Peanut butter is a good source of protein
Short answerNot the way you think
On this page
Not the way most people think. Two tablespoons of peanut butter have 7 g of protein and 191 calories. That’s 3.7 g of protein per 100 calories, less than a plain bagel at 4.0. Peanut butter is good food, but it’s mostly fat, and it won’t carry a meal’s protein on its own.
What we’d do
Keep eating peanut butter if you like it, and count it as a fat that brings some protein along. Don’t build a meal’s protein around it. Pair it with a food that carries the protein, like peanut butter toast next to a Greek yogurt, or a spoonful in oatmeal made with milk and a scoop of whey. If you want a nut or seed for protein, pumpkin seeds do best at 5.4 g per 100 calories.
If you remember three things
- 2 tablespoons: 7 g of protein, 191 calories.
- Per calorie, a bagel has more protein. 4.0 g per 100 calories against 3.7.
- 25 g of protein from peanut butter alone is about 670 calories. From grilled chicken breast it’s about 125.
Why people believe it
Peanuts are legumes, like beans, and peanut butter shows up on every list of protein foods. Gram for gram, it really is high in protein. Per 100 g, peanut butter has 22.2 g of protein, about the same as raw chicken breast at 22.5 g.
The catch is everything else in it. That same 100 g of peanut butter has 598 calories. The raw chicken breast has 120. Most of peanut butter’s calories come from fat, which is why it tastes so good and why the protein comes with a big calorie bill.
Per calorie, it’s near the bottom
| Food | Serving | Protein | Calories | Protein per 100 calories |
|---|---|---|---|---|
| Grilled chicken breast | 3 oz | 26 g | 128 | 20.2 g |
| Nonfat Greek yogurt | 5.3 oz cup | 15 g | 88 | 17.3 g |
| Pumpkin seeds | 1 oz | 9 g | 158 | 5.4 g |
| Whole wheat bread | 1 slice | 4 g | 81 | 4.9 g |
| Plain bagel | 1 medium | 11 g | 277 | 4.0 g |
| Peanut butter | 2 tbsp | 7 g | 191 | 3.7 g |
| Almonds | 1 oz | 6 g | 164 | 3.7 g |
| Quinoa, cooked | 1 cup | 8 g | 222 | 3.7 g |
Calling peanut butter a protein food is a bit like calling pizza a vegetable because of the tomato sauce. The protein is there, it’s just not what most of it is.
To get 25 g of protein from peanut butter alone, you’d eat about 7 tablespoons, about 670 calories. You’d get the same protein from 3 oz of grilled chicken breast in about 125 calories.
The sandwich test
A peanut butter sandwich, two tablespoons on two slices of whole wheat bread, has about 15 g of protein. More than half of it comes from the bread. A turkey sandwich on the same bread, with 3 oz of turkey breast, has about 33 g.
| Lunch | Protein | Calories |
|---|---|---|
| Peanut butter sandwich | 15 g | 353 |
| Turkey sandwich | 33 g | 278 |
The turkey sandwich has more than twice the protein and fewer calories. For most adults the meal line is 25 to 35 g, and the peanut butter sandwich doesn’t reach it.
Where peanut butter earns its spot
None of this makes peanut butter bad food. It’s a good spread, and Gyroscope’s first Protein Guide suggested it in place of butter. It keeps well, costs little and goes on almost anything.
The trouble starts only when it’s the main protein in a meal. Foods that taste savory but are low in protein can leave you wanting more. In a 2023 account of a Sydney feeding trial, when people’s diets were cut from 15% to 10% protein, they ate 12% more calories, mostly from savory snacks. Peanut butter isn’t low in protein, but at 3.7 g per 100 calories it won’t fill the gap fast.
3 sources
- USDA FoodData Central, Peanut butter, smooth style, with salt, SR Legacy record 174266fdc.nal.usda.gov
- USDA FoodData Central, SR Legacy records 174899 (bagel), 172688 (whole wheat bread), 170567 (almonds), 170556 (pumpkin seeds), 168917 (quinoa), 171077 and 171534 (chicken breast), 174516 (turkey breast), 170894 (Greek yogurt)fdc.nal.usda.gov
- Raubenheimer and Simpson, Protein appetite as an integrator in the obesity system: the protein leverage hypothesis, Philosophical Transactions of the Royal Society B, 2023pmc.ncbi.nlm.nih.gov
