What Veggies Are Not Allowed on Keto? A Comprehensive Guide to High-Carb Vegetables

November 2, 2025 •

4 min read

Did you know that a single medium potato can contain over 30 grams of carbohydrates, potentially using up a beginner's entire daily carb allowance on a ketogenic diet? To successfully reach and maintain ketosis, understanding what veggies are not allowed on keto is crucial for navigating your food choices and ensuring your hard work pays off. By focusing on low-carb options, you can still enjoy nutrient-dense vegetables without derailing your diet.

Quick Summary

Starchy and root vegetables are typically too high in carbs for a strict keto diet. Avoiding vegetables like potatoes, corn, and peas is essential for managing your daily carbohydrate limit and maintaining ketosis effectively.

Key Points

Avoid Starchy Roots: Steer clear of vegetables like potatoes, sweet potatoes, and parsnips, as their high starch content can easily exceed your daily carb limit.
Limit Legumes and Grains: Items like corn and peas are high in carbohydrates and should be avoided on a standard ketogenic diet.
Watch Winter Squashes: Certain varieties such as butternut and acorn squash are higher in carbs and need to be strictly portioned.
Prioritize Above-Ground Veggies: Focus on non-starchy, leafy greens and cruciferous vegetables, which are lower in carbs and rich in nutrients.
Track Your Intake: Even lower-carb vegetables contribute to your total daily carb intake, so tracking is still necessary to maintain ketosis.
Seek Low-Carb Alternatives: Use clever substitutes like cauliflower mash or zucchini noodles to replace high-carb favorites without compromising your diet.
Mindful Moderation: Use higher-carb flavor enhancers like onions and carrots sparingly to keep your carb count in check.

The ketogenic diet, commonly known as keto, is a low-carbohydrate, high-fat eating plan that forces the body into a metabolic state called ketosis. In this state, your body becomes incredibly efficient at burning fat for energy instead of carbs. For this process to work, carbohydrate intake must be strictly limited, often to as little as 20–50 grams of net carbs per day. While many vegetables are a staple of a healthy diet, some are too high in carbs to fit into this restrictive eating plan.

The High-Carb Offenders: Starchy and Root Vegetables

The fundamental rule for choosing vegetables on keto is to avoid those that are high in starch. Starch is a complex carbohydrate that, when digested, breaks down into glucose, which can raise your blood sugar and knock you out of ketosis. Root vegetables, which grow underground, are the most common source of high-carb starches.

Potatoes and Sweet Potatoes

Potatoes are one of the most prominent high-carb vegetables to avoid on a keto diet. They are a classic example of a starchy vegetable, with a single medium white potato containing over 30 grams of carbs. This amount alone can consume or even exceed a dieter's daily limit. Sweet potatoes and yams are similarly high in carbohydrates and should be avoided or consumed only in minimal amounts on a targeted or cyclical keto diet. The significant carb load and glycemic impact of these tubers make them a definite no-go for strict keto.

Corn and Peas

Corn is a common starchy vegetable that should be avoided on keto. As a grain, it is particularly high in carbohydrates, with one cup of corn kernels containing nearly 20 grams of total carbs. Peas, while often enjoyed as a vegetable, are technically legumes and are also high in carbohydrates. Just one cup of green peas can contain over 15 grams of carbs, making them unsuitable for regular consumption on a keto plan.

Parsnips and Beets

These root vegetables also fall into the high-carb category. Parsnips, often roasted for their sweet flavor, are too starchy for a ketogenic diet. Beets, though nutrient-rich, are also higher in natural sugars and should be limited or avoided altogether, depending on your daily carb allowance.

Winter Squashes

While some squashes are low-carb, many winter varieties like butternut and acorn squash are too high in carbohydrates for a ketogenic diet. These are often sweeter and starchier than their summer counterparts. For instance, a cup of cooked butternut squash contains approximately 16 grams of carbohydrates.

Other Limited Vegetables

Some vegetables, while not as carb-dense as potatoes or corn, still require careful moderation. Onions and carrots, for example, contain more carbs and sugar than leafy greens. While small amounts used for flavoring are generally fine, large portions can add up quickly and push you over your daily limit.

The Carb Count: High-Carb vs. Keto-Friendly Veggies

Understanding the carb density of different vegetables is key to making informed choices. Here is a comparison of common high-carb and keto-friendly options based on their approximate net carb content per 100g serving.


Vegetable	Net Carbs (per 100g)	Notes
High-Carb Vegetables
Potato	~15g	High starch content; avoid on strict keto.
Sweet Potato	~17g	High starch content; avoid on strict keto.
Corn	~16g	A grain, very high in carbs; avoid.
Peas	~9g	Legume, higher carb count; limit or avoid.
Parsnip	~13g	High starch content; avoid.
Butternut Squash	~10g	Moderately high; requires strict portion control.
Keto-Friendly Vegetables
Spinach	~2g	Very low-carb, ideal for keto.
Broccoli	~4g	Low-carb, versatile option.
Cauliflower	~3g	Excellent low-carb substitute for starches.
Zucchini	~3g	Great for 'zoodles' and other alternatives.
Bell Peppers	~4g (red)	Low-carb; can be used in moderation.
Asparagus	~1g	Very low-carb, great for keto meals.

Navigating Vegetables on a Keto Diet

To ensure your vegetable intake remains keto-friendly, it’s best to prioritize options that are grown above ground. These are typically lower in starch and carbohydrates.

Keto-Friendly Vegetable Choices

Leafy Greens: Spinach, kale, arugula, and romaine lettuce are excellent choices. They are extremely low in carbs and provide a high amount of fiber and nutrients.
Cruciferous Vegetables: Broccoli, cauliflower, Brussels sprouts, and cabbage are highly versatile and low in carbs. Cauliflower, in particular, can be used to create keto-friendly versions of rice, mashed potatoes, and pizza crust.
Summer Squashes: Zucchini and yellow squash are very low in carbs and can be used to make vegetable noodles or add bulk to dishes.
Mushrooms: A great low-carb option that can add a savory, meaty texture to your meals.
Peppers: Bell peppers, especially green, can be enjoyed in moderation. Hot peppers like jalapeños are also fine.

Tips for Success

Embrace Low-Carb Swaps: Replace high-carb starches with clever alternatives. Instead of mashed potatoes, try mashed cauliflower. Use zucchini noodles instead of pasta.
Use Moderation: Vegetables like onions and carrots should be used sparingly as a flavoring agent rather than a main component of a dish.
Track Your Intake: Because all vegetables contain some carbohydrates, it's wise to track your net carb intake to ensure you stay within your daily keto limit.
Prioritize Fiber: Fiber helps fill you up and is subtracted from total carbs to calculate net carbs. Low-carb vegetables are typically high in fiber, which is a big win on keto.

Conclusion: Making Informed Choices for a Successful Keto Diet

Successfully adhering to a ketogenic diet requires a clear understanding of carbohydrate sources, and vegetables are no exception. By knowing what veggies are not allowed on keto—namely starchy root vegetables, legumes, and certain squashes—you can avoid common pitfalls that can knock your body out of ketosis. Instead, fill your plate with delicious, nutrient-dense, low-carb options like leafy greens, broccoli, and zucchini. With careful planning and smart substitutions, you can enjoy a wide variety of flavors while staying on track with your nutritional goals.

For more detailed information on specific food carb counts, you can consult the USDA FoodData Central.

Frequently Asked Questions

Starchy vegetables like potatoes and yams are not suitable for a keto diet because they are very high in carbohydrates. When consumed, these carbs break down into glucose, which can raise blood sugar levels and prevent your body from entering or remaining in ketosis.

On a standard keto diet with a very low carb limit (e.g., 20-30g per day), potatoes should be avoided entirely due to their high carb content. Some people on cyclical or targeted keto may reintroduce small portions, but this is an exception and requires careful tracking.

Carrots and beets are higher in carbs and sugar than other keto-friendly vegetables. They are best consumed only in strict moderation or as a small part of a recipe, as they can quickly add to your daily carb count.

Corn, which is a grain, is very high in carbohydrates and should typically be avoided on keto. Even small amounts can use up a significant portion of your daily carb limit, making it difficult to stay in ketosis.

Great low-carb alternatives include using mashed cauliflower instead of mashed potatoes, making 'zoodles' (zucchini noodles) to replace pasta, and using cauliflower rice instead of regular rice.

Yes, all carbohydrates, including those from vegetables, count toward your daily total. While low-carb vegetables like leafy greens have minimal impact, it's important to track your intake to ensure you don't exceed your daily carb limit and maintain ketosis.

The safest vegetables to eat on keto are typically those that grow above ground. These include leafy greens (spinach, kale), cruciferous vegetables (broccoli, cauliflower), summer squashes (zucchini), and peppers.

While all vegetables are healthy, the keto diet's primary goal is to limit carbs to induce ketosis. High-carb vegetables, even if nutrient-dense, can impede this metabolic state. Keto prioritizes fat and moderate protein while getting carbs from low-starch vegetables.