Soy protein isolate (unflavored)
Typical label values; a complete plant protein and usually the cheapest vegan powder.
1 Amount
How it fits your macros
Get your daily targets with the macro calculator to see what share of your day this portion covers.
Soy protein isolate for gym-goers
Per 100 g, soy protein isolate (unflavored) provides 365 kcal, 85 g protein, 3 g carbohydrate (0.5 g fiber, 0 g sugars) and 3 g fat (0.5 g saturated). At 23.3 g of protein per 100 kcal, it ranks among the most protein-dense foods, which helps a lot when calories are tight on a cut.
A typical serving (1 scoop, about 30 g) comes to roughly 110 kcal and 25.5 g protein.
These are typical averages. Brand, variety, ripeness and cooking method all shift the numbers, so weigh food in the same state (raw or cooked) as the entry you log.
About Soy protein isolate
Soy protein isolate, made from defatted soybeans, is the classic complete plant protein, with all the essential amino acids in proportions close to animal sources. At about 85% protein it's denser than pea isolate and usually the cheapest vegan powder. You also get a useful dose of iron, around 14 mg per 100 g in this unflavored entry.
In a gym diet
Roughly 25 g of protein for about 110 kcal per 30 g scoop makes it efficient on a cut and easy to add during a bulk. Its protein quality scores are high for a plant source. Leucine is a little lower than in whey, and a slightly bigger serving makes up for it.
Preparation and cooking
It mixes smoothly, with a mild beany note that cocoa, coffee, vanilla or fruit cover easily. Left to sit it thickens a bit, and it works well in baking, smoothies and savory batters. Log any plant milk separately, since soy and oat milks bring their own protein and carbohydrate.
Buying and storage
Some soy blends add fillers or sugar, so compare protein per scoop across labels and look at the sodium line. Informed Sport or NSF Certified for Sport certification is the safe bet. Keep the powder dry and sealed so it tastes fresh.
Things to watch
Soy is a major allergen, and sodium is fairly high at about 300 mg per scoop. Current research doesn't support worries about soy and male hormones at normal intakes, but if you have a thyroid condition or take certain medications, follow your clinician's advice.
Meal ideas
- Mocha shake: soy protein, cold coffee, soy milk, cocoa and ice.
- Vegan protein muffins: soy isolate, oat flour, mashed banana and blueberries baked together.
- Higher-protein tofu scramble: whisk a little soy isolate into silken tofu before cooking.
Nutrient highlights
Excellent source (20% DV or more per 100 g): Iron (78%) and Zinc (36%).
Good source (10–19% DV per 100 g): Calcium (14%), Potassium (11%), and Magnesium (10%).
How it ranks among 8 Protein Supplements
| Protein per 100 kcal | 23.3 g | #3 of 8 |
| Protein per 100 g | 85 g | #3 of 8 |
| Fiber per 100 g | 0.5 g | #3 of 8 |
| Lowest calories per 100 g | 365 kcal | #3 of 8 |
Ranked within this category of the gym.diet food database (1 = best for that measure).
Similar foods
Whey protein isolate (unflavored)
370 kcal · P 88 · C 3 · F 1
→Micellar casein protein (unflavored)
360 kcal · P 80 · C 6 · F 2
→Collagen peptides (unflavored)
360 kcal · P 90 · C 0 · F 0
→Egg white protein powder (dried egg white)
382 kcal · P 81.1 · C 7.8 · F 0.3
→Pea protein isolate (unflavored)
380 kcal · P 80 · C 4 · F 6
→Whey protein concentrate 80% (unflavored)
400 kcal · P 78 · C 8 · F 6
Compare Soy protein isolate with Whey protein isolate (unflavored) →
Source
Approximate per-100 g values compiled from USDA FoodData Central (SR Legacy / Foundation Foods), rounded. Daily Values are the U.S. FDA reference amounts for adults (2,000 kcal diet).
Frequently asked questions
How many calories are in soy protein isolate?
Soy protein isolate (unflavored) has about 365 kcal per 100 g, or roughly 110 kcal per 1 scoop (30 g).
How much protein is in soy protein isolate?
About 85 g of protein per 100 g and 25.5 g per 1 scoop. That works out to 23.3 g per 100 kcal, so it's a very protein-dense food.
Is soy protein isolate good for cutting or bulking?
With this much protein per calorie, it's especially useful when cutting, and it works in any phase.
Does soy protein affect testosterone in men?
Reviews of clinical studies found that soy protein at normal dietary intakes doesn't meaningfully change testosterone or estrogen in men. If you have specific hormonal health concerns, follow your clinician's advice.
Is soy protein better than pea protein?
Soy has a more complete amino-acid profile on its own and is usually cheaper. Pea suits people who avoid soy. Decide on allergies, taste and budget.
Nutrition Facts
* The % Daily Value tells you how much a nutrient in a serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice. Values approximate.