Atlas record

Walnuts

Walnuts stand out among tree nuts for their plant omega-3 fatty acid (ALA). They are easy to add to many meals, from breakfast to salads.

Basisraw, 100 g
Food groupNuts and oilseeds
Practical portion2–3 whole walnut kernels
Portion (g)20
Energy (kcal/100 g)654
Protein (g/100 g)15.2
Carbohydrate (g/100 g)13.7
Fat (g/100 g)65.2
Fibre (g/100 g)6.7
Notable nutrients
  • Omega-3 (ALA)
  • Copper
  • Manganese
  • Magnesium
StorageShelled kernels in a sealed container in the fridge; in the freezer for longer storage.
Food safetyA strong allergen; walnuts that have turned rancid or mouldy should not be eaten.

Nutrition profile

100 g of walnuts contains roughly 654 kcal, which makes them one of the most energy-dense foods in this atlas. A significant share of that fat is polyunsaturated, and among it the plant omega-3 alpha-linolenic acid (ALA) stands out. The values are approximate averages and shift with the variety and the freshness of the nuts.

Portion and use

A practical portion is 2–3 whole walnut kernels (roughly 15–20 g), or a small handful (about 30 g). They suit breakfast dishes such as yoghurt and rolled oats, salads and baked goods. Since they are energy dense, measuring out the amount in advance makes portion control easier when you are snacking.

Storage and points to watch

The polyunsaturated fats in walnuts turn rancid quickly in light, heat and oxygen. Walnuts in their shells keep longer; shelled kernels can be kept in a sealed container in the fridge, or in the freezer for longer storage. Do not eat them if the taste is bitter or paint-like. Walnuts are a strong allergen, and whole pieces can pose a choking risk for young children. Because nuts left in the open can develop mould, avoid any whose appearance or smell has changed.

Related terms: Almonds, Salmon, Magnesium

From the same atlas

First published: 2026-08-12Last reviewed: 2026-08-12Editorial status: working editionReport an error