Peanuts: Nutrition, Are They Legumes, and Are Peanuts Healthy?

Peanuts are the seeds of a plant whose pods ripen underground, and despite the name they are legumes, not tree nuts. An ounce of dry-roasted peanuts has about 166 calories, 7 grams of protein and 14 grams of fat in USDA data, plus a quarter of the Daily Value for niacin. Peanuts are also one of the nine major food allergens in the United States. Below: peanut nutrition raw, roasted and boiled, why peanuts are legumes, allergy and choking facts, aflatoxin rules, and whether peanuts are healthy.

Peptide Labs does not sell peanuts or peanut products. This article is general nutrition information, not medical advice.

What are peanuts?

The peanut plant, Arachis hypogaea, does something unusual. After a flower is fertilized, a stalk called a peg grows downward and pushes the developing pod into the soil, where it matures. Plant scientists call this geocarpy, described in a 2016 study in the Plant Biotechnology Journal as the peanut’s characteristic underground fruiting. Each pod usually holds a few seeds, and those seeds are the peanuts we roast, boil, grind and press for oil.

USDA data list several market types by name, including Spanish, Valencia and Virginia peanuts. In the kitchen they differ mostly in size and how they are used, and the raw USDA entries for each type are broadly similar for calories, protein and fat.

Are peanuts legumes?

Yes. Peanuts grow in pods like peas and beans, and the USDA nutrient database files every peanut entry, raw, roasted, boiled and even peanut flour, under its Legumes and Legume Products group. Almonds, walnuts, cashews and other tree nuts sit in a separate Nut and Seed Products group. FDA draws the same line for allergen labeling: peanuts and tree nuts are two separate items on its list of major food allergens.

In the kitchen and in many diet guides, peanuts are grouped with nuts because they are eaten the same way and have a similar fat and protein profile. Both views are correct in their own context: botanically and in USDA data they are legumes, while on a snack shelf they sit next to almonds, cashews and walnuts. For allergies the distinction matters, because an allergy to peanuts is not the same diagnosis as an allergy to tree nuts. Some people have both, which is a question for an allergist.

Peanut nutrition in USDA data

The table shows USDA SR Legacy values for one ounce (28.35 grams) of peanuts prepared four ways, with the percent Daily Value (%DV) based on FDA reference values. USDA counts about 32 oil-roasted peanuts in an ounce.

A few patterns stand out. Peanuts are energy dense: in USDA data raw peanuts have 567 calories per 100 grams, most of it from fat. Roasting changes little, though raw peanuts keep more folate and copper than roasted ones in USDA figures. Boiled peanuts are lower in calories per ounce because they hold water. Salt is the variable to watch: the USDA dry-roasted entry with salt lists 116 milligrams of sodium per ounce, against 2 milligrams for the unsalted version, and the boiled salted entry lists 213 milligrams, compared with the FDA Daily Value of 2,300 milligrams.

Peanuts compared with almonds

Per ounce in USDA data, plain almonds (FDC 170567) and dry-roasted peanuts have almost the same calories and fat. Peanuts have a little more protein and far more niacin, about 25% of the Daily Value against 6%. Almonds have more fiber, magnesium and vitamin E, about 48% of the Daily Value for vitamin E against 9%. For more protein-rich plant foods, see our guides to high protein foods, lentils and chickpeas.

Are peanuts healthy?

For most people without a peanut allergy, plain peanuts are a nutrient-rich whole food: they supply plant protein, fiber, mostly unsaturated fat, niacin, manganese and copper in a small handful, as the USDA numbers show. Whether they fit your eating pattern depends on a few practical points rather than on the food being good or bad.

• Calories add up quickly. An ounce is a small amount by volume, and peanuts are easy to keep eating straight from a large bag.
• Read the coating and salt. Honey-roasted, candy-coated and heavily salted peanuts add sugar or sodium; the Nutrition Facts label shows how much.
• Allergy comes first. For someone with a peanut allergy, even small amounts can cause a serious reaction, so no nutrient profile outweighs that.
• Spreads are a separate topic. Our peanut butter guide compares labels and added oils, and our almond butter guide compares the two spreads.

Peanut allergy and the 2017 early-introduction guidelines

Peanuts are one of the nine major food allergens FDA recognizes, alongside milk, eggs, fish, crustacean shellfish, tree nuts, wheat, soybeans and sesame. Under the Food Allergen Labeling and Consumer Protection Act of 2004, packaged foods regulated by FDA must declare peanuts as an ingredient in plain language. That law’s definition of a major food allergen excludes highly refined oils, so highly refined peanut oil is handled differently on labels; anyone with an allergy should ask an allergist how to handle peanut oils.

In 2017, an expert panel sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) published addendum guidelines on introducing peanut-containing foods to infants, with the aim of peanut allergy prevention. The three groups, quoted as the panel wrote them:

1. Infants with severe eczema, egg allergy or both: the panel recommends introduction of “age-appropriate peanut-containing food as early as 4 to 6 months of age.” The guideline calls for evaluation, such as allergy testing, by a clinician before introduction for this group.
2. Infants with mild to moderate eczema: the panel suggests introduction of age-appropriate peanut-containing food “around 6 months of age, in accordance with family preferences and cultural practices.”
3. Infants without eczema or any food allergy: the panel suggests that they “have age-appropriate peanut-containing foods freely introduced in the diet, together with other solid foods, and in accordance with family preferences and cultural practices.”

The same document says other solid foods should come before peanut-containing foods, to show the baby is developmentally ready. These guidelines are written for health care providers, and this article does not tell you how or when to start: talk to your pediatrician or an allergist about your own child, especially if your baby has eczema or another food allergy. Signs of a reaction such as hives, vomiting, swelling or trouble breathing need urgent medical care.

Choking risk for young children

Whole peanuts are small, firm and round, which makes them a choking risk. The NIAID addendum states that whole nuts should not be given to children under 5 years of age. CDC also shares a USDA WIC list of choking hazards for young children that includes whole or chopped nuts and seeds and chunks or spoonfuls of nut butters such as peanut butter. Your pediatrician can explain safe textures for your child’s age.

Aflatoxin and how peanuts are regulated

Peanuts can be contaminated by aflatoxins, toxins made by certain molds that grow on crops. FDA has set an action level of 20 parts per billion of aflatoxin for peanuts and peanut products, the same figure it uses for human foods in general. At home, the practical step is simple: throw away peanuts that look moldy, discolored, shriveled or smell off, and store shelled peanuts in a cool, dry place in a sealed container.

Choosing and storing peanuts

• Unsalted, dry-roasted or raw peanuts give you the plain food; check the label for added oil, sugar and salt.
• In-shell peanuts keep longer than shelled ones because the shell shields them from air and light.
• Peanuts contain a lot of fat, so they can turn rancid; refrigerating or freezing shelled peanuts in a sealed container keeps them fresher for longer.

If you suspect peanuts upset you without a clear allergic reaction, do not self-diagnose. Our elimination diet guide explains why food testing should be supervised, and an allergist can tell an allergy apart from an intolerance. We also cover a very different crop with a misleading name in our guide to tiger nuts.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Tiger Nuts: Are Tiger Nuts Nuts? Nutrition, Flour and Uses, Peanut Butter: USDA Nutrition, Calories and What the Label Means, Almonds Benefits: USDA Nutrition per Ounce, Calories and Research.