Walnuts: what it contains and why it matters
Walnuts is a tree nut (akhrot). This page lists its nutritional content from published sources and explains which lab parameters it relates to.
Last reviewed: 2026-09-04
Nutritional content of walnuts
Per 100 g edible portion, from published composition data.
| Nutrient | Per 100 g | Source |
|---|---|---|
| Energy | 654 kcal | USDA |
| Protein | 15.2 g | USDA |
| Total lipid (fat) | 65.2 g | USDA |
| Carbohydrate, by difference | 13.7 g | USDA |
| Fiber, total dietary | 6.7 g | USDA |
| Magnesium | 158 mg | USDA |
| Potassium | 441 mg | USDA |
| Phosphorus | 346 mg | USDA |
| Calcium | 98 mg | USDA |
| Iron | 2.91 mg | USDA |
Which lab parameters does walnuts relate to?
Magnesium
Magnesium supports muscle and nerve function and helps build bone [WHO].
Understand your Magnesium result →See all magnesium-rich foods →
Potassium
Potassium helps nerves and muscles work and helps balance the body's fluids [WHO].
Protein
Dietary protein provides the amino acids the body uses to build and repair tissue [WHO].
Vegetarian and dietary notes
Walnuts are a raw plant-based food suitable for vegan and vegetarian diets, but they are tree nuts and represent a common food allergen.
Frequently asked questions
What types of fatty acids are present in walnuts?
Walnuts consist primarily of polyunsaturated fatty acids, containing approximately 9.08 g of alpha-linolenic acid (an essential plant omega-3 fatty acid) and 38.1 g of linoleic acid per 100 g [USDA].
How much protein do walnuts contain and what is its role?
Walnuts provide 15.2 g of protein per 100 g [USDA]. Dietary protein provides essential and non-essential amino acids necessary for tissue growth, enzymatic activity, and cellular maintenance.
What is the magnesium content in walnuts?
Walnuts provide 158 mg of magnesium per 100 g [USDA]. Magnesium acts as an essential cofactor in over 300 biochemical reactions in the human body, including ATP synthesis, muscle contraction, and protein synthesis.
What is the potassium concentration in walnuts?
Walnuts contain 441 mg of potassium per 100 g [USDA]. Potassium functions as a major intracellular cation required for the maintenance of osmotic pressure, cellular membrane potential, and neuromuscular conduction.
How much dietary fiber is found in walnuts?
Walnuts contain 6.7 g of total dietary fiber per 100 g [USDA], consisting of structural plant carbohydrates that pass through the upper gastrointestinal tract undigested.
Sources
- USDA — USDA FoodData Central, Agricultural Research Service. https://fdc.nal.usda.gov/
- WHO — World Health Organization — nutrition fact sheets. https://www.who.int/