Tofu and soy foods: protein per portion and how to cook them

The first question most people ask after buying a block of tofu is arithmetic, not culinary: how much protein is actually in there, and is it worth bothering with next to chicken and eggs. The second question arrives after the first attempt at cooking it — why did it come out soggy and bland. Both have short answers.

What a portion actually gives you

The numbers below are rounded averages. They shift between brands, and they shift far more with cooking — tofu fried in two tablespoons of oil is not the same food, calorie-wise, as tofu from the oven.

• Firm tofu, 100 g: around 15 g protein, 140 kcal, 8 g fat, barely 1 g fibre.
• Silken tofu, 100 g: around 6 g protein and 60 kcal — less protein simply because there is more water.
• Tempeh, 100 g: around 19 g protein, 195 kcal and 5–7 g fibre.
• Edamame, 100 g of cooked beans: around 11 g protein, 120 kcal, 5 g fibre.
• Unsweetened soy milk, 250 ml: around 8 g protein and 90 kcal.
• Soy chunks or mince, 100 g dry: around 50 g protein and 330 kcal, though soaking roughly triples the weight.

A realistic portion of firm tofu is 150–200 g, so 22–30 g of protein for 210–280 kcal. That sits in the same bracket as a tin of tuna plus a bit more, and the comparison is worth making properly — the piece on how much protein tinned tuna delivers has those numbers side by side.

Among plant sources, soy is the closest thing to meat and dairy in amino acid profile. Leucine, the amino acid that does most of the work in triggering muscle building, makes up roughly 8 per cent of soy protein, so 25–30 g of soy protein in a meal does the job. With plant sources it generally pays to aim at the upper end of the portion, and how much of that the body actually puts to use is covered in the article on what one meal really delivers.

One detail that slips past most shoppers: some tofu is set with calcium sulphate, and that version carries 200–350 mg of calcium per 100 g. It is on the ingredients list. Tofu set with other coagulants has considerably less.

Fitting it into the day

The simplest approach is to treat tofu as a swap for one meat meal rather than as a side dish. If you need 130 g of protein a day, a 200 g portion of tofu covers about a quarter of it in one go.

Tempeh and edamame do a slightly different job. They bring 5 to 7 g of fibre per portion, which makes them a better fit for a lunch that has to hold until evening. Soy milk is the weakest source per volume, but it slots easily into porridge or a shake — and if the target is a genuinely high-protein breakfast, oats built around added protein beat milk alone, as in the 30 g protein porridge.

A practical habit: bake 400 g of tofu at once and keep it in the fridge for three days. Cold from the container it goes straight into a salad, a wrap or a rice bowl with no extra cooking.

Cooking it so it is not soggy

Firm tofu is still around 80 per cent water. So it gets pressed first: wrap the block in kitchen paper, put a plate and something heavy on top, and leave it 20–30 minutes. It loses 10–15 per cent of its weight, and only then can it brown properly.

After that the routine is the same every time: 2 cm cubes, a tablespoon of cornflour and salt, then 25–30 minutes in the oven at 200 °C with one turn, or 3–4 minutes a side in a hot pan. The cornflour is what builds the crust, not the oil.

Marinade only penetrates a couple of millimetres, so leaving it overnight buys you nothing. Season after cooking instead, or add the tofu to the sauce for the last five minutes. If you want a chewier, meatier texture, freeze the block whole and thaw it — the structure turns spongy and holds sauce far better.

Silken tofu is not for frying. It belongs in shakes, creamy sauces or a cocoa pudding. Tempeh turns bitter if you take it straight to the pan, so simmer or steam it for about ten minutes first.

Who it suits, and who it does not

It suits people who eat no meat or very little of it, anyone who does not tolerate lactose, and anyone who wants a cheap protein source that keeps well in the fridge. It also suits the goal of cutting saturated fat without cutting protein.

It does not suit anyone with a soy allergy, and there is no middle ground there. Tempeh and edamame can cause bloating in a sensitive gut because of the oligosaccharides they carry; tofu is the gentlest of the three, since most of that is lost in processing. If you take levothyroxine, soy can reduce how much of the medication you absorb, so the tablet and the soy meal need to be spaced apart — agree the timing with your doctor.

Simple combinations

• 200 g baked tofu, a cup of cooked rice and half a head of broccoli — roughly 40 g protein.
• 150 g tempeh in a wrap with cabbage slaw; tinned chickpeas fit well here if you want more fibre.
• Edamame as a snack, 150 g of beans with a little salt — around 16 g protein.
• Silken tofu, a banana and a spoon of cocoa in the blender for a creamy shake with no protein powder.
• Tofu alongside quinoa or buckwheat when you want a meat-free plate that holds until dinner.

Common myths

Soy lowers testosterone. The research generally shows that ordinary amounts, two to three portions a day, do not shift testosterone or oestrogen levels in men. Data on extreme intakes is thin, but almost nobody eats that much.

Tofu is an incomplete protein and must be combined. Soy contains all the essential amino acids in a decent ratio. It does not need rescuing by a grain in the same meal.

Tofu is automatically diet food. It is not. Half a block fried in plenty of oil clears 400 kcal easily, and battered restaurant tofu goes higher.

All soy products are the same. Nowhere near it. Tofu and tempeh are barely processed, while ready-made soy burgers and sausages often carry 1.5 to 2 g of salt per piece.

When to see a doctor

A rash, swelling of the lips or throat, or difficulty breathing after eating soy needs urgent care, not a wait-and-see approach. If you have thyroid disease or take thyroid hormone medication, sort out the meal and tablet timing with your doctor before soy becomes a daily habit. The same applies if you have been treated for a hormone-sensitive cancer — that conversation belongs with your oncologist, not a search engine.

The short version

Firm tofu gives about 15 g of protein per 100 g, tempeh about 19 g, edamame about 11 g. A realistic 150–200 g portion of tofu carries 22–30 g of protein, which puts it level with a meat meal. Press it, coat it in cornflour and salt, then bake at 200 °C — technique, not the ingredient, decides whether you end up liking it.