The Best Carbs to Eat for Protein: Quinoa, Bulgur, Couscous, Rice, Potatoes, Pasta, and Lentils Compared
Data source ChatGPT and edited from answers to multiple questions. It does accord with the general wisdom being written. This is for a cook, not for a dietician, to help choose the most appropriate ingredients.
When most people think of protein, they imagine meat, fish, eggs, or beans. Yet, the carbohydrate foods we often treat simply as “fuel” can also contribute a surprising amount of protein to the diet. Grains, pseudo-grains, and starchy vegetables all differ widely in their nutritional makeup, and understanding these differences can help you make choices that are better aligned with your health goals.
This article will explore several popular carbohydrate and carb substitute foods —quinoa, bulgur, couscous, rice, potatoes, pasta, semolina, polenta, pearl barley and lentils—and compare them not only for their protein content but also for their gluten status, fibre, vitamins, and versatility. By the end, you’ll know which ones deliver the most nutritional value, how they stack up gram for gram, and which are suitable for gluten-free diets.
Why Protein in Carbohydrate Foods Matters
Protein is essential for building and repairing tissues, producing enzymes and hormones, and supporting immune function. For people who eat a mixed diet, most protein tends to come from animal products, but for vegetarians, vegans, or those looking to diversify their diet, getting protein from plant-based carb sources can make a noticeable difference.
Carbohydrate foods are usually consumed in larger portions than nuts or seeds, which means even a moderate protein percentage can add up. For example:
A standard serving of cooked quinoa (185 g, about 1 cup) provides 8 g of protein—not far behind a single egg (around 6 g).
A large baked potato (300 g) provides 7–8 g of protein, often overlooked.
A cup of lentils (200 g cooked) provides 18 g of protein, rivaling chicken breast for contribution to your daily intake.
Quinoa
The Protein-Rich Pseudo-Grain
Quinoa is technically not a cereal grain but a pseudo-grain, related to spinach and amaranth. Native to South America, it has become a global health food for good reason.
Protein: About 8 g per cup cooked (4.4 g per 100 g cooked).
Unique feature: Quinoa is one of the few plant-based sources that is a complete protein, containing all nine essential amino acids in adequate proportions.
Gluten-free: Yes. Naturally gluten-free and suitable for coeliacs (though always check for cross-contamination in processing).
Other nutrients: High in magnesium, iron, manganese, folate, and fibre.
Versatility: Works as a base for salads, pilafs, porridge, or as a rice substitute.
Verdict: Quinoa is arguably the most protein-dense carb option and particularly useful for vegetarians and vegans. Its complete amino acid profile makes it stand out.
Bulgur Wheat
A Nutty, High-Protein Grain
Bulgur is a whole grain made by parboiling, drying, and cracking wheat. Common in Middle Eastern cuisine (think tabbouleh), it’s quick to prepare and very nutrient-dense.
Protein: Around 5.6 g per cup cooked (3.1 g per 100 g cooked).
Gluten-free: No. Bulgur is a wheat product and unsuitable for people with coeliac disease or gluten intolerance.
Other nutrients: Excellent source of fibre, manganese, magnesium, and iron.
GI profile: Lower glycaemic index than white rice or potatoes, making it better for blood sugar control.
Verdict: Bulgur is one of the most protein-rich true grains, but it’s not an option for those avoiding gluten. For everyone else, it’s a very filling, nutritious choice.
Couscous
Convenient, But Not a Protein Powerhouse
Couscous is often mistaken for a grain but is actually a type of tiny pasta made from semolina (crushed durum wheat). Its reputation as a “health food” is a little misleading compared to whole grains.
Protein: 5.8 g per cup cooked (3.8 g per 100 g cooked).
Gluten-free: No. Couscous is wheat-based and contains gluten.
Other nutrients: Lower in fibre and micronutrients compared to bulgur or quinoa, unless enriched.
Convenience: Incredibly quick to prepare—just soak in hot water.
Verdict: Couscous is fine as a versatile base, but nutritionally it falls short compared to quinoa or bulgur. Those needing gluten-free options should avoid it.
Rice
The Global Staple
Rice is one of the most widely eaten foods in the world, with many varieties ranging from white and polished to brown, black, and red rice. Its protein content is modest but varies slightly depending on the type.
Protein: Around 4.2 g per cup cooked white rice (2.7 g per 100 g cooked). Brown rice is slightly higher, at about 5 g per cup cooked.
Gluten-free: Yes. Rice is naturally gluten-free and safe for coeliacs.
Other nutrients: Brown rice offers fibre, manganese, selenium, and magnesium. White rice is less nutrient-dense but often fortified.
GI profile: White rice has a high glycaemic index, while brown rice is moderate.
Verdict: Rice is not a protein powerhouse but is extremely versatile, affordable, and gluten-free. Brown or coloured rice varieties are far better choices than white for overall nutrition.
Potatoes
The Underestimated Protein Source
Potatoes are often pigeonholed as “empty carbs,” but this is unfair. When eaten with the skin, they are nutrient-rich and surprisingly protein-providing.
Protein: Around 7–8 g per large baked potato (2 g per 100 g cooked).
Gluten-free: Yes. Naturally gluten-free and suitable for coeliacs.
Other nutrients: Rich in potassium, vitamin C, and fibre (when eaten with skin).
GI profile: Can be high, but cooling cooked potatoes and eating them later increases resistant starch, lowering blood sugar impact.
Verdict: While lower in protein by weight than quinoa or bulgur, potatoes are eaten in large portions, making them a meaningful protein contributor. They are also very filling and versatile.
Pasta
A Familiar Carb with Steady Protein
Pasta is one of the most common carbohydrate foods worldwide, traditionally made from durum wheat semolina. Though it’s not often praised for protein, pasta actually contributes a steady amount.
Protein: Around 7–8 g per cup cooked (about 3.5 g per 100 g cooked).
Gluten-free: Standard pasta contains gluten, though gluten-free versions (made from corn, rice, or legumes) are widely available.
Other nutrients: Enriched pasta often provides B vitamins and iron. Whole wheat pasta boosts fibre and micronutrient content.
GI profile: Standard pasta has a medium glycaemic index (lower than white bread or potatoes), especially when cooked “al dente.”
Verdict: Pasta provides more protein than rice and is similar to couscous, but whole wheat or legume-based pasta options can dramatically increase both protein and fibre, making them excellent choices for health-conscious eaters.
Lentils
The Protein-Packed Carb Substitute
Strictly speaking, lentils are legumes rather than grains or starchy vegetables. However, many people use them as a carbohydrate substitute for rice or pasta, especially in vegetarian and vegan diets.
Protein: About 9 g per 100 g cooked, or 18 g per cup (200 g cooked). This is by far the highest in our list.
Gluten-free: Yes. Naturally gluten-free.
Other nutrients: Excellent source of iron, folate, potassium, and polyphenols. High in fibre and very filling.
GI profile: Low to moderate glycaemic index, making them excellent for blood sugar management.
Verdict: Lentils are not a grain, but when considered as a carb replacement, they are unbeatable in protein terms. For those aiming to maximise plant-based protein, swapping rice or pasta for lentils is one of the smartest moves.
Pearl Barley
The Hearty Traditional Grain
Barley has been cultivated for thousands of years and is a staple in soups, stews, and breads across Europe and Asia. Pearl barley is the most common form, where the husk and bran layers have been polished off for quicker cooking. This makes it less fibrous than whole (hulled) barley but still nutrient-rich.
Protein: Around 3.1 g per 100 g cooked, or about 6 g per 200 g cup.
Gluten-free: No. Barley contains gluten and is unsuitable for coeliacs.
Other nutrients: High in fibre (especially beta-glucans, which help lower cholesterol), selenium, manganese, and phosphorus.
GI profile: Low to medium, depending on processing. Hulled barley has a lower glycaemic index than pearl barley.
Verdict: Pearl barley is an excellent hearty grain, rich in fibre and beneficial for heart health. While not as protein-dense as quinoa or lentils, it has a solid nutritional profile and can be very filling. The gluten content, however, excludes it for those with intolerance.
Polenta
A Corn-Based Staple
Polenta is made from boiled ground cornmeal, a traditional Italian staple. It’s naturally gluten-free and can be served soft and creamy, or cooled and sliced for grilling or frying.
Protein: Around 2.0 g per 100 g cooked (about 4 g per 200 g cup).
Gluten-free: ✅ Yes. Naturally gluten-free (though cross-contamination is possible if processed near wheat).
Other nutrients: Provides vitamin A precursors (carotenoids), some fibre, but is generally low in protein compared to other grains.
GI profile: Medium to high glycaemic index, depending on preparation.
Verdict: Polenta is filling and gluten-free, but not a strong protein source. Best combined with beans, cheese, or lentils to boost protein intake.
Semolina
The Protein-Rich Wheat Base
Semolina is coarsely ground durum wheat, used to make pasta, couscous, and many traditional porridges or puddings. On its own, it’s often prepared like polenta but has a different nutritional profile.
Protein: Around 3.6 g per 100 g cooked (about 6–7 g per 200 g cup).
Gluten-free: ❌ No. Semolina is wheat and contains gluten.
Other nutrients: Rich in iron and B vitamins if enriched.
GI profile: Medium, similar to pasta, especially when prepared al dente.
Verdict: Semolina is slightly higher in protein than couscous per weight, but similar nutritionally. Like pasta, it’s best for those not needing gluten-free diets.
Protein Content of Carbohydrate Foods
| Rank | Food (cooked) | Protein (g per 100 g) | Typical Portion (g, cooked) | Protein per Portion (g) | Gluten-Free? |
|---|---|---|---|---|---|
| 1 | Lentils | 9.0 | 200 g (boiled, drained) | ~18 g | ✅ Yes |
| 2 | Quinoa | 4.4 | 180 g (boiled) | ~8 g | ✅ Yes |
| 3 | Couscous | 3.8 | 180 g (prepared) | ~7 g | ❌ No |
| 4 | Semolina | 3.6 | 180 g (prepared as porridge) | ~6.5 g | ❌ No |
| 5 | Pasta (wheat) | 3.5 | 200 g (boiled) | ~7 g | ❌ No (GF versions exist) |
| 6 | Bulgur | 3.1 | 180 g (boiled) | ~5.5 g | ❌ No |
| 6 | Pearl Barley | 3.1 | 180 g (boiled) | ~5.5 g | ❌ No |
| 8 | Brown Rice | 2.6–2.7 | 180 g (boiled) | ~5 g | ✅ Yes |
| 8 | White Rice | 2.7 | 180 g (boiled) | ~5 g | ✅ Yes |
| 10 | Potatoes (baked) | 2.0 | 300 g (1 large baked potato) | ~6 g | ✅ Yes |
| 10 | Polenta | 2.0 | 200 g (soft, cooked) | ~4 g | ✅ Yes |
Note: Nutrient values can vary slightly depending on brand, variety, and cooking method. Values are approximate.
Other Factors Beyond Protein
Amino Acid Profile:
Quinoa: complete protein.
Rice & potatoes: limited in lysine.
Wheat-based foods (bulgur, couscous, pasta): higher in methionine, but lower in lysine.
Lentils: high in lysine, making them the perfect complement to rice or pasta.
Fibre:
Whole wheat pasta and lentils are fibre superstars.
Quinoa and bulgur are excellent.
White rice and couscous lag behind.
GI profile:
Lentils and bulgur: low GI.
Pasta (especially al dente): medium GI.
Potatoes and white rice: higher GI.
Anything Else to Consider?
When deciding which carbohydrate foods to prioritise for protein, a few additional factors come into play:
Cooking Methods and Nutrient Retention
Overcooking rice or pasta can increase glycaemic impact and reduce texture/satiety.
Cooking “al dente” pasta keeps its GI lower.
Cooling potatoes, rice, or pasta after cooking increases resistant starch, which supports gut health.
Portion Sizes Matter
Potatoes may look lower in protein by weight, but since we often eat large servings, their protein contribution can rival that of rice or couscous.
Lentils pack the most protein per 100 g and per serving, making them unique among carb substitutes.
Processing and Refinement
Whole grain versions (brown rice, whole wheat pasta, hulled barley instead of pearl) usually offer more fibre, vitamins, and minerals.
Refined forms (white rice, couscous, pearl barley) are quicker to cook but lower in overall nutrient density.
Pairing for Amino Acid Completeness
Lentils (high in lysine) pair perfectly with rice, pasta, or barley (higher in methionine), creating a balanced amino acid profile.
Quinoa is the only “complete” protein here on its own.
For Children
Why carbs matter: Kids need steady energy for growth, play, and brain function. Carbohydrates should generally make up the biggest share of their calories.
Best choices
Whole grains (brown rice, oats, wholemeal bread, wholewheat pasta) – more fibre, B-vitamins, and slower release of energy.
Potatoes, sweet potatoes – nutrient-dense, versatile, can be roasted, mashed, or baked in wedges.
Fruit – natural sugar, vitamins, fibre. Good snack or dessert alternative.
Legumes (lentils, beans, chickpeas) – combine carbohydrate with protein and fibre.
Avoid too much: Sugary cereals, refined white bread, soft drinks.
For Older People
Why carbs matter: Energy needs are lower, but protein, fibre, and micronutrient needs may actually be higher. Large carb portions can cause blood sugar spikes or contribute to weight gain if not balanced.
Best carb or non-carb options
Vegetables (especially non-starchy ones like leafy greens, broccoli, cauliflower) – low in calories, high in fibre and nutrients.
Moderate whole grains – oats, wholemeal bread, quinoa, buckwheat. Smaller portions, but still important for fibre and heart health.
Root veg in moderation – carrots, beetroot, parsnips, potatoes (ideally roasted, steamed, or boiled rather than fried).
Low-carb swaps – cauliflower rice, courgette noodles, salads with seeds/nuts for bulk.
Extra considerations:
Protein is often more important than carbs in later life (muscle maintenance). Pair carbs with protein.
Softer textures may help if chewing is an issue → mashed root veg, porridge, soft fruits.
Key Differences
Children: More energy, so carbs are a mainstay. Emphasise whole, unprocessed sources.
Older adults: Less energy needed; focus on quality and portion control. Fibre and micronutrients are more important than bulk starch. Often benefit from some lower-carb, higher-protein swaps.
Who Should Eat What?
For Vegetarians & Vegans: Quinoa and lentils are the winners. Pasta with lentils is an excellent amino acid-balanced meal.
For Gluten-Free Diets: Safe: Quinoa, rice, potatoes, lentils. Avoid: bulgur, couscous, standard pasta. Gluten-free pasta is fine.
For Weight Management: Lentils and whole wheat pasta are filling and protein-dense. Bulgur is excellent too.
For Athletes: Potatoes (for potassium), lentils (for protein recovery), quinoa (for balanced amino acids).
Conclusion: The Best Carbs for Protein
If you’re looking purely at protein quality and quantity, quinoa and lentils stand out. Quinoa is a gluten-free complete protein, while lentils (though technically a legume) provide nearly triple the protein of rice or potatoes.
Bulgur remains one of the best true grains for protein, though it’s not suitable for gluten-free diets.
Pasta is more protein-rich than rice, especially when eaten whole wheat or legume-based, and combining pasta with lentils creates a nutrient powerhouse.
Couscous and white rice sit at the lower end nutritionally, but they still contribute useful calories and some protein.
Potatoes, often underestimated, provide meaningful protein in larger servings and deliver key micronutrients.
In short:
Best overall gluten-free protein source: Quinoa.
Highest protein carb substitute: Lentils.
Best traditional grain: Bulgur.
Best everyday staple: Brown rice.
Best comfort carb with a boost: Whole wheat pasta.
Most underrated: Potatoes.
Health vs Protein Scorecard
| Food (cooked) | Protein Quality ⭐⭐⭐⭐⭐ | Fibre ⭐⭐⭐⭐⭐ | Glycaemic Impact ⭐⭐⭐⭐⭐ | Micronutrients ⭐⭐⭐⭐⭐ | Gluten-Free? |
|---|---|---|---|---|---|
| Lentils | ⭐⭐⭐⭐⭐ (highest protein, 9 g/100 g, but incomplete alone) | ⭐⭐⭐⭐⭐ (very high fibre) | ⭐⭐⭐⭐ (low GI, very steady) | ⭐⭐⭐⭐ (iron, folate, potassium) | ✅ Yes |
| Quinoa | ⭐⭐⭐⭐ (4.4 g/100 g, complete protein) | ⭐⭐⭐⭐ (good fibre) | ⭐⭐⭐⭐ (medium GI) | ⭐⭐⭐⭐ (iron, magnesium, folate) | ✅ Yes |
| Bulgur | ⭐⭐⭐ (3.1 g/100 g, not complete protein) | ⭐⭐⭐⭐ (high fibre) | ⭐⭐⭐⭐ (low GI) | ⭐⭐⭐ (iron, manganese) | ❌ No |
| Pearl Barley | ⭐⭐⭐ (3.1 g/100 g) | ⭐⭐⭐⭐ (high fibre, beta-glucans) | ⭐⭐⭐ (low–medium GI) | ⭐⭐⭐⭐ (B vitamins, selenium) | ❌ No |
| Pasta (wheat) | ⭐⭐⭐ (3.5 g/100 g) | ⭐⭐ (low in refined pasta, ⭐⭐⭐ in whole wheat) | ⭐⭐⭐ (medium GI, better al dente) | ⭐⭐ (enriched versions add B vitamins/iron) | ❌ No (GF versions exist) |
| Couscous | ⭐⭐⭐ (3.8 g/100 g) | ⭐⭐ (fairly low fibre) | ⭐⭐ (medium–high GI) | ⭐⭐ (limited unless enriched) | ❌ No |
| Semolina | ⭐⭐⭐ (3.6 g/100 g) | ⭐⭐ (refined, low fibre) | ⭐⭐ (medium GI) | ⭐⭐ (enriched adds iron/B vitamins) | ❌ No |
| Brown Rice | ⭐⭐ (2.7 g/100 g) | ⭐⭐⭐ (moderate fibre) | ⭐⭐⭐ (medium GI) | ⭐⭐⭐ (manganese, selenium) | ✅ Yes |
| White Rice | ⭐⭐ (2.7 g/100 g) | ⭐ (very low fibre) | ⭐ (high GI) | ⭐⭐ (often fortified) | ✅ Yes |
| Potatoes | ⭐⭐ (2 g/100 g, better per portion) | ⭐⭐ (skin-on is better) | ⭐ (high GI, unless cooled) | ⭐⭐⭐ (vitamin C, potassium) | ✅ Yes |
| Polenta | ⭐ (2 g/100 g, low protein) | ⭐ (low fibre) | ⭐⭐ (medium–high GI) | ⭐⭐ (some carotenoids) | ✅ Yes |
⭐⭐⭐⭐⭐ = excellent
⭐⭐⭐⭐ = good
⭐⭐⭐ = average
⭐⭐ = poor
⭐ = very poor
This shows
Protein density ≠ overall healthiness.
A big baked potato beats bulgur in protein grams per portion, but bulgur (or quinoa) wins for steady energy, fibre, and balance.
Highlights
Best overall carb/substitute for protein & health: Lentils — high in protein, high in fibre, low GI, good micronutrients, gluten-free.
Best true grain: Quinoa — complete protein, good balance of fibre and micronutrients, gluten-free.
Most heart-healthy: Pearl barley (beta-glucans).
Most convenient but weaker: Couscous & semolina — moderate protein, but lower fibre and nutrients.
Most overrated carb (for protein): White rice and polenta — low protein, low fibre, high GI.
Underrated: Potatoes — not as balanced as bulgur/quinoa, but contribute more protein per portion than you’d expect, and excellent potassium.