Today someone asked me why I advise against peanut butter for the keto lifestyle. It is made of nuts, right? And aren’t nuts okay to eat on keto? Well, not quite. You see, the peanut is not a nut at all, but a legume. And legumes in general are best avoided, and not just because of their higher carb count.
Legumes are rich in saponins, lectins, phytates and trypsin inhibitors, the so-called ‘anti-nutrients’. These are natural components of the plant that are designed to protect it from consumption by insects and other predators, but for humans as well they can cause problems with the correct absorption of good nutrients.
All plants (including grains, nuts and seeds) have saponins and lectins, but they are usually concentrated in the seeds. And beans are the seeds.
So why is this bad?
Legumes can be problematic for the human body for a number of reasons. They are difficult to digest and also have the potential to feed the bad bacteria in our stomach. Because of their interaction with our intestinal barrier, they can even create holes in the surface of the membranes of our digestive tract, making our intestinal cells permeable. This is also called leaky gut.
Leaky gut occurs when the cells that form the close bond between the intestinal walls are damaged. Then molecules that normally can’t get into the body can be let through. This then causes inflammation.
Furthermore, other anti-nutrients, such as phytic acid, bind to minerals and then make it difficult to absorb them. Phytic acid inhibits the digestive enzymes amylase, trypsin and pepsin.
In short, legumes, and this includes peanut butter, do not belong in a well formulated keto diet. But don’t worry: real nuts and nut butters are perfectly fine to eat in moderation.
Would you like to learn which foods are suitable for keto? Take a look here: