Peanuts can be a controversial topic in the keto world, with entrenched "for" and "against" camps scattered throughout the nutritional landscape. We frequently see very vociferous volatility around the subject of peanuts (and peanut butter), and so we wish to shed some light on the subject for those who are confused or caught in-between the various peanut-related opinions.
Important Note: If you're currently eating peanut butter and the ingredients list contains more than "peanuts" or "peanuts and salt" we strongly recommend switching to a natural one.
What's the Big Deal?
There are some pro and con arguments that are frequently made in regards to peanuts. They usually go as follows:
- It has a low insulin impact
- It is low on the glycemic index
- It is relatively low in carbohydrates
- "I don't have a problem with it, so I'll keep eating as much as I want and you can, too."
- The omega-3/omega-6 ratio is far from ideal
- It is inflammatory
- It is a legume, not a nut
- "PEANUTS ARE THE DEVIL!!!!"
Which Answer Is (More) Right?
It is true that peanuts have a fairly low impact on insulin, is low on the glycemic index, and is relatively low in carbohydrates. These are some of the primary qualities we look for in low-carb and keto-friendly foods! It is not true, however, that because one person might eat them without issue everyone, therefore, may also eat them without issue. The truth is that there are many people who notice increases in inflammation, bloat, and auto-immune flares when they consume peanuts, even in fairly small quantities. For these persons, even though the other points in the pro column may be true, they still must eliminate peanuts to reach their full ketogenic potential.
So, what about the flip side?
It is also true that the ratio of omega3 to omega6 fatty acids in peanuts is less than ideal. Historically, human beings evolved eating foods with an omega3 to omega6 ratio of 1:1, and it's widely acknowledged that imbalances in that ratio can lead to health problems. Modern diets tend to be especially high in omega6 fatty acids and too low in omega3. All of this leads us to acknowledging that it is also true (and for the reasons just laid out) that peanuts tend to be inflammatory foods. Peanuts also happen to be a fairly high allergenic, which is another indication that may point toward potential problems. Of course, it is also true that peanuts are not actual nuts, but are legumes (aka, a member of the bean family). Beans are typically excluded on ketogenic protocols due to the presence of several phytochemicals, like lectins and oxalates, that are inflammatory or cause hormonal imbalances or other internal issues, although that is not universal. Green or string-style beans, for example, are generally approved despite being members of the legume family because what is actually consumed is mostly the fibrous, nutrient-filled pod, and almost no actual bean or pea.
Even so, we can't really agree that peanuts are "the devil" or inherently bad for a low-carb lifestyle because they do have redeeming qualities (mentioned above) and many ketonians eat them regularly with no issue. While that in itself doesn't make them appropriate (and we don't tend to promote an "if it fits your macros" approach to the lifestyle), there are some other factors we must also consider before making any peanut pronouncements.
- Peanuts have an insulin index of 11
- For comparison, steak (which is indisputably keto friendly) has an insulin index of about 35
- Peanuts have a glycemic index of 14
- Bran fiber, which many people automatically deduct from their totals, has a glycemic index of around 30
- Peanuts have 16g total carbs per every 100g (3.5 oz)
- Almonds have 22g total carbs per every 100g (3.5 oz)
- Macadamia nuts have 14g total carbs per every 100g (3.5 oz)
- Peanuts are 33% omega-6 fatty acids (inflammatory), and only contain a trace amount of omega-3 fatty acids (anti-inflammatory)
What Does It Mean?
When it comes to peanuts, the evidence is kind of a mixed bag. The pros and cons both contain some important points, but neither side of the ledger heavily outweighs the other. Thus, it is our considered opinion that peanuts fall into what we typically call a "grey" area. You will find that there are many foods that are similarly grey; they don't really neatly fit into a hard "yes" or "no" category, and therefore the issue of whether or not to include them in your low carb diet is a matter of judgment (like added bulk fibers, or the string beans we mentioned earlier).
So, should you eat them? Maybe, but it depends on you. If you like peanuts (assuming you're not allergic), and peanuts don't stop you from reaching your goal, eat them! If you don't like peanuts, or peanuts stop you from reaching your goal, then avoid them. When it comes to grey area foods, knowing your own body (its needs and its limitations) is crucial, and paying attention to how it reacts to what you eat should be your ultimate guide in this matter.