Mackerel

Food · Protein · Food, Typed Supps

A smaller, cheaper fish that often beats salmon on omega-3 per serving.

Stage by stage

Intake (Chewing begins): Chewing begins breaking down the fish protein and fat structure.
Stomach (Protein digestion starts): Stomach enzymes begin digesting its protein and releasing fat.
Small intestine (Fat & protein absorbed): Omega-3 fats (EPA/DHA) and amino acids are absorbed together in the small intestine.
Bloodstream & tissues (Incorporated into cell membranes): EPA and DHA are incorporated into cell membranes, particularly heart and brain tissue.

Timing

Any meal; its own fat content helps absorb its fat-soluble nutrients.

Time to effect

Weeks: Regular intake gradually shifts cell membrane fatty acid composition, similar to other oily fish.

Allergens

Contains: Fish. Derived from what this food is, not from a product label.

Eating patterns

Fits: Pescatarian, Kosher, Keto, Gluten-free. Depends on the product: Halal, Low-FODMAP.

Satiety

165 on the satiety index, where white bread is 100 — high. Modelled from the Holt et al. (1995) measurements.

Environmental footprint

13.6 kg CO2e and 3691 litres of freshwater per kg, matched to "Fish (farmed)" in Poore & Nemecek (2018), Science 360.

Cost band

Mid — roughly £11 per kg, as a band midpoint rather than a price.

Key nutrients

Omega-3 (EPA/DHA)
Complete protein
Vitamin D
Selenium

Nutrition per 100g

Calories: 134.1
Protein: 19.3g
Carbohydrate: 0g
of which sugars: 0g
Fat: 6.3g
of which saturated: 2g
Fibre: 0g
Sodium: 59mg

Food vs. supplement

A 3.5oz serving of mackerel can provide over 2g of combined EPA/DHA — more than most single fish oil capsules — along with protein and vitamin D a capsule does not supply.

Kitchen tip

Its stronger flavor holds up well to high heat — grilling or pan-searing skin-side down for a few minutes per side works better than gentler cooking methods.

Common myth

Mackerel is too high in mercury to eat regularly. In reality: Smaller, shorter-lived species like Atlantic mackerel are generally low-mercury choices — it is king mackerel, a larger and longer-lived species, that carries the higher-mercury advisory.