The 20 Best Plant-Based Protein Sources, Ranked by USDA Data

Top 20 Plant-Based Protein Sources per 100g

Soy Dominates — And It's Not Close

Dry roasted soybeans sit at 43.3g of protein per 100g, a number that rivals chicken breast and outranks most other whole foods in the USDA database. That figure is not a fluke of processing — it reflects soy's unusually high protein-to-mass ratio, which holds up across its many forms. The soy family as a whole is the most versatile plant protein category. Tempeh, made from fermented whole soybeans, delivers 20.3g per 100g alongside a firm, meaty texture that absorbs marinades well. It also provides prebiotic fiber from the fermentation process. Edamame — immature soybeans served in the pod — registers at 11.9g per 100g cooked, and a 155g cup of shelled edamame yields around 18g of protein. Tofu in its firm, calcium-set form comes in at 17.3g per 100g, higher than many people expect. The reason tofu varies so widely in published data is water content: different brands and styles press out different amounts of moisture. Extra-firm and pressed tofu skew toward the higher end of that range. For anyone building a plant-based diet around reliable protein sources, starting with soy in one of its forms — whether that is a 28g snack of dry roasted soybeans, a portion of tempeh at dinner, or edamame as a side — is the most straightforward path to competitive protein numbers without relying on processed supplements.

Seeds and Nuts: Protein-Dense but Calorie-Dense

Hemp seeds (31.6g), pumpkin seeds (30.2g), flaxseed (18.3g), chia seeds (16.5g), and almonds (21.5g) all rank high on protein per 100g. The trade-off is calorie density. Seeds and nuts range from roughly 480 to 580 calories per 100g, which reflects their high fat content. That fat is largely unsaturated and nutritionally valuable, but the calorie load is real. In practical terms, a 30g handful of hemp seeds delivers about 9g of protein at roughly 165 calories. A 30g serving of almonds provides 6.5g of protein at around 174 calories. These are useful additions to meals — stirred into oatmeal, blended into a smoothie, sprinkled over salads — but they are not efficient as primary protein sources for anyone managing overall calorie intake. Their value lies in stacking: adding 5–10g of protein to a meal that already has a legume or soy anchor. Pumpkin seeds are worth singling out. At 30.2g of protein per 100g and 8.82mg of iron (one of the highest iron values of any food in the USDA database), they double as a meaningful iron source — a nutrient that plant-based eaters need to track carefully. Hemp seeds also stand out for their omega-3 fatty acid content and the fact that they contain all essential amino acids in a favorable ratio, which makes them one of the more nutritionally complete plant protein options. Peanut butter, at 24g of protein per 100g, is accessible and calorie-dense (around 588 cal/100g), making it best used in measured portions — two tablespoons (32g) provide about 7.7g of protein and 190 calories.

Legumes: The Practical Everyday Sources

Lentils, chickpeas, black beans, and kidney beans all register between 8.7g and 9.0g of protein per 100g cooked. That sounds modest compared to soy or hemp seeds, but the calorie density tells a different story: cooked legumes run between 116 and 164 calories per 100g, far lower than seeds or nuts. A 200g serving of cooked lentils — roughly a generous cup — delivers around 18g of protein at 232 calories alongside 15–16g of dietary fiber. That combination of protein, fiber, and moderate calories is genuinely difficult to match from animal sources at a similar energy cost. Black beans and kidney beans follow a similar pattern. A 200g portion of black beans yields about 17.8g of protein with 17.4g of fiber at 264 calories. Chickpeas, at 8.9g protein and 7.6g fiber per 100g cooked, are the most commonly used legume globally and translate well across cuisines — roasted, hummus, curries, soups. One persistent misconception about plant protein deserves addressing here. The idea that plant proteins are "incomplete" and must be carefully combined within a single meal to achieve a full amino acid profile has been widely debunked. The original research on protein complementation was overstated. What matters is eating a variety of plant foods throughout the day, not engineering specific meal-level combinations. Legumes are lower in methionine and higher in lysine; grains are lower in lysine. Eating both over the course of a day — not necessarily at the same meal — provides the full amino acid spectrum. The same applies across the full range of plant foods on this list. Green peas (5.4g per 100g cooked) and quinoa (4.4g) are lower on the per-100g metric but still contribute meaningfully to daily totals. Quinoa in particular is notable as a grain-like seed that provides a complete amino acid profile. A 200g cooked portion adds 8.8g of protein. Spinach at 2.9g per 100g raw is not a primary protein source, but it is worth noting that its protein content is unusually high for a leafy vegetable relative to its calorie level — 100g of raw spinach has only 23 calories.

Practical Protein Targets for Plant-Based Diets

• Aim for 1.2–1.6g of protein per kilogram of bodyweight if you are physically active. This is slightly higher than the typical recommendation for mixed diets, partly to account for lower leucine concentrations in most plant proteins — leucine is the amino acid most directly linked to muscle protein synthesis signaling.
• Use soy products — tempeh, firm tofu, edamame, or dry roasted soybeans — as protein anchors for at least one or two meals per day. Their protein concentrations are the most competitive in the plant kingdom and do not require large portion volumes to contribute meaningfully.
• Layer in legumes at every opportunity. A cup of lentils or black beans added to a grain bowl, soup, or wrap adds 15–18g of protein alongside fiber that most plant-based diets are already strong on.
• Use seeds and nuts to top up individual meals rather than as primary sources. Two tablespoons of hemp seeds adds 5–6g of protein to oatmeal or a smoothie; a 30g handful of pumpkin seeds adds 9g alongside significant iron and zinc.
• Track your intake for a week to calibrate your portions. Most people significantly underestimate how much volume of plant foods is needed to consistently hit protein targets in the 100–140g per day range.
• Eating a varied diet across legumes, soy products, whole grains, nuts, and seeds throughout the day — rather than at specific combined meals — is sufficient to obtain all essential amino acids without any supplementation beyond possibly vitamin B12.