Even though there are 21 species of walnut trees, the nuts you’ll find in your grocery store are most likely Persian or common walnuts, but in America they’re often called English walnuts. Confusing matters further, the Central Asian country of Kyrgyzstan has the largest walnut-tree forests in the world.
One ounce of walnuts, or about 14 halves, has 185 calories, 4g of protein and carbs, 2g of fiber, and 18g of fat. Of those 18 fat grams, 2g are saturated, 3g are monounsaturated, and the rest are polyunsaturated.
Lightly toasted walnuts make an excellent addition to a number of dishes. Toss them in salads, add them to green beans sautéed in olive oil or sprinkle them on Greek yogurt. Alternatively, invest in some walnut oil. It’s expensive and not ideal for cooking (high temperatures degrade its flavor and nutrient profile), but it makes a great base for salad dressings.
Walnuts’ fat content makes them prone to rotting. Store shelled nuts in the freezer or fridge to improve their longevity.