Is peanut butter healthy?

Is peanut butter good for you, or is it a dessert dressed up as a health food? You'll find both answers online, often on pages that sell jars. The clearest answer comes from three kinds of evidence: what's in a serving, controlled feeding trials, and long-term studies that followed hundreds of thousands of people for decades. They agree on more than you might expect, and they disagree in one place that most articles skip.

This page covers peanut butter nutrition per serving, whether peanut butter is a good source of protein and fiber, whether its fat is healthy, what the heart and diabetes studies found, how it fits weight loss, which jar to pick, what a spoonful a day does, the side effects, peanut butter for kids, and how long a jar lasts. Is peanut butter bad for you? For most people, only when the spoon gets big.

Peanut Butter Nutrition Facts per 2 Tablespoons

The standard serving on a peanut butter label is 2 tablespoons, about 32 grams. Here's what USDA FoodData Central lists for regular smooth peanut butter with salt:

Values from USDA FoodData Central entry 174266, scaled to 32 grams and rounded. The unsalted version (entry 172470) has about 5 mg of sodium. Daily values are the FDA's adult figures.

About three-quarters of the calories in peanut butter come from fat, and about 15 percent come from protein. The vitamins and minerals are the underrated part. One serving covers about a quarter of the day's niacin and manganese and a fifth of the vitamin E, a nutrient found mostly in nuts, seeds and plant oils. USDA's newer lab analysis of creamy peanut butter (Foundation Foods entry 2262072) found slightly more protein and fiber, 7.7 grams and 2.0 grams per serving, at about 188 calories.

What is the recommended serving size for peanut butter?

For most adults, 1 to 2 level tablespoons at a time is a sensible portion. Two tablespoons match the label serving. One tablespoon, about 15 grams, is the serving the large Harvard heart study below used when it counted peanut butter. Level the spoon with a knife the first few times you measure, so you learn what a real serving looks like on your toast.

Is Peanut Butter a Good Source of Protein?

It's a decent source, not a great one. Two tablespoons give about 7 grams of protein, which is only about 15 percent of their calories. That makes peanut butter a fat-rich food that brings some protein, not a protein food. Here's how it compares per 100 calories, using USDA entries:

Our calculation from the USDA values per 100 grams. Jerky has about twice the protein per calorie of peanut butter but far more sodium, as our look at whether beef jerky is healthy shows.

The International Society of Sports Nutrition's protein position stand (Jäger and colleagues, 2017) suggests 20 to 40 grams of protein per meal for people who train. Reaching 20 grams from peanut butter alone takes about 5.6 tablespoons, roughly 540 calories. So use it for flavor and fat, and let milk, Greek yogurt, eggs, fish or soy bring most of the protein. Our list of the best snacks for weight loss compares snacks by calories, protein and fiber if you want ideas with a better ratio.

The bottom row of that table explains powdered peanut butter. It's made from roasted peanuts pressed to remove most of the oil, and defatted peanut flour carries more than four times the protein per calorie of regular peanut butter. Most powders add sugar and salt back, so check the label, and expect much of the rich flavor to leave with the oil.

Does Peanut Butter Have Fiber?

A little. Two tablespoons have about 1.6 grams of fiber in USDA's standard entry and about 2 grams in its newer analysis. That's 6 to 7 percent of the 28-gram daily value, so peanut butter isn't high in fiber. Whole peanuts keep a bit more: 32 grams of dry-roasted peanuts carry about 2.7 grams. If you want the fiber to count, put your peanut butter on whole-grain bread or oats, or eat it with fruit or vegetables.

Is Peanut Butter a Healthy Fat?

Mostly, yes. About half of the fat in regular peanut butter is monounsaturated, the main fat in olive oil, and about a quarter is polyunsaturated. Saturated fat makes up about a fifth. In USDA's newer analysis of creamy peanut butter, the monounsaturated share was even higher, at about 62 percent of the fat.

The best test of what that fat does is a controlled feeding study. In a double-blind trial at Penn State, Kris-Etherton and colleagues (1999) fed 22 adults five diets in random order: a typical American diet, a low-fat diet, and three diets rich in monounsaturated fat built on olive oil, peanut oil, or peanuts and peanut butter. Compared with the typical American diet, the high-monounsaturated diets lowered total cholesterol by 10 percent and LDL cholesterol by 14 percent, about as much as the low-fat diet did. Unlike the low-fat diet, they didn't lower HDL cholesterol, and they cut triglycerides by 13 percent, while the low-fat diet raised them by 11 percent.

One detail matters for how you use that result. The peanut diet also cut saturated fat from 16 to 8 percent of calories. It tested peanuts and peanut butter in place of fattier foods, not peanut butter piled on top of an unchanged diet.

Does peanut butter have saturated fat?

Yes, about 3.3 grams per 2 tablespoons, or 17 percent of the daily value. That isn't zero, and it adds up if you eat several servings a day. In normal portions, though, the unsaturated fat outweighs it by nearly four to one, which is why the peanut diet above still lowered LDL.

What about hydrogenated oil and trans fat?

Many regular jars add a small amount of hydrogenated vegetable oil to keep the peanut oil from separating. The trans fat worry came from partially hydrogenated oils. In 2015 the FDA determined they're no longer generally recognized as safe, and manufacturers couldn't add them to foods after June 18, 2018. USDA's entry for regular smooth peanut butter lists only 0.02 grams of trans fat per serving. Some no-stir jars that call themselves natural use palm oil instead, which adds a little saturated fat.

Is the omega-6 fat in peanut butter inflammatory?

The evidence says no. Peanuts are rich in linoleic acid, an omega-6 fat that some diet books blame for inflammation. In a systematic review of 15 controlled trials in healthy adults, Johnson and Fritsche (2012) found almost no trial evidence that eating more linoleic acid raised blood markers of inflammation.

Peanuts vs Peanut Butter: What the Long-Term Studies Found

Most pages quote nut research as if it were all about peanut butter. The large cohort studies split them apart, and the results aren't the same.

The largest analysis followed 210,836 US nurses and health professionals for up to 32 years. Guasch-Ferré and colleagues (2017) found that people who ate peanuts two or more times a week had a 13 percent lower risk of cardiovascular disease than people who rarely ate them. Peanut butter, counted in 1-tablespoon servings, showed no significant link with cardiovascular disease once the three cohorts were pooled.

A Dutch study of 120,852 adults aged 55 to 69 found the same split for death from any cause. In van den Brandt and Schouten (2015), people who ate 10 grams or more of nuts a day had a 23 percent lower death rate over 10 years than people who ate none, and peanuts on their own were linked to lower mortality. Peanut butter wasn't.

The peanut benefit isn't limited to affluent study volunteers either. Luu and colleagues (2015) followed 71,764 mostly low-income Black and white adults in the southern US and 134,265 adults in Shanghai. In the US group about half of the nuts eaten were peanuts, and in Shanghai only peanuts were measured. People in the top fifth of intake had a 21 percent lower death rate in the US cohort and a 17 percent lower rate in Shanghai, driven mostly by fewer deaths from cardiovascular disease.

Why would peanut butter look different from peanuts? The Harvard team adjusted its peanut butter results for white bread, soda and the overall glycemic load of the diet, because those foods often come with peanut butter. They still wrote that the eating pattern around peanut butter could be distorting the result, or that peanut butter may simply not affect risk. Added salt, sugar and oil in many jars are another possibility. A third is absorption. In a feeding study of 63 adults in Ghana, Brazil and the US, Traoret and colleagues (2008) found more fat left the body unabsorbed when people ate whole peanuts than when they ate peanuts as butter, oil or flour.

None of these studies linked peanut butter to higher risk. The fair reading is that the heart and longevity benefits quoted for nuts belong most clearly to whole peanuts and tree nuts, while peanut butter is a neutral-to-good food whose value depends on the jar and the bread under it. The one large study that found a clear benefit for peanut butter itself looked at diabetes, covered below.

Is Peanut Butter Good for Weight Loss?

It can fit, as long as you measure it. The big nut trials on body weight are summarized in the peanut butter answer of our guide to the best fruits for weight loss, so this section sticks to studies that used peanuts.

The classic one is small. Alper and Mattes (2002) gave 15 normal-weight adults about 505 calories of peanuts a day for 8 weeks with no other instructions. Without being told to, they ate less of everything else and made up for about 66 percent of the peanut calories. They gained about 1 kilogram, against the 3.6 kilograms the extra calories predicted. When the peanuts replaced other fats in their diet, their weight held steady.

Peanut butter deserves a closer eye than whole peanuts, though. Its fat is absorbed more completely, as the Traoret study showed, so the label calories are closer to what you actually take in. And spoonfuls go down fast. Three habits keep it working for you rather than against you:

• Measure it. One level tablespoon is about 96 calories. A heaping one can be nearly double.
• Spread it, don't scoop it. A thin layer on toast, fruit or oats is easier to keep at one serving than eating from the jar.
• Let it replace something. In the peanut studies, weight stayed level when peanuts took the place of other fats. Peanut butter in place of butter or a sweet spread is a swap. Peanut butter on top of them is extra.

Is Peanut Butter Healthy for Diabetics?

For most people with diabetes or prediabetes, yes, in measured portions. Two tablespoons have only about 7 grams of carbohydrate and 3.4 grams of sugar, and the fat and protein slow how fast a meal raises blood sugar.

The strongest data point is from the Nurses' Health Study. Jiang and colleagues (2002) followed 83,818 women for 16 years. Women who ate peanut butter five or more times a week had a 21 percent lower risk of developing type 2 diabetes than women who rarely ate it, after adjusting for body weight, exercise, smoking and other risk factors. It's an observational result, so it can't prove peanut butter caused the difference.

A small trial points to one reason it might help. Reis and colleagues (2013) added 42.5 grams of peanut butter, a little under 3 tablespoons, to a carbohydrate-heavy breakfast for 15 women with obesity and a high risk of diabetes. Compared with the same breakfast without peanuts, the peanut butter breakfast blunted the blood sugar rise after lunch, raised gut hormones linked to fullness, and reduced the women's desire to eat.

Pick an unsweetened jar, pair it with whole grains or fruit rather than white bread and jelly, and count it in your meal plan. If you use insulin or another medication that lowers blood sugar, ask your care team how it fits.

Which Peanut Butter Is Healthiest?

The healthiest peanut butter is usually the one whose ingredient list reads "peanuts" or "peanuts, salt." The differences between jar types are smaller than the marketing suggests, though. Here's 2 tablespoons of each, by USDA weights:

USDA entries 174266, 173806 and 172458. The peanuts-only column uses unsalted dry-roasted peanuts, which is what a jar labeled only "peanuts" contains before grinding. A salted natural jar adds sodium.

Three things stand out:

• Natural peanut butter saves about 2 grams of sugar per serving, roughly half a teaspoon, plus the added oil. It's a small win, and the calories barely change.
• Reduced-fat peanut butter is rarely worth it. It saves about 4 calories per 2 tablespoons, because carbohydrate fillers replace some of the fat and the serving weighs more. You give up fat that helps keep you full and gain carbohydrate.
• Salt is the easiest thing to fix. Unsalted jars drop sodium from about 136 mg per serving to almost nothing, which matters if you watch your blood pressure.

Honey, chocolate and other flavored spreads are closer to dessert, so read the Added Sugars line on the label. Powdered peanut butter, covered in the protein section, is the one version that really changes the numbers.

What Will Happen if I Eat a Spoonful of Peanut Butter Every Day?

Probably not much, if the spoonful is level and replaces something else. One level tablespoon adds about 96 calories, 3.6 grams of protein and 8 grams of mostly unsaturated fat, along with a steady supply of niacin, vitamin E and magnesium. Eating peanut butter most days is roughly the habit of the Nurses' Health Study women who had the lower diabetes risk.

The catch is arithmetic. Eaten on top of everything else, a daily tablespoon adds about 670 calories a week, and a daily heaping spoonful close to double that. That's why the size of the spoon matters more than the habit.

If you run, timing matters more than the amount. Our guide to what to eat before a long run explains how close to the start a peanut butter breakfast still sits well.

What Are the Potential Side Effects of Eating Peanut Butter?

For most people the side effects are about amount, not the food itself. The exceptions are worth knowing:

• Peanut allergy. National surveys by Gupta and colleagues found peanut allergy in about 2.2 percent of US children and 1.8 percent of US adults. Reactions can be severe, so anyone with a known allergy should avoid peanut butter completely.
• Calorie creep. At about 96 calories per level tablespoon, three unmeasured spoonfuls add nearly 300 calories to a day without feeling like a meal.
• Sodium. Salted peanut butter has about 136 mg per serving. That's modest, but it adds to what's in the bread.
• Aflatoxin. Molds that grow on poorly dried or stored crops, peanuts among them, can make a toxin called aflatoxin. Worldwide, Liu and Wu (2010) estimated it plays a role in 4.6 to 28.2 percent of liver cancer cases, most of them in sub-Saharan Africa, Southeast Asia and China, where hepatitis B is common and aflatoxin in food is largely uncontrolled. In the US, the FDA's guidance lets it treat peanuts and peanut products above 20 parts per billion of total aflatoxins as adulterated. Throw out peanuts that look moldy, shriveled or discolored.
• Choking in young children. The CDC lists whole or chopped nuts and chunks or spoonfuls of nut butters among the choking hazards for infants and toddlers.

Why do doctors say not to eat peanuts?

Most doctors don't, unless there's a specific reason. The advice usually traces back to one of four situations: a peanut allergy, a toddler who could choke on whole nuts, a weight-loss plan where calories are tight, or old advice for diverticular disease. That last one has been overturned. In 47,228 men followed for 18 years, Strate and colleagues (2008) found that nuts didn't raise the risk of diverticulitis, and the men who ate the most nuts had about a 20 percent lower risk, a borderline result.

Is Peanut Butter Healthy for Kids?

Yes, for children who aren't allergic, and introducing peanut early may help prevent the allergy in the first place. In the LEAP trial, Du Toit and colleagues (2015) assigned 640 infants with severe eczema, egg allergy or both to eat or avoid peanut foods until age 5. Among the 530 who tested negative on a skin-prick test at the start, 13.7 percent of the avoidance group had a peanut allergy at age 5, against 1.9 percent of the group that ate peanut.

That trial changed US advice. The 2017 guidelines from an NIH-sponsored expert panel (Togias and colleagues, 2017) recommend introducing peanut foods at 4 to 6 months for infants with severe eczema or egg allergy after allergy testing, at around 6 months for infants with mild to moderate eczema, and along with other solid foods for everyone else, as an AAFP summary lays out. Talk to your pediatrician before the first taste, especially for a high-risk baby.

Texture is the other half of safety. Never give a baby or toddler a spoonful or lump of peanut butter. Thin it, stir it into a puree or oatmeal, or spread it thinly on soft toast.

Does Peanut Butter Expire?

Yes, though slowly. Peanut butter is only about 1 percent water, so it usually spoils by going rancid rather than by growing germs. Rancid peanut butter smells like paint or old oil, tastes bitter and often looks darker and drier.

The Academy of Nutrition and Dietetics says an opened jar of regular peanut butter stays fresh for 2 to 3 months in the pantry or 3 to 4 months in the refrigerator. It adds that natural peanut butter, with no added sugar or oil, should go in the refrigerator. Unopened jars carry a best-by date. Toss any jar that smells off or shows mold.

What This Means for You

Peanut butter earns its place in a healthy diet when you treat it as a flavorful fat that brings some protein. Measure 1 to 2 level tablespoons, pick a jar that's mostly peanuts, and put it next to foods that supply what it lacks: protein from milk, yogurt or eggs, and fiber from whole grains and fruit. If you have the choice, a handful of whole peanuts has the stronger long-term evidence behind it.

Your results won't come down to one jar, though. They come from meals that are decent most days and workouts you keep doing for months, and the workouts are usually what slips first. Our roundup of the best workout apps for weight loss compares apps designed to make that part easier. In FitCraft, a 3D AI coach demonstrates each bodyweight and dumbbell exercise and says your name while you train, and streaks and leaderboards give you a reason to come back tomorrow. As Sarah, 27, put it: "First app that made exercise feel like something I chose, not forced."