Flaxseed Calories & Nutrition Calculator

Flaxseeds contain 22.8g alpha-linolenic acid (ALA, 18:3 n-3) per 100g — the highest ALA concentration among all commonly consumed whole foods. Chia seeds follow at 17.8g, walnuts at 9.1g, hemp seeds at 8.7g, and canola oil at 9.1g. No other food regularly eaten in tablespoon quantities matches flaxseed's omega-3 density ^[1][2].

Per 1 tablespoon of ground flaxseed (7g): 1.60g ALA. Per 2 tablespoons (14g): 3.19g ALA — exceeding the adequate intake of 1.1–1.6g/day set by the Institute of Medicine. Even 1 teaspoon of ground flaxseed (3.5g) delivers 0.80g ALA, which is roughly half the daily adequate intake ^[1][3].

The ALA in flaxseed is predominantly in the oil fraction, which constitutes 42% of the seed by weight. Of this oil, 53–58% is ALA — making flaxseed oil one of the most ALA-concentrated oils. However, whole unground flaxseeds often pass through the digestive tract intact, meaning the ALA is poorly accessible unless the seed coat is broken by grinding, chewing thoroughly, or soaking ^[2][4].

Flaxseeds provide 27.3g dietary fiber per 100g — among the highest of any commonly consumed seed. Chia seeds lead at 34.4g, but at typical serving sizes (1 tbsp), flaxseed's lower density means 7g of ground flaxseed delivers 1.9g fiber (7% DV) in just 37 calories. The fiber is approximately one-third soluble (mucilage) and two-thirds insoluble ^[1][2].

The soluble fiber in flaxseed is primarily mucilage — a gel-forming polysaccharide concentrated in the seed coat. When flaxseed is soaked in water, this mucilage swells to form a viscous gel. This same mucilage makes ground flaxseed useful as an egg substitute in baking (1 tbsp ground flaxseed + 3 tbsp water = 1 egg equivalent for binding) ^[3].

For food journaling, the absolute fiber contribution per tablespoon is notable: 1 tbsp ground flaxseed adds 1.9g fiber in just 37 kcal, while 2 tablespoons add 3.8g fiber in only 75 calories. At typical 1–2 tablespoon serving sizes, flaxseed is one of the most convenient high-fiber additions to meals — comparable fiber per serving to a half-cup of cooked oatmeal (2.0g) but in a much smaller volume ^[1].

Flaxseeds contain 1.64mg thiamine per 100g — 137% of the daily value and the highest concentration among all commonly consumed seeds and nuts. Sunflower seed kernels follow at 1.48mg (123% DV), hemp seeds at 1.27mg (106% DV), and pine nuts at 1.24mg (103% DV). Most other nuts and seeds have less than 0.7mg ^[1][2].

Per 1 tablespoon of ground flaxseed (7g): 0.115mg thiamine (10% DV). Per 2 tablespoons (14g): 0.23mg (19% DV). While this doesn't replace major thiamine sources like pork (0.89mg per 100g cooked) or fortified cereals, it's a meaningful supplementary contribution for a small-portion addition ^[1].

Toasting reduces thiamine modestly — approximately a 10% loss (1.64 → ~1.48mg/100g) based on thiamine's known heat sensitivity. Ground flaxseed stored at room temperature also loses thiamine over weeks due to oxidation. For maximum thiamine logging, freshly ground raw flaxseed delivers more than pre-ground or toasted varieties.

Flaxseeds provide 392mg magnesium per 100g — 93% of the daily value and among the highest concentrations of any commonly consumed seed. Pumpkin seed kernels (550mg) and hemp seeds (700mg) exceed flaxseed, but flaxseed outranks almonds (270mg), cashews (292mg), chia seeds (335mg), and sunflower seeds (325mg) ^[1][2].

Per 1 tablespoon of ground flaxseed (7g): 27.4mg magnesium (7% DV). Per 2 tablespoons (14g): 54.9mg (13% DV). Combined with flaxseed's potassium (813mg/100g) and phosphorus (642mg/100g), even small daily additions contribute meaningfully to mineral intake ^[1].

The magnesium in flaxseed is associated with phytic acid (phytate), which may reduce absorption. Soaking, sprouting, or fermenting flaxseed can reduce phytate content and may improve mineral bioavailability. For food journaling, the listed values represent total magnesium — the absorbed amount will be somewhat lower depending on preparation and the overall composition of the meal ^[3][4].

Whole and ground flaxseed have identical per-gram nutritional composition — 534 kcal, 42.2g fat, 18.3g protein, and 27.3g fiber per 100g. The difference is entirely about accessibility. The hard, glossy seed coat of whole flaxseed resists digestion: studies consistently show that whole flaxseeds often pass through the gastrointestinal tract intact and visibly undigested ^[2][3].

Grinding breaks the seed coat and exposes the oil-rich interior to digestive enzymes. This means the ALA, lignans, and other lipid-soluble compounds become bioavailable. For food journaling purposes, logging whole unground flaxseed at full nutritional value may overestimate what the body actually extracts — a rare case where the label overstates practical nutrition ^[2][4].

Practical implications: if you eat whole flaxseeds without chewing them thoroughly, consider logging at 50–70% of the listed values for a more realistic estimate. Ground flaxseed can be logged at full value. Pre-ground flaxseed (flax meal) should be stored in the refrigerator and used within 6–8 weeks, as the exposed oils oxidize rapidly at room temperature.