Walnuts are round, single-seeded stone fruits that grow from the walnut tree. They are a good source of healthful fats, protein, and fiber. They may enhance heart and bone health and help in weight management, among other benefits. Walnut trees are native to eastern North America but are now commonly grown in China, Iran, and within the United States. Walnuts are available both raw or roasted, and salted or unsalted. The combination of healthy fats, protein, and fiber in walnuts helps to increase satisfaction and fullness. This makes them more healthful as a snack, compared with chips, crackers, and other simple carbohydrate foods.

Walnuts have health benefits such as for heart health, weight management, battling gallstone disease, bone health, and epilepsy. In diet, they have a high-fat content, and so they are prone to becoming rancid. Rancid nuts are not unsafe but have a sharp flavor that people may find unpleasant. Keeping walnuts in their shells in a cool, dark, and dry place, or freezing them can improve their shelf life.

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