Tofu

Food · Protein · Food, Typed Supps

A plant protein whose calcium content depends entirely on how it was made.

Stage by stage

Intake (Soft, water-rich structure): Its soft structure breaks down easily with chewing.
Stomach (Slower plant protein digestion): Plant protein digestion begins, generally more slowly than animal protein.
Small intestine (Protein, isoflavones & calcium absorbed): Protein, isoflavones, and (if calcium-set) calcium are absorbed.
Bone & tissue (Calcium & isoflavone activity): Absorbed calcium supports bone maintenance; isoflavones circulate with mild oestrogen-like activity.

Timing

Check the ingredient label for "calcium sulfate" if calcium content matters to you.

Time to effect

Weeks: Regular intake contributes to protein and, if calcium-set, calcium status.

Allergens

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

Eating patterns

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

Satiety

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

Environmental footprint

3.2 kg CO2e and 149 litres of freshwater per kg, matched to "Tofu" in Poore & Nemecek (2018), Science 360.

Cost band

Mid — roughly £7 per kg, as a band midpoint rather than a price.

Key nutrients

Plant protein
Isoflavones
Calcium (if calcium-set)
Iron

Nutrition per 100g

Calories: 129.8
Protein: 12.8g
Carbohydrate: 0g
of which sugars: 0g
Fat: 8.3g
of which saturated: 1.2g
Fibre: 1g
Sodium: 22mg

Food vs. supplement

Tofu’s calcium content varies enormously by brand — only tofu made with a calcium sulfate coagulant provides meaningful calcium; nigari-set tofu provides very little, unlike a standardized calcium supplement’s consistent dose.

Kitchen tip

Pressing it for 15 to 20 minutes before cooking removes excess water so it browns instead of steaming in the pan.

Common myth

“Soy foods disrupt hormone levels in men.” In reality: Large human studies and reviews haven’t found meaningful effects on testosterone or oestrogen levels in men from typical soy food intake.