Best protein sources ranked
The best protein sources are complete proteins with high bioavailability and a decent grams-per-calorie ratio. Chicken breast, lean beef, fish, eggs, Greek yoghurt, and whey cover almost everything. Tofu, tempeh, and pea isolate handle the plant side.
- Bioavailability matters more when your total protein intake is low.
- Animal sources are complete proteins — easy to hit targets with.
- Plant builders: soy, tempeh, lentils, pea isolate. Combine for completeness.
- Protein density (g per 100 g of food) matters when calories are tight.
- Whey is the fastest, cheapest gram-for-gram protein source available.
How to read this table
- Protein per 100 g — the raw count. Higher is better when calories are tight or stomach space is limited.
- Bioavailability — how much of the protein your body can actually use. Animal sources score highest; plant sources benefit from variety.
- Density — protein vs everything else in the food. A high-density food gives you more protein per calorie.
Ranked sources
| Food | Protein / 100 g | Bio | Note |
|---|---|---|---|
| Chicken breast (cooked) | 31 g | high | Lean, cheap, easy. The default for most lifters. |
| Whey protein isolate | 88 g | high | Fastest gram-per-£. Hits 25g per scoop, no cooking. |
| Lean beef mince (5%) | 26 g | high | More fat than chicken — choose 5% to keep cals reasonable. |
| White fish (cod, haddock) | 24 g | high | Very lean. Easy to digest, mild flavour. |
| Salmon | 22 g | high | Protein plus omega-3s. Twice a week is plenty. |
| Eggs (whole) | 13 g | high | Highest bioavailability score of any food. |
| Egg whites | 11 g | high | Pure protein, no fat. Useful when calories are tight. |
| Greek yoghurt (0%) | 10 g | high | Convenient, satisfying, doubles as a snack. |
| Cottage cheese | 11 g | high | Slow-digesting casein. Useful before bed. |
| Tuna (in spring water) | 23 g | high | Cheap, lean, no cooking. Cap at 2–3 tins/week (mercury). |
| Tofu (firm) | 12 g | medium | Best plant option — complete protein, takes flavour well. |
| Tempeh | 19 g | medium | Fermented soy. Denser and chewier than tofu. |
| Lentils (cooked) | 9 g | medium | Cheap and filling, but you need a lot to hit targets. |
| Pea protein isolate | 80 g | medium | Best plant-based powder. Combine with rice protein for full profile. |
How to actually combine these
A useful day might look like: Greek yoghurt and whey at breakfast, chicken and rice at lunch, salmon with vegetables for dinner, cottage cheese before bed. That stacks to ~180 g protein without much effort.
Plant-based building
Tofu and tempeh are complete proteins. Lentils, chickpeas, beans provide solid protein per serving but at lower density — you'll need bigger portions or combinations. Pea protein isolate fills the gaps fast. Combining soy with cereals (rice, oats) gives you a complete amino acid profile across a meal.
Common questions
- Do I have to eat meat to build muscle?
- No. Tofu, tempeh, lentils, beans, dairy if you eat it, and a pea protein powder will all work. You may need slightly more total grams to compensate for lower bioavailability in some plant sources.
- Is plant protein worse than animal protein?
- Gram for gram, most plant sources are slightly less bioavailable. But the difference shrinks once you're hitting your daily target with variety. For most people, the gap is too small to worry about.
- Are protein bars a good source?
- Sometimes. Read the label. Many are mostly sugar and fat with a bit of protein. A good bar has at least 15–20 g protein and isn't loaded with added sugar.
Related reading
Sources
- Dietary protein and muscle in aging people: the potential role of the gut microbiome — Ni Lochlainn M, et al.. Nutrients (2018).
- Effect of protein source and resistance training on body composition and sex hormones — Joy JM, Lowery RP, et al.. Journal of the International Society of Sports Nutrition (2014).