Hazelnuts
Food · Fat & Oil · Food, Typed Supps
Hazelnuts pack heart-healthy fat and a big mineral boost, but they're calorie-dense, so a small handful goes a long way.
Stage by stage
- Chewing (Mouth): Chewing crushes the dense kernel, releasing oleic-acid-rich oils, vitamin E, and minerals bound within its cell structure.
- Stomach Mixing (Stomach): The stomach churns the fat- and fiber-rich matrix, slowing gastric emptying, which contributes to hazelnuts' filling effect.
- Intestinal Absorption (Small intestine): The small intestine absorbs monounsaturated fat, alpha-tocopherol, copper, and manganese, though some fat stays trapped in undigested cell-wall fragments and is excreted rather than absorbed.
- Liver Processing (Liver): The liver processes absorbed oleic acid and phytosterols, which help lower LDL cholesterol, while vitamin E circulates as a systemic antioxidant.
Timing
Hazelnuts are typically eaten as a snack or mixed into meals; pairing them with food isn't required for absorption, but eating them alongside a meal can help blunt the blood sugar response of that meal.
Time to effect
- Weeks: Feelings of fullness appear within an hour or two of eating, but the LDL-cholesterol-lowering effects documented in clinical trials typically take about 4 to 12 weeks of daily consumption (roughly 30-69 g/day) to become measurable.
Allergens
Contains: Tree nuts. Derived from what this food is, not from a product label.
Eating patterns
Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Gluten-free. Depends on the product: Keto, Low-FODMAP.
Satiety
61 on the satiety index, where white bread is 100 — low. Modelled from the Holt et al. (1995) measurements.
Environmental footprint
0.4 kg CO2e and 4134 litres of freshwater per kg, matched to "Nuts" in Poore & Nemecek (2018), Science 360.
Cost band
Pricey — roughly £16 per kg, as a band midpoint rather than a price.
Key nutrients
Nutrition per 100g
- Calories: 642.7
- Protein: 14.8g
- Carbohydrate: 5.1g
- of which sugars: 4.4g
- Fat: 61.4g
- of which saturated: 2.7g
- Fibre: 10.4g
- Sodium: 3mg
Food vs. supplement
Whole hazelnuts combine monounsaturated fat, fiber, plant sterols, and vitamin E in a food matrix that isolated vitamin E or oil-based supplements don't reproduce, and part of their fat calories are excreted undigested rather than absorbed.
Kitchen tip
Roast hazelnuts lightly to bring out flavor and loosen their papery skins, and store them in a cool, airtight container since their high unsaturated-fat content makes them prone to rancidity; note that hazelnuts are a common tree nut allergen.
Common myth
"Hazelnuts and other nuts are so calorie-dense and fatty that eating them regularly causes weight gain." In reality: Because a portion of hazelnuts' fat stays locked in undigested cell-wall fragments and is excreted rather than absorbed, and because their fat, fiber, and protein promote satiety, systematic reviews and meta-analyses of hazelnut-enriched diets have found no significant weight gain from regular consumption at typical study doses.
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