What’s in a Jar of Peanut Butter?

by Amy Wood

By Marie Spano, RDNpeanut-butter

If you’ve ever looked at the ingredients in a jar of peanut butter, you may wonder why some brands contain more than just peanuts. Why do some add salt, sugar and oil? Is natural peanut butter healthier?

Ingredients are listed on food labels in descending order by weight.[1] Take a look at any jar of peanut butter, regardless of the brand, and you’ll notice the first ingredient is peanuts! That’s because the U.S. Food and Drug Administration requirements specify that peanut butter must contain at least 90% peanuts by weight while all other ingredients in peanut butter must equal less than 10% by weight.[2] Artificial flavors, artificial sweeteners, colors additives and chemical preservatives are not allowed in peanut butter.

The other ingredients in some regular peanut butters may include seasonings, typically just salt and sugar, to enhance the flavor and oil, which acts as a stabilizer helping prevent the oil naturally present in peanut butter from separating and rising to the top of the jar. This small amount of added oil increases shelf life and helps maintain the characteristic smooth and creamy texture of peanut butter that people love. And though oil stabilizers make up just 1-2% of peanut butter by weight,[3] there’s a considerable amount of confusion surrounding them.

There are a few different types of oil used in peanut butter. Palm fruit oil, which is added to some natural peanut butters, is not hydrogenated, does not contain trans fat and approximately half of the fat in palm fruit oil is from saturated fat. Fully hydrogenated vegetable oil found in some regular peanut butters also contains saturated fat but is trans fat free. And, partially hydrogenated oils, which contain trans fats, are rarely used.[4] Regardless of the type of oil added and whether its natural or regular peanut butter, all peanut butter must contain zero grams of trans fats per serving. However, here’s where the controversy lies. If partially hydrogenated oils contain trans fats, how do they have zero grams of trans fats?

A U.S. Department of Agriculture study examined 11 brands of peanut butter, including brands labeled as “natural,” major store brands and paste freshly prepared from roasted peanuts. No detectable trans fats were found in any of the samples. In fact, the level of trans fat in two tablespoons of peanut butter with partially hydrogenated oil is 156 times less than the very minimum amount of trans fats per serving (0.5 grams) necessary for trans fats to be listed on the Nutrition Facts panel.* And therefore, a person would have to eat about 11 one-pound jars of peanut butter made with partially hydrogenated oil to consume 0.5 grams of trans fats!

pbspoonLike the peanuts it is made from, peanut butter is an inexpensive source of plant protein, providing 8 grams in two tablespoons. Peanut butter is also an excellent source of vitamins, minerals, and plant-based compounds that are important for good health. So rest assured, you can feel good about digging into your favorite jar—whether it’s creamy or crunchy, natural or regular—to reap the nutrition benefits from peanut butter. And, no matter your preference, there are plenty of options on the peanut butter aisle to choose from.

*In the study, the detection limit was 0.01 percent of sample weight. Given that the trans fatty acid content of the partially hydrogenated oil used in peanut butter at the time of this study was between 5-8% of the total fat content, a typical 2 tablespoon (32-gram) serving of any of the tested brands containing 1.5% of an oil stabilizer with 6% trans fats could have contained a little over 0.0032 of a gram of trans fats without being detected.[5]


[1] Guidance for Industry: A Food Labeling Guide (6. Ingredient Lists). Department of Health and Human Services. http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/LabelingNutrition/ucm064880.htm

[2] Peanut Butter; Amendment of Standard of Identity. DEPARTMENT OF HEALTH AND HUMAN SERVICES. Food and Drug Administration. 21 CFR Part 164 [Docket No. 93N–0473]


[3] Direct Food Substances Affirmed as Generally Recognized as Safe. Subpart B – Listing of Specific Substances Affirmed as GRAS. 21CFR184.1555


[4] Sundram K, Sambanthamurthi R, Tan Y. Palm fruit chemistry and nutrition. Asia Pacific J Clin Nutr 2003; 12(3):355-362.

[5]Sanders TH. Non-detectable levels of trans-fatty acids in peanut butter. J Agric Food Chem 2001;49(5):2349-51.


Marie Spano, MS, RD is one of the leading sports nutrition and nutrition communications experts in North America. Marie is a highly sought after advisor to some of the most respected food and nutritional supplement companies in American and Europe. She has formulated products, developed marketing materials and provided media communications exposure through TV, radio and public speaking. Marie is also an accomplished researcher with regular contributions to popular press magazines such as Muscle & Fitness Hers and FitnessRx for Women, as well as industry publications.  She is the co-editor of a forthcoming Human Kinetics textbook on Sports Nutrition.


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