out of 5.

  • Skyr: Our rule adds points for low energy density, for protein and fiber per 100 kcal, and for water in solid foods, and subtracts points for drinks with calories.
  • Kefir: Calculation: 1 (base) + 2 (very low energy density: 43 kcal/100 g) + 2 (protein: 8.8 g/100 kcal) + 0 (fiber: 0.0 g/100 kcal) − 1 (liquid, less filling than a solid; 4.6 g of sugars, under 8) = 4.

The 1 to 5 score is our own estimate: it starts at 1 point, adds points for low energy density, for protein and fiber per 100 kcal, and for the water in solid foods, and subtracts points for drinks with calories. It is useful for comparing foods with each other; it is not a measurement in people.

When to choose each one

Skyr

  • If you want more protein per calorie: 18.8 g per 100 kcal.
  • If you want more protein in a typical serving: 17 g in 150 g (5.5 oz).
  • If you eat very little: it carries our “Nutritious in small servings” tag.

Kefir

  • If you want to eat more grams for the same calories: 43 kcal per 100 g.

On a GLP-1 medication

Skyr. “High in protein”: plenty of protein per calorie; protein helps preserve muscle mass when you eat less. “Easy to digest”: a soft or low-fat food that many people tolerate well when they feel nauseous or get full quickly. “Nutritious in small servings”: a lot of nutrition in a small volume, which is practical when you eat little. “Low energy density”: plenty of volume for few calories; make sure it does not push protein foods off your plate.

Kefir. “Easy to digest”: a soft or low-fat food that many people tolerate well when they feel nauseous or get full quickly. “Low energy density”: plenty of volume for few calories; make sure it does not push protein foods off your plate. “Hydrating”: a lot of water, which contributes to hydration when you eat and drink less.

These are general guidelines, not medical advice: everyone tolerates foods differently.

Full food pages

  • Skyr: every nutrient, frequently asked questions, and similar foods.
  • Kefir: every nutrient, frequently asked questions, and similar foods.

Other comparisons

See all comparisons

Sources

Sources for the data on this page, with the access date.

  1. U.S. Department of Agriculture, Agricultural Research Service.USDA FoodData Central (Branded Foods): Plain Icelandic skyr strained nonfat yogurt, plain (FDC ID 2400949).accessed .
  2. U.S. Department of Agriculture, Agricultural Research Service.USDA FoodData Central: Kefir, lowfat, plain, LIFEWAY (FDC ID 170904).accessed .