Peanuts pack the most protein of any common nut at about 26 grams per 100 grams, while cashews carry the least fat among popular everyday nuts at roughly 43 to 44 grams per 100 grams. No single nut wins both categories outright, so your best pick depends on which factor matters more to you.
Protein and Fat Content Compared
Here’s how the most popular nuts stack up per 100 grams (about 3.5 ounces) of raw kernels, ranked from highest to lowest protein:
- Peanuts: ~26 g protein, ~49 g fat
- Pistachios: 19–22 g protein, 44–45 g fat
- Almonds: 17–25 g protein, 43–51 g fat
- Cashews: 18–19 g protein, 43–44 g fat
- Walnuts: 14–16 g protein, 65 g fat
- Hazelnuts: 14–15 g protein, 60–62 g fat
- Pecans: 9 g protein, ~72 g fat
A clear pattern emerges: the nuts with the most protein tend to have moderate fat, while the fattiest nuts (pecans, walnuts, hazelnuts) also deliver the least protein. If you want to maximize protein while keeping fat in check, peanuts, pistachios, and cashews are your strongest options.
Best Protein-to-Fat Ratio: Peanuts
Peanuts are technically legumes, but most people treat them as nuts, and nutritionally they behave like one. At roughly 26 grams of protein per 100 grams, they outpace every tree nut by a wide margin. A single one-ounce handful (about 28 grams) delivers around 7 grams of protein and 14 grams of fat. That protein-to-fat ratio is hard to beat in the nut aisle.
The fat in peanuts is predominantly unsaturated, split between monounsaturated and polyunsaturated types. If you’re choosing between salted, honey-roasted, or plain dry-roasted, the plain versions keep added calories and sodium to a minimum without meaningfully changing the protein or fat numbers.
Best Tree Nuts: Pistachios and Cashews
If you’re strictly looking at tree nuts, pistachios and cashews share the top spot for the best protein-to-fat balance. Pistachios edge ahead on protein (19 to 22 grams per 100 grams), while cashews have a slight advantage on fat, coming in at the lowest of any common tree nut at around 43 grams per 100 grams.
A one-ounce serving of pistachios gives you about 6 grams of protein. Buying them in the shell naturally slows down eating, which can help with portion control. Cashews deliver a similar 6 grams of protein per ounce but also carry more carbohydrates than most nuts, around 20.5 grams per 100 grams. That higher carb content means cashews are slightly lower in total fat by weight, since carbs are taking up a bigger share of the nut.
Almonds deserve a mention too. A one-ounce serving (about 23 almonds) provides 6 grams of protein and 14 grams of fat, with 80% of that fat being monounsaturated. They land in the middle of the pack on both protein and fat, making them a solid all-around choice.
Nuts to Limit if Fat Is Your Concern
Pecans, walnuts, and hazelnuts sit at the opposite end of the spectrum. Walnuts contain about 65 grams of fat per 100 grams with only 14 to 16 grams of protein. Hazelnuts are similar at 60 to 62 grams of fat and 14 to 15 grams of protein. Pecans are the most lopsided of all: just 9 grams of protein alongside the highest fat content of any common nut.
That doesn’t make them unhealthy. Walnuts are one of the richest plant sources of omega-3 fatty acids, and all three contain valuable micronutrients. But if your goal is specifically more protein and less fat per serving, these three give you the least favorable tradeoff.
The Lowest-Fat “Nut” Most People Forget
Chestnuts are in a completely different nutritional category. A 100-gram serving of roasted chestnuts contains just 2.2 grams of fat and 3.2 grams of protein. They’re mostly starch and water, more similar to a potato than to an almond. Boiled chestnuts drop even lower, to about 1.4 grams of fat per 100 grams, and clock in at only 37 calories per ounce.
The tradeoff is obvious: chestnuts are extremely low in fat but also very low in protein. They’re a good option if you want a nut-like snack without the calorie density, but they won’t help you hit a protein goal.
Raw, Dry-Roasted, or Oil-Roasted
How your nuts are prepared matters less than you might think. Raw and dry-roasted nuts have nearly identical fat, protein, and carbohydrate profiles. One ounce of raw almonds has 161 calories and 14 grams of fat, while the same amount of dry-roasted almonds has 167 calories and 15 grams of fat. The small difference exists because roasting removes moisture, so the same weight of roasted nut is slightly more concentrated.
Oil-roasted nuts are only marginally higher in fat than dry-roasted ones. The bigger concern with flavored or coated varieties is added sugar, salt, and other ingredients that change the overall nutritional picture. Plain raw or dry-roasted nuts keep things simplest.
Practical Picks by Goal
Your best nut depends on what you’re optimizing for:
- Maximum protein per serving: Peanuts, then pistachios
- Lowest fat among common nuts: Cashews, then pistachios and almonds
- Best overall protein-to-fat ratio: Peanuts, followed by pistachios and cashews
- Lowest fat overall (including uncommon options): Chestnuts, by a wide margin
Mixing two or three of the top performers is a practical strategy. A handful that’s half peanuts and half pistachios, for example, gives you strong protein numbers with moderate fat and more variety in flavor and micronutrients than either nut alone.