Plant-based protein sources: what are the best options?
Plant-based protein sources include pulses, soya products, nuts, seeds, grains and plant-based protein shakes. Protein content varies enormously, from 4g per serving (porridge oats) to 36g per serving (soya protein powder). Most plant sources are incomplete: they're missing one or more essential amino acids. The good news is that clever combinations solve this easily.
Whether you eat entirely plant-based or simply give meat less of a starring role, getting enough protein without animal products means knowing your sources and your portion sizes. This page gives you a concrete, numbers-based foundation, not vague advice, but actual grams, kilocalories and practical pairings.
The main categories of plant-based protein
Pulses
Pulses are the most underrated protein source in a plant-based diet. Black beans provide around 15g of protein per 100g cooked. Lentils come in at 9g per 100g cooked. Chickpeas offer 9g per 100g. The catch is that pulses also carry a fair amount of carbohydrate, averaging 20-25g per 100g cooked, which matters if you're watching your carb intake.
Pulses are incomplete proteins, lacking methionine, an essential amino acid. Pair them with grains (which do contain methionine) and that gap is filled. Rice with lentils is the classic example of this kind of complementary combination.
Soya products
Soya is the exception in the plant world. It's one of the few plant sources with a complete amino acid profile, comparable to animal protein. Tempeh delivers 19g of protein per 100g. Firm tofu comes in at 17g per 100g. Edamame contains 11g per 100g. Soya milk, meanwhile, provides only 3-4g per 100ml, similar to cow's milk but in a lower concentration than you might expect.
The bioavailability of soya protein is high. Soya isolate scores a full 1.0 on the PDCAAS scale (Protein Digestibility Corrected Amino Acid Score), the maximum possible. That makes soya the most efficient plant-based protein for muscle maintenance and recovery.
Nuts and seeds
Nuts and seeds provide protein, but also plenty of fat and calories. Hemp seeds top the list at 31g of protein per 100g. Pumpkin seeds contain 30g per 100g. Almonds sit at 21g per 100g. But the calorie density is steep: 100g of almonds also delivers 580 kcal. That makes nuts a useful extra rather than the backbone of a protein-rich meal if you're keeping an eye on calories.
Seeds like chia and flaxseed are often promoted as protein sources, but their real contribution is modest: chia offers 17g per 100g, though a typical 15g serving only supplies about 2.5g of protein. Handy as a supplement, not as a foundation.
Grains and pseudo-grains
Most grains are low in lysine, another essential amino acid. Pseudo-grains are the exception. Quinoa contains all nine essential amino acids and provides 14g of protein per 100g dry weight (roughly 4g per 100g cooked). Amaranth follows closely with 14g per 100g dry. Oats provide 13g per 100g dry, or 2.5g per 40g serving of porridge. Useful as a supplement, but not a primary protein source.
Plant-based protein shakes
Plant-based protein shakes fill the gap that whole foods leave behind. They're concentrated, calorie-efficient and easy to dose accurately. A 35g scoop of powder typically delivers 20-27g of protein for just 130-160 kcal. The best plant-based shakes combine several protein sources, such as pea and rice protein, to achieve a complete amino acid profile. That's exactly what to look for when choosing one.
Take a look at the plant-based shake range from Bioteïne if you're after something that fits neatly into a structured protein diet.
Comparison table: plant-based protein sources
| Protein source | Serving | g protein | kcal | Complete amino acid profile |
|---|---|---|---|---|
| Tempeh | 100g | 19g | 193 kcal | Yes |
| Tofu (firm) | 100g | 17g | 144 kcal | Yes |
| Edamame (cooked) | 100g | 11g | 121 kcal | Yes |
| Black beans (cooked) | 100g | 15g | 132 kcal | No |
| Lentils (cooked) | 100g | 9g | 116 kcal | No |
| Chickpeas (cooked) | 100g | 9g | 164 kcal | No |
| Split peas (cooked) | 100g | 8g | 118 kcal | No |
| Quinoa (cooked) | 100g | 4g | 120 kcal | Yes |
| Amaranth (cooked) | 100g | 4g | 102 kcal | Yes |
| Hemp seeds | 30g | 9g | 166 kcal | Yes |
| Pumpkin seeds | 30g | 9g | 162 kcal | No |
| Almonds | 30g | 6g | 174 kcal | No |
| Peanut butter (plain) | 30g | 8g | 188 kcal | No |
| Oats (dry) | 40g | 5g | 152 kcal | No |
| Seitan | 100g | 25g | 370 kcal | No |
| Plant-based protein shake | 35g powder | 24g | 145 kcal | Yes (blend) |
Nutritional data sourced from the Voedingscentrum and USDA FoodData Central.
Complete versus incomplete protein: what does it mean in practice?
Protein is made up of amino acids. Of the 20 amino acids, 9 are essential, meaning the body can't produce them itself. A protein source is called "complete" when all 9 essential amino acids are present in sufficient proportion. Animal products are almost always complete. Most plant sources aren't.
That sounds trickier than it actually is. The solution is simply combining sources, and you don't need to do this within a single meal. The body draws on a pool of amino acids across the day, so as long as you get all the essential amino acids within 24 hours, the system works. Still, it helps to know which combinations complement one another:
- Pulses + grains: pulses lack methionine, grains lack lysine. Together they cover both. Example: lentil soup with wholemeal bread.
- Nuts/seeds + pulses: hemp seeds are complete and top up the amino acid profile of chickpeas. Example: hummus with hemp seeds.
- Rice + pea protein: the combination used in many plant-based protein shakes to achieve a complete profile.
Soya, quinoa, amaranth and hemp seeds are the plant-based exceptions: complete on their own, no pairing required. If you'd rather not overthink variety, these are your simplest choices.
Want to understand exactly how much protein you need each day and how to get there? The Bioteïne high-protein diet guide offers a structured overview.
Plant-based protein sources when losing weight
Protein is the most satiating macronutrient. Studies show that a protein intake of 1.2-1.6g per kg of body weight per day is effective for weight loss while preserving muscle mass. This applies to plant-based protein too, provided the total intake and amino acid profile stack up.
When losing weight, it's all about the balance between high protein and relatively low calories. Plant sources vary considerably here:
- Tofu: 17g protein per 100g for just 144 kcal. A solid protein-to-calorie ratio.
- Tempeh: 19g protein per 100g at 193 kcal. Slightly higher in calories but very nutrient-dense.
- Lentils: 9g protein per 100g, but also 20g of carbohydrate. Fine within a mixed diet, worth watching if you're limiting carbs.
- Plant-based protein shake: 24g protein for 145 kcal. The most calorie-efficient way to boost your protein intake.
Not sure which phase of a diet you're in, or exactly how much protein you need? The Bioteïne phase test can help you work that out.
Common pitfalls with plant-based protein sources
The calorie density of nuts
Nuts are often framed as a protein source, and that's true up to a point. But 100g of almonds provides 21g of protein alongside 580 kcal. Compare that with 100g of chicken breast, which delivers 31g of protein for just 165 kcal. If you're watching calories, nuts are a supplement, not a foundation. Use them as a topping or snack in 20-30g portions, rather than as the main protein source in a meal.
The carbohydrates in pulses
Pulses are nutritious, but they contain substantially more carbohydrate than meat, fish or eggs. 200g of cooked lentils provides 18g of protein, but also 40g of carbohydrate. On a standard high-protein diet that's no issue at all. On a low-carb diet, it's worth factoring in. Plan your pulses strategically and lean on sources with a better protein-to-carb ratio to fill the gaps.
Digestion speed and absorption
Plant-based protein generally has a lower digestion speed and bioavailability than animal protein. The PDCAAS of pea protein sits at 0.89, soya isolate at 1.0, and rice protein at just 0.47. This means that with some plant sources, you need to eat slightly more to match the same amino acid absorption as animal protein. A practical rule of thumb: increase your daily protein target by 10-15% if you eat entirely plant-based. So a 100g animal-protein target becomes 110-115g of plant protein.
Seitan and gluten intolerance
Seitan is made from wheat gluten and delivers an impressive 25g of protein per 100g. However, it's unsuitable for anyone with coeliac disease or gluten sensitivity, something that's regularly overlooked in online lists. Always check the composition of plant-based products if gluten is a concern for you.
Plant-based options from Bioteïne
A fully plant-based diet that still delivers enough protein takes some planning. Plant-based protein shakes make it much easier to hit your daily targets without having to build elaborate meals every time. Bioteïne's shakes combine pea and rice protein, giving a complete amino acid profile with a PDCAAS comparable to soya.
One serving delivers 24g of protein for around 145 kcal, making it a practical meal replacement within a structured diet, a top-up alongside a lighter meal, or a recovery boost after exercise.
Browse the full range via Bioteïne's shake collection. Want to put together a complete starter pack, including phase-by-phase guidance? Head to the Bioteïne starter pack.
For further background on plant-based protein sources and dietary recommendations, the British Dietetic Association (BDA) also highlights the importance of combining plant sources and ensuring adequate total intake.
Frequently asked questions
How much protein do I need if I eat plant-based?
On a fully plant-based diet, the recommended intake is slightly higher than on a mixed diet, due to the lower bioavailability of plant protein. A practical guideline is 1.3-1.8g of protein per kg of body weight per day, depending on activity level and goals. This compensates for the lower PDCAAS of certain sources.
Is plant-based protein as effective as animal protein for maintaining muscle?
Yes, provided total intake is sufficient and the amino acid profile is complete. Recent research shows that at matched protein intake, the difference in muscle protein synthesis is small. The key phrase is "matched intake": plant-based eaters sometimes need to eat 10-15% more protein to achieve the same effect.
What's the best plant-based protein source for weight loss?
Tofu and tempeh have the best protein-to-calorie ratio among whole foods: 17-19g of protein for 144-193 kcal per 100g. Plant-based protein shakes are even more efficient: 24g of protein for around 145 kcal. That combination supports satiety and muscle maintenance during a calorie deficit.
Can I get enough protein without eating meat?
Yes. With a varied diet of pulses, soya products, nuts, seeds and grains, topped up with a plant-based protein shake, an intake of 100-130g of protein a day is entirely achievable. Planning is essential, and tracking what you eat with a nutrition app can help in the early stages.
Are nuts a good protein source?
Nuts do contain protein, but the calorie density is high. 100g of almonds provides 21g of protein for 580 kcal. That makes nuts a supplement rather than a primary protein source. Stick to 20-30g portions and pair them with more calorie-efficient sources like tofu or a protein shake.
Which plant-based protein sources are complete?
Soya (tofu, tempeh, edamame), quinoa, amaranth and hemp seeds all contain sufficient amounts of the 9 essential amino acids. Plant-based protein shakes based on a pea-rice blend are complete too. All other plant sources are incomplete and need to be paired with complementary sources.
How much protein is in a serving of lentils?
100g of cooked lentils contains around 9g of protein and 116 kcal. A standard 200g serving of cooked lentils therefore provides 18g of protein. Lentils are a solid source, but also contain 40g of carbohydrate per 200g, which is worth noting on low-carb diets.
What's the difference between pea protein and rice protein?
Pea protein has a high PDCAAS (0.89) and is rich in lysine but low in methionine. Rice protein has a lower PDCAAS (0.47) but does contain methionine. Together, they form a complete amino acid profile, which is why most high-quality plant-based protein shakes combine these two sources.