TABLE 1.

Definition of nuts and seeds based on botanical and nutritional classifications (16–19)

	Nuts	Seeds	Legumes	Drupes
Botanical definition	1-celled, 1-seeded dry fruit with a hard shell (pericarp – the outer layer of the ovary wall) that does not fuse with the ovary wall and does not open at maturity	Embryonic plants enclosed in a nutrient-dense seed coat that works as stored food to nourish the plant as it grows. Some need husks removing before consuming	Have pods (shells) that contain multiple fruit inside. They twist apart to scatter the seeds inside	Drupes include a seed that is contained within a shell and is surrounded by a fleshy fruit. The seed may be discarded (e.g. peach), or eaten
	Chestnuts and hazelnuts	Brazil nuts, pine nuts, macadamias chia seeds, pumpkin seeds, flaxseeds/linseeds, poppy seeds, sesame seeds, sunflower seeds	Peanuts	Almonds, cashews, coconuts, pistachios, walnuts, pecans
Nutritional research definition	Almonds, Brazil nuts, cashews, hazelnuts, macadamias, peanuts, pecans, pine nuts, pistachios, walnuts.Note: peanuts are included because they have a similar nutrient profile to other tree nuts	Chia seeds, pumpkin seeds, flaxseeds/linseeds, poppy seeds, sesame seeds, sunflower seeds	—	—
Excluded from nutritional research definition	Coconut due to high saturated fat content.Chestnuts due to high carbohydrate and water content	—	—	—
Culinary definition	No precise cut-offs. All nuts and seeds that are edible and/or for cooking purposes. May also be classified for sensory components such as flavor or texture	—	—	—