Head-to-head comparison

Soy Protein Isolate vs Kidney Beans (cooked): Which Has More Protein?

Soy Protein Isolate vs Kidney Beans (cooked) 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

Kidney Beans (cooked)

8.7gprotein / 100g

127 cal · 0.5g fat · $ · Quality 0.6

Soy Protein Isolate is in a different weight class here, protein-wise: 90.0g per 100g vs Kidney Beans (cooked)'s 8.7g, a 81.3g 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 Kidney Beans (cooked) is incomplete on its own — low in methionine, pairs well with grains.

On price, Kidney Beans (cooked) wins clearly — $ against Soy Protein Isolate's $$.

Soy Protein Isolate's typical serving also delivers more leucine (2450mg vs Kidney Beans (cooked)'s 600mg) — 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 Kidney Beans (cooked) instead if its lower fat, cost, or prep time matters more to you than the extra grams.

Full nutrition comparison

Per 100gSoy Protein IsolateKidney Beans (cooked)
Protein90.0g8.7g
Calories375127
Fat1.0g0.5g
Carbs2.0g22.8g
Fiber1.5g6.4g
Quality score0.90.6
Relative cost$$$
Prep time1 min90 min

Frequently asked

Which has more protein, soy protein isolate or kidney beans (cooked)?

Soy Protein Isolate has 90.0g of protein per 100g compared to Kidney Beans (cooked)'s 8.7g.

Which is lower in calories?

Kidney Beans (cooked) is lower in calories per 100g, at 127 vs the other's 375.