Head-to-head comparison

Soy Protein Isolate vs Tempeh: Which Has More Protein?

Soy Protein Isolate vs Tempeh is a genuinely useful comparison because the two differ meaningfully on more than one axis, not just total protein.

Soy Protein Isolate

90.0gprotein / 100g

375 cal · 1.0g fat · $$ · Quality 0.9

Tempeh

19.0gprotein / 100g

192 cal · 11.0g fat · $$ · Quality 0.85

Soy Protein Isolate is in a different weight class here, protein-wise: 90.0g per 100g vs Tempeh's 19.0g, a 71.0g difference that's more about food category than food quality.

Soy Protein Isolate also carries the stronger amino acid profile (one of the highest-quality plant proteins, near-complete on its own), while Tempeh is DIAAS-adjusted, complete plant protein.

Cost is roughly comparable between the two ($$), so budget isn't the deciding factor here.

Soy Protein Isolate's typical serving also delivers more leucine (2450mg vs Tempeh's 1450mg) — relevant if the goal is maximizing the muscle-protein-synthesis trigger per meal, not just total grams.

Verdict

If raw protein density is what you're optimizing for, Soy Protein Isolate wins clearly. Choose Tempeh instead if its lower fat, cost, or prep time matters more to you than the extra grams.

Full nutrition comparison

Per 100gSoy Protein IsolateTempeh
Protein90.0g19.0g
Calories375192
Fat1.0g11.0g
Carbs2.0g9.4g
Fiber1.5g9.0g
Quality score0.90.85
Relative cost$$$$
Prep time1 min15 min

Frequently asked

Which has more protein, soy protein isolate or tempeh?

Soy Protein Isolate has 90.0g of protein per 100g compared to Tempeh's 19.0g.

Which is lower in calories?

Tempeh is lower in calories per 100g, at 192 vs the other's 375.