Chestnut benefits come mainly from carbohydrate, fibre, potassium and vitamin C. Roasted European chestnuts have about 245 calories, 53 g of carbohydrate, 5.1 g of fibre and 2.2 g of fat per 100 g, or about 70 calories per ounce (28 g).
Unlike most nuts, chestnuts are low in fat and high in starch. Cooking them is the usual and recommended way to eat them.
What Are Chestnuts?
Chestnuts are the seeds of Castanea trees. People roast, boil or microwave them in winter. They taste sweet and soft once cooked.
Chestnut Benefits: Nutrition Facts Raw vs Roasted
The table uses two USDA entries for European chestnuts: raw and peeled, and roasted. Percent Daily Value (%DV) uses current FDA reference amounts.
| Per 100 g | Raw, peeled | %DV | Roasted | %DV | Roasted, 1 oz (28 g) |
|---|---|---|---|---|---|
| Calories | 196 | n/a | 245 | n/a | 70 |
| Protein | 1.6 g | n/a | 3.2 g | n/a | 0.9 g |
| Total fat | 1.3 g | 2% | 2.2 g | 3% | 0.6 g |
| Carbohydrate | 44.2 g | 16% | 53.0 g | 19% | 15.0 g |
| Total sugars | not declared | n/a | 10.6 g | n/a | 3.0 g |
| Fibre | not declared | n/a | 5.1 g | 18% | 1.5 g |
| Sodium | 2 mg | 0% | 2 mg | 0% | 0.6 mg |
| Potassium | about 494 mg | 11% | 592 mg | 13% | 168 mg |
| Vitamin C | about 39 mg | n/a | 26 mg | n/a | 7.4 mg |
The calories reconcile with the macros within about 1% on both rows. As a result, the two entries are internally consistent.
Why Chestnut Benefits Look Different Across Sources
- Raw or roasted. Roasting drives off water, so each gram of roasted chestnut carries more calories (245 vs 196 per 100 g). Roasting also lowers vitamin C, from about 39 to 26 mg per 100 g.
- Different species. USDA lists European, Chinese and other chestnuts separately. A page that mixes species mixes numbers.
- Serving units. Quarter cups, single nuts and ounces all appear online, but the weight of a quarter cup or one nut is rarely stated. Ounces and grams are the safest comparison.
- Undeclared values. The raw entry does not declare fibre or sugars. Pages that quote them for raw chestnuts are estimating or borrowing from the roasted entry.
Raw, Roasted or Boiled: What Changes
Tufts University notes that raw chestnuts are edible but bitter, because they contain tannins that can cause nausea. Cooking breaks down the tannins and brings out sweetness. Roasting, boiling and microwaving all work.
Score a shallow cross on the flat side before cooking. That stops the shells bursting. Choose nuts that are smooth, firm and heavy for their size, with no cracks or mould.
Chestnuts vs Water Chestnuts
Water chestnuts are a different plant, sold in cans and used in stir-fries. Their nutrition differs, so do not swap values between the two. Horse chestnuts, also called conkers, are not food and should not be eaten.
What the Evidence Says About Chestnut Benefits
| Claim | Where it stands | What to know |
|---|---|---|
| Chestnuts are low in fat compared with other nuts | Supported | 2.2 g per 100 g roasted, and Tufts notes they are lower in fat, protein and calories than most nuts. |
| Chestnuts supply vitamin C | Supported | 26 mg per 100 g roasted. Tufts calls them the only nut with a significant amount. |
| Chestnuts are a good fibre source | Partly supported | 5.1 g per 100 g roasted, or 18% of the Daily Value. One ounce gives about 5%. |
| Chestnuts are low-calorie and help weight loss | Not supported | 245 calories per 100 g roasted. Portion size matters, and no food causes weight loss alone. |
| Chestnuts help people with diabetes manage blood sugar | Not supported | About 53 g of carbohydrate per 100 g. Follow your care plan. |
| Chestnuts lower cholesterol or protect the heart | Not established | No trial evidence was found for chestnuts alone. |
| Chestnuts are anti-inflammatory | Not supported | No human evidence was found. |
| Raw chestnuts damage the liver and kidneys | Not supported | Raw chestnuts taste bitter and may cause nausea. No evidence of liver or kidney harm was found. |
Chestnut Safety: Raw Nuts, Allergies and Special Diets
Raw nuts. Cook chestnuts to avoid bitterness and possible nausea. Discard nuts that are mouldy, soft or smell musty.
Allergy. People with tree nut or latex allergy should ask their allergist before trying chestnuts. Read labels on chestnut purees and flours.
Diabetes. One ounce of roasted chestnuts holds about 15 g of carbohydrate. Ask your care team how to count it.
Potassium limits. People told to limit potassium should check with their care team. A 100 g portion of roasted chestnuts holds 13% of the Daily Value.
Medication. Never stop or change prescribed medicine because of a food. Talk to your prescriber first.
Chestnut Benefits FAQ
They are a nutritious, low-fat, starchy food with fibre, potassium and vitamin C. They are also high in carbohydrate, so portion size matters.
Roasted European chestnuts have about 245 calories per 100 g, or about 70 per ounce. Raw peeled chestnuts have about 196 per 100 g.
About 53 g of carbohydrate per 100 g roasted, or about 15 g per ounce. That is roughly 19% of the Daily Value per 100 g.
Raw chestnuts are edible but taste bitter, and the tannins can cause nausea. Roasting, boiling or microwaving them is the usual advice.
Yes. Roasted chestnuts have about 5.1 g of fibre per 100 g, which is 18% of the Daily Value. One ounce gives about 1.5 g.
For a nut, yes. Roasted chestnuts have about 26 mg per 100 g, and raw peeled ones have about 39 mg. Roasting lowers the amount.
No evidence shows they treat diabetes. Chestnuts hold about 15 g of carbohydrate per ounce roasted, so ask your care team how to fit them into your plan.
No single food causes weight loss. Chestnuts are lower in fat than other nuts but still hold about 245 calories per 100 g roasted. A registered dietitian can tailor advice to you.
No. They are different plants with different nutrition. Do not swap values between them, and do not eat horse chestnuts (conkers).
Related Reading
- Balance protein, carbs and fats
- Heart disease prevention: 10 preventive measures
- Kiwi fruit nutrition and side effects
- How to read nutrition labels
Sources
- USDA FoodData Central, SR Legacy, European chestnuts roasted, FDC 170190, and raw peeled, FDC 170575. Values read from mirrors: roasted and raw peeled
- Tufts University: How to eat a chestnut
- FDA: Daily Value on the Nutrition and Supplement Facts Labels
This article is for general information and is not medical or dietetic advice. Talk to your doctor or a registered dietitian about your own needs, especially if you manage diabetes, kidney disease or a nut allergy.
Last reviewed and rewritten October 2026.