Which foods have the most protein per calorie?
Egg whites, white fish, prawns, chicken breast and fat-free Greek yoghurt lead: all deliver 17 to 25 g of protein per 100 calories. Cheese, nuts, nut butter and fatty meats fall to under 10 g per 100 calories, which makes them protein-containing foods rather than efficient protein sources.
Key takeaways
- In a calorie deficit the useful measure is grams of protein per 100 calories, not grams per 100 grams.
- Lean animal protein and fat-free dairy sit at the top: 17 to 25 g per 100 calories.
- Nuts, nut butter and cheese sit near the bottom, at 4 to 8 g per 100 calories.
- The ranking changes what to eat when the day is tight. It does not change what is healthy.
- Outside a deficit this measure matters far less, and fat and fibre are not problems to be minimised.
Outside a deficit, protein per 100 g is the right way to compare foods. Inside one, it is the wrong measure, because the limited resource is not weight on the plate. It is calories in the day.
The ranking
Grams of protein per 100 calories, from USDA FoodData Central. Cooked weights for meat and fish.1
| Food | Protein per 100 kcal |
|---|---|
| Egg white | 24 g |
| Cod | 21 g |
| Prawns | 20 g |
| Fat-free Greek yoghurt | 20 g |
| Chicken breast, skinless | 19 g |
| Tuna, canned in water | 18 g |
| Turkey breast, skinless | 18 g |
| Cottage cheese, low fat | 13 g |
| Lean steak | 13 g |
| Tofu, firm | 11 g |
| Whole egg | 8 g |
| Lentils | 8 g |
| Salmon | 12 g |
| Cheddar cheese | 7 g |
| Peanut butter | 4 g |
| Almonds | 3.5 g |
The spread from top to bottom is roughly sevenfold, which is far larger than the difference between any two of these foods on protein per 100 g.
What the ranking is measuring
Fat carries more than twice the calories of protein per gram, so the leanest sources rise to the top almost automatically. That is the whole mechanism: the top of this table is lean protein and the bottom is fat with protein in it.
| Amount | Calories | |
|---|---|---|
| Egg whites | 270 g, about 8 whites | 125 kcal |
| Chicken breast | 100 g cooked | 165 kcal |
| Fat-free Greek yoghurt | 300 g | 150 kcal |
| Cheddar cheese | 120 g | 480 kcal |
| Almonds | 145 g | 840 kcal |
Six hundred calories separate the cheapest and most expensive way of reaching the same protein number. In a day with 1,600 calories in it, that is not a rounding difference.
When to use this and when to ignore it
Use it when calories are genuinely limited and the protein target is genuinely demanding, which is the situation in a meaningful deficit or when someone is trying to hold a target on a small appetite. It answers the question "where do I find 30 g that I can afford".
Ignore it the rest of the time. This is a ranking on one axis, and a diet designed entirely from the top of it is monotonous, low in fat and unlikely to survive a month. Nuts and olive oil and full-fat dairy are not problems; they are simply not efficient answers to this particular question.
The mistake worth avoiding is treating an efficiency ranking as a health ranking. Salmon is further down this table than cod and is not a worse food.
Why it matters more than the thermic effect
Protein per calorie is a bigger practical lever than anything about digestion costs. Swapping 145 g of almonds for 100 g of chicken frees up 675 calories for the same protein, which dwarfs any energetic advantage protein has in being digested.
It is also the mechanism behind the finding that matters in a deficit. Higher protein groups in the trials kept more lean mass and lost more fat, and hitting a higher protein target inside a restricted day is only possible if the protein is not also bringing most of the calories.2
Practical version
Four swaps cover most of it.
- Fat-free or low-fat Greek yoghurt instead of full fat, when the yoghurt is there for protein.
- Egg whites added to whole eggs, rather than more whole eggs, when you want the number higher.
- White fish and prawns on days where the budget is tight. Both are near the top and neither takes long to cook.
- Move the nuts and cheese out of the protein column in your head and into the fat column, where they belong.
For the rest of the reference numbers, high protein foods and how much they actually contain has the per-portion figures, and eating more protein while dieting has the day-to-day tactics.
More questions about Weight loss
What is the highest protein lowest calorie food?
Egg whites, at roughly 24 g of protein per 100 calories, followed closely by white fish such as cod and by prawns. Fat-free Greek yoghurt and cottage cheese are the best of the convenient options, at around 17 to 20 g per 100 calories with no cooking required.
Are nuts bad if I am trying to lose weight?
Not bad, just inefficient as a protein source. Almonds deliver about 3.5 g of protein per 100 calories, which means reaching a 30 g target from them costs around 840 calories. They are satisfying and nutritious, and they are a fat source with protein attached rather than the reverse.
Does this mean I should avoid fat?
No. This ranking answers one narrow question: which foods deliver protein cheaply when calories are limited. Fat is necessary, it makes food palatable, and a diet built entirely from the top of this list is one most people abandon. Use it to choose your protein sources, not to design everything on the plate.
