Updated: Sep 12
Or, more accurately, what you can't eat.
If you've ever been on a keto diet, or know someone who has, you know that you have to spend a lot of time Googling and calculating and re-Googling certain foods to determine if they fit into the macronutrient balance you need in order to enter or maintain "ketosis," the state under which your body burns fat for fuel.
And you've also likely faced some very deep, very personal questions about yourself, such as the one you're addressing right now: "Is peanut butter, one of the most delicious foods on the planet, in fact, keto?"
Maybe you even fear the truth: "If peanut butter isn't keto, then what is life in ketosis anyway?"
Peanut butter is clearly high in fat—if you buy the natural kind then you're familiar with that pool of the stuff sitting atop the solids. (Yeah, that's fat!) And the keto diet prizes fats in such a way that some suggestions recommend you consume 70 percent of your daily calories from fat.
So, because peanut butter is high in fat and also naturally low in carbohydrates, of which you're required to eat very little of on a ketogenic diet, then you're in the clear, right?
"Peanut butter can be a part of a keto diet since it contains mostly fats and protein with very little carbohydrates," says Dara Godfrey, M.S., R.D., a registered dietitian in New York City.
Except, before you grab a soup spoon and start digging straight into the jar (you know you do it). there are a few important details to consider.
Is peanut butter keto?
Yes, but there's a catch.
On a ketogenic, the caloric breakdown usually falls in place as so: 60 to 80 percent of your daily calories come from fat, 20 to 30 percent from protein, and the rest from carbs. (This usually amounts to little more than 30 grams of carbs daily. And yeaaaaah that's practically nothing.)
Peanut butter is high-fat, low-carb—unless you're buying flavored peanut butters that load up on one threat to ketosis: sugar.
"The keto diet is all about staying in the nutrient ranges, so avoiding added sugars is key," says Jessica Crandall Snyder, R.D.N., of Vital RD in Denver and spokesperson for the Academy of Nutrition and Dietetics.
So fair warning: "Most peanut butters on the market add sugar into their product," says Dara Godfrey, MS, RD, a registered dietitian in New York City.
If you're serious about keto, make sure you're reading labels for peanut butter with no added sugars.
Important note: Peanuts naturally contain sugars so it's incredibly difficult, if not impossible, to find a peanut butter with no sugar—it's the added sugars that you need to watch out for.
What kind of peanut butter is best for keto?
She points out that in a two-tablespoon serving, most natural peanut butters contain 6 to 7 grams of carbohydrates. Subtract the carbs that come from fiber, and you're looking at 2-4 grams of net carbs. "Most of the carbohydrates it does contain comes from fiber carbs, which break down much more slowly in our digestive tract than carbohydrates coming from sugars," Godfrey says.
Another note about choosing a keto-friendly peanut butter: Most "low fat" or "reduced fat" brands add in sugar, Godfrey says.
Are nut butters, in general, keto?
"Nut butter is high in fat and protein and suitable on a keto diet. Same with peanut butter, almond butter, and sunflower seed butter," says Crandall Snyder.
"For me, choosing a variety of nut butters is optimal, since different nuts contain different beneficial vitamins and minerals," Godfrey recommends. "Almonds have calcium, cashews are rich in iron and magnesium, [and] walnuts are high in omega-3s."
Finally, we hate to break it to you, but you're going to want to pass on the Nutella—even though it does contain hazelnuts. Those 19 grams of carbs in every two-tablespoon serving aren't going to help you stay in ketosis.