Fact-checked by Dr. Anthony Gustin, DC, MS.
Written by Emily Ziedman
Butternut squash is a fall season classic. Stick it in the oven, drizzle it with butter or coconut oil, cook until lightly brown, and you’ve got yourself a delicious meal or side dish.
Or do you?
When it comes to the ketogenic diet, higher-carb veggies could derail your keto macros and kick you out of ketosis.
Due to the net carb count, you may assume that you have to avoid butternut squash dishes — but don’t delete all those squash recipes from your keto meal plan just yet.
A quick look at the nutrition information and you’ll find that butternut squash provides a rich array of nutrients like vitamin A, vitamin C, beta-carotene, and dietary fiber.
So does this somewhat starchy gourd deserve a place in your keto lifestyle? Read on to learn more about the benefits of butternut squash, its total carb count, and how it may, in fact, work in your low-carb diet
Butternut squash is a winter squash with a beautiful orange/yellow color.
While summer squash tend to have thinner, edible skin, winter squash like butternut squash have a thicker, inedible skin. Other types of winter squash include pumpkin, acorn, and spaghetti squash.
And despite its name, you can usually find butternut squash all year long.
Craving butternut squash soup in the spring? No problem. This is because, although harvested in the late summer and fall, you can store this hearty vegetable for months at a time.
In fact, some suggest that the nutrient-density of certain squash increases as you store them.
Even without extended storage butternut squash is full of nutrients. It’s an excellent source of vitamin A, with just one cup of cubed squash containing nearly 100% of your daily needs.
It also provides 50% of your daily vitamin C requirements and 21 grams of fiber.
And that yellow-orange color of the meat of the squash comes from its abundance of carotenoids, including both beta-carotene and alpha-carotene[*].
Now for the bad news.
Butternut squash is higher in carbohydrates — starchy carbs to be specific.
Because of this, you want to be careful when adding it to your ketogenic diet. However, before you write it off completely — let’s take a look at some of the benefits of this winter squash.
#1: Rich in antioxidants
Your body creates oxidative stress every day as a regular part being alive. Stressors like air pollution and carcinogens can create oxidation in your body, but simple processes like breathing and eating also have an impact.
That’s what antioxidants are for.
Antioxidants from food come in to combat this stress and bring balance to your system. The key is to consume enough antioxidants to maintain this balance so that oxidation doesn’t overextend its reach and create damage like inflammation and tissue destruction.
An antioxidant is any compound that helps to calm down the oxidation that’s happening in your body. They come in many shapes and sizes, from vitamins and minerals to macronutrients like polysaccharides.
Butternut squash has also been studied for the antioxidant value of its polysaccharides. An in vitro study showed that antioxidants from butternut squash had significant free radical quenching activity[*].
#2: Enhances Immunity
Butternut squash is an immune-enhancing powerhouse. Aside from the rich array of vitamins and minerals in most vegetables, butternut squash has a few aces up its sleeve.
The carotenoids, as antioxidants, protect your cells from oxidation. This alone enhances immune function as it keeps things moving smoothly for your body on a cellular level[*].
Carotenoids may also increase your immune cell activity to help protect you against viruses.
One study showed that supplementation with beta carotene increased natural killer cell activity in elderly men. Natural killer cells are immune cells that fight off viruses and tumors, suggesting that beta carotene may be helpful for the treatment of viruses and tumors[*]
Many people claim that dosing yourself with vitamin C is a cure-all when it comes to immunity. This theory most likely comes from the fact that several immune cells need vitamin C to function properly, and a deficiency can lead to weakened immunity.
There aren’t many good studies that can prove that vitamin C alone can kick the common cold.
However, the importance of vitamin C for optimal immune health is well established. When it comes to treating and preventing the common cold, studies support the importance of vitamin C as a major player[*].
Along the lines of immunity, butternut squash also contains specific compounds that may have anticancer activity.
One study looked at the effect of moschatin, a protein found in butternut squash, on melanoma cells in vitro.
The study found that the protein had an anticancer effect on the cells, inhibiting melanoma growth. Moschatin is known as a ribosome-inactivating protein, meaning it inhibits the production of proteins. This activity could explain its anticancer effects[*].
The beta-carotene in butternut squash may also exhibit anticancer activity. As mentioned before, carotenoids can increase the activity of your immune cells.
Over 30 epidemiological studies have shown a correlation between a beta-carotene-rich diet, high levels of beta-carotene in the blood, and a lower incidence of cancer. This could be because of an increase in immune activity[*].
#4: Lowers Blood Pressure
Potassium is one of the most essential nutrients for balancing blood pressure. Butternut squash is a fantastic source of potassium, containing about 16% of your daily requirement in just one cup.
Potassium affects your blood pressure by balancing the effects of sodium. The more potassium you consume, the more sodium you excrete in your urine. Since the Standard American Diet tends to be sodium-heavy, getting enough potassium to keep the balance is essential[*].
Potassium also helps your blood vessels to relax, allowing more gentle blood flow throughout your body. When your blood vessels are tense, they contract, and blood flow becomes more rapid, i.e., high blood pressure[*].
A meta-analysis was done of 33 randomized controlled trials with over 2600 participants to assess the correlation of dietary potassium and blood pressure.
Researchers found that low potassium intake had a strong positive correlation with high blood pressure, and suggested that patients should consider more dietary potassium as prevention and treatment for hypertension[*].
#5: Great For Skin
When it comes to skin health, vitamin A may be the single most powerful nutrient you can consume. And butternut squash is an excellent source of vitamin A.
Vitamin A plays a key role in regulating skin cell proliferation — aka, the rate at which cells divide and grow. It’s particularly good at creating a cell type called epidermal keratinocytes, which account for about 90% of the outermost layer of your skin[*].
Vitamin A is also responsible for the proliferation of another cell type, dermal fibroblasts. Dermal fibroblasts live in the dermis layer of your skin and are responsible for generating connective tissue and assisting in the recovery of your skin from injury[*].
In addition to cell proliferation, vitamin A also protects your skin from UV radiation.
A little UV radiation from natural sunlight is fine — and even good for you. But overexposure comes with consequences.
The protective effects of vitamin A come from two mechanisms; enhancing cell turnover (so there’s less of a chance for cancerous cells to take over); and inhibiting the expression of enzymes that would degrade your skin[*].
Vitamin C also plays a role in protecting your skin from UV radiation. As an antioxidant compound, it protects your cells from the oxidative stress that UV light may pose[*].
Vitamin C also helps your body produce collagen, a connective tissue compound that gives your skin a supple firm look and feel. Many people claim that more collagen can make your skin look younger and decrease the visibility of wrinkles[*].
#6: Hair Health
Maintaining a healthy head of hair may not seem like the most important marker for health, but hair health can be a pretty accurate clue as to what’s happening inside your body.
Vitamin A is essential for the health of your hair and scalp. Your scalp contains sebaceous glands that release an oily substance called sebum. Vitamin A helps to balance the production of sebum, the overproduction of which can lead to scalp inflammation and dandruff, and ultimately hair loss[*].
Vitamin A deficiency may even cause hair loss, according to one rodent study[*].
#7: Supports Lung Health
Several studies have looked at the connection between beta-carotene and lung health.
One study looked specifically at exercise-induced asthma (EIA) and the potential therapeutic effects that beta-carotene may offer.
Asthmatic volunteers were given either a placebo or 65 mg of beta-carotene before exercise.
After the workout, 100% of the placebo group experienced EIA, while only 47% of the beta-carotene group reported symptoms. Researchers gathered that this might be because of the antioxidant effect of beta-carotene on lung tissue[*].
In addition to asthma, beta-carotene has also been shown to support those with chronic obstructive bronchopulmonary diseases (COPD)[*].
The powerful antioxidants from vitamin C and beta-carotene may also protect against damage from smoking and air pollution[*].
As you can see, butternut squash is loaded with nutrients that could have a positive impact on almost anyone’s health.
The only downside to this vegetable is that it’s pretty high-carb. One cup of butternut squash has 16 grams of carbs. Not terrible. Unless you’re trying to keep your carb count below 50 grams per day[*].
If you’re one of the lucky people who can stay in ketosis with higher carbs, then you should absolutely think about incorporating modest amounts of butternut squash into your diet.
However, if you’re carb sensitive, you may want to moderate the amount of butternut squash you eat. For instance, 4 grams in 1/4 cup isn’t too bad, but you may not want to go beyond that.
Depending on what type of ketogenic diet you’re following, you may also be able to add in butternut squash during carb refeeding.
For instance, if you’re following a cyclical keto diet where you have higher carb consumption one or two days a week, add in some butternut squash on your higher carb days.
Likewise, maybe you follow a targeted ketogenic diet where you increase carbs in the hours before and after your workouts. You could use butternut squash as a pre-workout fuel to help keep you going while optimizing your ability to expend energy.
Although butternut squash may not be a mainstay in your keto diet, it certainly can find its place here and there. Remember — everything in moderation.
If you are very sensitive to carbs and concerned that butternut squash will kick you out of ketosis, then you’ve got options.
Eat Other Squashes
You could eat other lower-carb squashes like zucchini and summer squash. These squashes have a thinner skin and lower starchy carb content. They’re also versatile and delicious.
Summer squash is a great source of vitamin C and beta-carotene, just like its winter squash counterpart. And one cup of chopped summer squash only has 2.5 grams of net carbs[*]
Zucchini contains around 40% of your daily needs of vitamin A, and has only two net carbs per cup[*]. These squashes are higher in water and lower in starch than winter squash, so they can even help you stay hydrated while keeping your carb count down.
Eat It With Carb Balancing Foods
One way to enjoy the benefits of butternut squash without kicking yourself out of ketosis is by making it a part of a well-balanced meal.
Taking down a half a squash on your own is probably a bad idea if you want to stay in ketosis — but you don’t need to eat that much to reap the health benefits. When it comes to butternut squash in keto-friendly meal plans, it’s all about serving size.
Try adding butternut squash to one-pot meals that are rich in fat and protein.
A great example would be a coconut cream soup, with lots of delicious low-carb vegetables and chicken or beef. The coconut base will provide a healthy serving of fat, and the meat will balance it out with protein.
If your meal is high-fat and protein heavy then the small amount of butternut squash won’t make as big of an impact on your blood sugar than if you had it alone.
On that note — many of the nutrients in butternut squash are fat-soluble. This means your gut only absorbs them if you eat them along with fat.
So even if you do have a high tolerance for carbs, adding a little fat along with your squash is always a good idea.
The answer is — it can be. It all really depends on your carb tolerance, your goals, and your activity level.
If you’re someone who can eat 100+ carbs a day and stay in ketosis, then you may be able to enjoy butternut squash without any worries.
However, for the carb sensitive (which is a lot of us), you may need to take care when preparing meals with butternut squash. Not to say you can’t enjoy it at all, but it isn’t going to be a mainstay like your leafy greens and brussels sprouts.
If you’re unsure about your carbohydrate tolerance and how many carbs you need per day then check out our Keto Calculator.
This will help you determine what the right macronutrient ratio is for you, and whether or not you want to stay on the moderate side of winter squash.