As someone new to Keto, it can be confusing and challenging to know which vegetables are compatible with keto.
Some vegetables, like tomatoes, depend on portion control to thrive; we cannot imagine life without marinara sauce, salsa and BLTs that fit within the Keto diet, so in this article, we will provide everything you need to know when adding tomatoes into your Keto diet plan.
Additionally, take a look at other types of nightshades to determine whether or not they are Keto-friendly.
What Is Keto? Before we jump into discussing nightshades and tomatoes, let’s quickly go over what Keto means.

Keto Diet is a low-carb, high fat and moderate protein diet designed to promote ketosis – where your body begins burning fat for energy instead of carbs.
Ketosis can bring many advantages. It can aid in weight loss by burning stored body fat more effectively, and improve insulin and blood sugar control in those suffering from Type 2 Diabetes. Many also report that following the Keto diet helps significantly decrease appetite.
To truly experience all of the advantages of Keto diets, it is necessary to limit net carb intake to 5 percent or less of daily calories (net carbs are defined as total carbohydrates minus indigestible fiber and food-specific sugar alcohols (such as isomalt, maltitol and polyglycitol as well as sorbito and xylitol) that have been removed).
Vegetables that only contain 5 grams of net carbs per serving might seem low-carb but could actually consume a significant portion of your daily allowance when following a Keto diet.
What Are Nightshade Vegetables? mes Tomatoes belong to a class of vegetables known as nightshades. Their Latin name, Solanaceae, describes their plant family. There are numerous varieties of nightshade plants; most can’t be eaten as food however; belladonna (deadly nightshade) could cause powerful effects of sedation and could even prove fatal if eaten directly.
All nightshades contain alkaloids, compounds known to affect eating. Due to these alkaloids, some people may not be able to enjoy nightshades very much.
Alkaloids found in nightshades serve as a natural defense system against insects. Their bitter taste deters insects while possessing some insecticidal properties.
Belladonna alkaloids have long been used as an effective means of producing sedative medication.
There are certain nightshades we thoroughly enjoy eating, so rest assured that they do not contain enough alkaloids to cause harm; most people can include these specific nightshade vegetables in their diet without issue.
Nightshades are widely utilized as food items. Common applications for nightshades in food include:
Tomatoes: Tomatoes are an integral component of cuisines worldwide, from Mexican and Italian dishes to French, Spanish and Greek fare. Not only are tomatoes used as ingredients in various dishes – like Mexican cuisine – they’re also featured as sandwiches fillers as well as sauces, dips, soups and casseroles!? Tomatillos: Tomatillos are small green cousins of tomatoes which often produce similar flavour profiles when processed and used as part of sauces and dishes. Potatoes: Potatoes are starchy tuber vegetables which can be cooked, baked, fried or mashed to provide an accompaniment for nearly every food item on your menu. Sweet potatoes do not qualify as nightshades. Peppers: All peppers – bell peppers as well as various varieties of chili peppers – fall under this classification; milder varieties can even be eaten raw or cooked as vegetables. Hotter peppers can add heat and spice to food items. Hot peppers can even be used to create spicy hot sauce. Keep in mind, however, that neither peppercorns nor black pepper are nightshades. Goji Berries: Goji berries (also known as wolfberries) are tart, antioxidant-rich fruits commonly added to smoothies. Eggplant: Eggplant is a purple-skinned vegetable often used in Mediterranean and Asian food preparation. When cut thinly it makes an excellent base for eggplant parmesan dishes as well as delicious stir fries that bring its distinctive flavors alive!
Ashwagandha, an adaptogenic supplement, is also a nightshade like tobacco. Since peppers are nightshades as well, their seasonings like red chili powder, paprika, cayenne powder and chili powder also count.
Fun fact about nighthades We don’t exactly understand where the term “nightshade” originated. Many believe that “nightshade” was first applied to some of the more harmful species from Solanaceae family (such as belladonna) due to their harmful side effects and has stuck ever since; or possibly because nightshade flowers bloom in the evening.
Are Tomatoes Keto Compatible??
Are tomatoes Keto-friendly? Yes, when consumed in moderation.
Example: One quarter-inch-thick slice of sandwich contains only 1 gram of net carbs; however, an entire tomato offers five grams net carbohydrates – an astonishing difference.
Be mindful when using canned tomatoes in dishes or soups as their carbs can quickly add up; one cup of diced canned tomatoes contains 4 grams of net carbs.
Care should also be taken when purchasing tomato-based products such as ketchup and pre-made spaghetti sauce, which often contain added sugars (and more than you think in terms of net carbs). Therefore, look out for sugar-free or Keto-friendly varieties, and be sure to read labels carefully when purchasing these products.
Are There Any Nightshades That Are Keto Friendly?
By perusing the list of nightshades that are edible, it may be possible to determine which are high or low in net carbohydrates. Certain nightshades may be keto-friendly while others should not be eaten due to their abundance of net carbohydrates.
Peppers – bell and hot peppers alike – make an excellent keto snack. A medium bell pepper has only 4 grams of net carbs while 2 inch long jalapeno peppers offer only 1 gram net carbs!
Eggplant can also fit within a Keto diet as long as its portion sizes are managed properly. A medium-sized full-sized eggplant contains 16.4 grams net of carbs; to keep carb consumption within acceptable levels for Keto eating, consider splitting up an eggplant into several servings to lower its net carb count and keep its total amount in check.
Potatoes may not be suitable for Keto diets unless you are willing to consume most of your net carbs in one small serving; one cup provides 29g net carbohydrates while a medium-sized potato offers 26 grams net carbohydrates.
Goji berries should also not be included on a Keto diet as a 1/4 cup serving contains 14 net grams of carbs – enough to absorb all your daily intake!
Tomatillos are also keto-friendly; each tomatillo contains only 1 gram of net carbs!?
Who Should Avoid Nightshades? mes Some individuals may feel better by limiting their exposure to nightshades and foods containing nightshades, as these plants contain alkaloids which could irritate sensitive individuals.
People suffering from autoimmune diseases that weaken their immune systems could be particularly sensitive to nighttime smells that trigger an immune reaction in them, often manifested through skin rashes, digestive issues, itching or congestion.
Many individuals living with autoimmune disorders have reported experiencing relief after cutting nightshades out of their daily diet. Unfortunately, due to limited research into this area – most evidence that nightshade-free diets can relieve symptoms associated with autoimmune conditions comes from personal experience rather than studies conducted on them.
People without autoimmune disorders have reported sensitivities to tomatoes in particular; these foods often trigger heartburn. Most evidence supporting nightshade avoidance as a means to alleviate autoimmune disease symptoms comes from anecdotal reports or research regarding Autoimmune Protocol diet plans that include temporary removal of nightshades from one’s diet (AIP diet plans).
If you experience symptoms of allergy or heartburn after taking tomatoes or any other vegetables that contain nightshade, you may wish to reduce or even discontinue their consumption for a time period. One approach could be eliminating trigger food for two weeks before gradually adding in small amounts and monitoring symptoms; if an allergic reaction develops then consider increasing that food gradually over 2-3 days; if none occurs you might consider including it back into your diet plan.
Takeaway
Nightshade plants form an extensive plant family that contains popularly used vegetables like tomatoes and peppers, potatoes and eggplant. While potatoes contain too many carbs for inclusion on a Keto diet plan, peppers tomatoes and eggplant all qualify if portions are strictly adhered to.
Keto-friendly tomatoes can be used in numerous recipes including pizzas, pasta, salsas and sandwiches as well as casseroles, soups and salads. Fresh tomatoes may provide an effective way to avoid added sugars in pizza sauce and spaghetti sauce while keeping serving sizes under control! Remember: every ingredient counts!


