What is the most unhealthy vegetable?


When it comes to eating healthy, vegetables are typically considered one of the healthiest food groups. However, not all vegetables are created equal. Some contain higher amounts of sugar, starch, and calories than others. When consumed in large quantities, even vegetables can contribute to weight gain and health problems. So which vegetables should you limit in your diet? Here we analyze nutritional data to determine the most unhealthy vegetables.

Factors that Make a Vegetable Unhealthy

Several key factors contribute to making some vegetables less healthy than others:

High glycemic load

The glycemic load measures how much a food spikes your blood sugar. High glycemic foods cause faster and larger increases in blood sugar levels. Over time this can lead to insulin resistance, weight gain, and diabetes. Vegetables with a high glycemic load include white potatoes, pumpkin, corn, and beets.

High calorie density

Calorie density refers to the number of calories in a given weight of food. Vegetables with a high calorie density provide more calories relative to their serving size. Some examples are corn, pumpkin, avocados, and sweet potatoes. Eating large portions of these vegetables can promote weight gain.

Low nutrient density

Nutrient density describes the amount of nutrients a food contains compared to its calories. Vegetables like iceberg lettuce and cucumbers are high in water and low in nutrients. Eating them provides few benefits compared to the calories they contain.

High sugar content

Many starchy vegetables like corn and sweet potatoes have a high natural sugar content. Frequent consumption can spike blood sugar levels and lead to overeating when sugar crashes occur.

High starch content

Starchy vegetables like potatoes consist almost entirely of starch. Starch breaks down into glucose during digestion, which can adversely affect blood sugar control. Excess glucose is also readily converted to fat.

Low fiber content

Fiber slows digestion, promotes fullness, and helps regulate blood sugar. Vegetables low in fiber include iceberg lettuce, cucumbers, and radishes. The lack of fiber allows food to pass quickly through the digestive system.

Now that we’ve examined the factors that can make vegetables unhealthy, let’s analyze specific vegetables to determine the very worst options.

The Most Unhealthy Vegetables

To identify the most unhealthy vegetables, I compared the nutrient profiles of common vegetables using data from the USDA FoodData Central database [1]. I looked at calorie density, glycemic load, fiber content, vitamins, minerals, and phytonutrients to assess overall nutritional value. Here are the top 5 most unhealthy vegetables based on the results:

1. White Potatoes

White potatoes including russets and Yukon golds are very high in starch with little nutritional value. One medium baked white potato contains:

  • Calories: 161
  • Glycemic load: 33
  • Fiber: 2.8g
  • Vitamin C: 17% DV
  • Vitamin B6: 27% DV
  • Potassium: 26% DV
  • No phytonutrients

This starchy carb source spikes blood sugar and provides far fewer nutrients than other vegetables. Potatoes also contain glycoalkaloids, which may cause digestive issues in sensitive people.

2. Corn

Corn is very high in sugar and starch and low in most nutrients:

  • Calories: 96 per 100g cooked
  • Glycemic load: 75
  • Fiber: 2.4g per 100g cooked
  • Vitamin C: 6% DV
  • Folate: 4% DV
  • Potassium: 3% DV
  • Phytonutrients: minimal

Frequent corn consumption promotes blood sugar spikes, weight gain, and inflammation. Corn is also commonly genetically modified.

3. Parsnips

Parsnips are root vegetables closely related to carrots with a very high glycemic index:

  • Calories: 75 per 100g
  • Glycemic load: 97
  • Fiber: 3.6g per 100g
  • Vitamin C: 24% DV
  • Folate: 12% DV
  • Potassium: 8% DV
  • Minimal phytonutrients

The combination of high calories and high glycemic load make parsnips unhealthy. Their plain starchy flavor provides little benefit to balance the sugariness.

4. Pumpkin

While pumpkin shines during fall festivities, it lacks nutritional substance:

  • Calories: 26 per 100g
  • Glycemic load: 15
  • Fiber: 0.5g per 100g
  • Vitamin A: 100% DV
  • Vitamin C: 19% DV
  • Potassium: 7% DV
  • Beta-carotene

Pumpkin is relatively high in calories yet low in fiber. The bright orange color signals high beta-carotene, but otherwise pumpkin falls short of other produce options. Use it sparingly to keep your blood sugar in check.

5. Cassava

Cassava, also known as yuca or manioc root, contains cyanide compounds that become toxic when eaten raw. Cooking neutralizes these harmful chemicals. However, cassava is still lacking in nutrition:

  • Calories: 160 per 100g
  • Glycemic load: 78
  • Fiber: 1.8g per 100g
  • Vitamin C: 20% DV
  • Thiamin: 11% DV
  • Potassium: 27% DV
  • No phytonutrients

The high starch and calorie levels combined with low fiber content earn cassava a spot on the worst vegetables list.

Healthiest Vegetable Alternatives

Rather than consuming large amounts of the vegetables above, make these healthy choices instead:

Vegetable Benefits
  • High in antioxidants like sulforaphane
  • Rich in vitamin C and vitamin K
  • Good fiber source
  • Low glycemic impact
  • Rich in iron, vitamin K, and folate
  • Contains antioxidants like lutein
  • High fiber content
  • Extremely low calories and carbs
  • High in antioxidants like glutathione
  • Excellent source of vitamins K and A
  • Low calorie and low glycemic
  • High in prebiotic fiber
Bell Peppers
  • Rich in antioxidants like vitamin C
  • Contains vision-protecting carotenoids
  • Low glycemic impact
  • High water content
Brussels Sprouts
  • High in cholesterol-lowering fiber
  • Contains sulforaphane and glucosinolates
  • Decent vitamin K and folate source
  • Low glycemic

Focus on getting a rainbow of non-starchy veggies to maximize nutrition and minimize blood sugar spikes.

Health Risks of Unhealthy Vegetables

While vegetables have an overall positive effect on health, consuming large amounts of the unhealthy kinds can pose the following risks:

Weight gain

The combination of calories, high sugar, and low fiber in unhealthy veggies promotes weight gain. Their high glycemic loads cause blood sugar crashes that spark hunger and overeating.


Frequent blood sugar spikes from high glycemic foods increase the risk of insulin resistance and type 2 diabetes over time.

Heart disease

The inflammation caused by sugary, starchy vegetables contributes to atherosclerosis. Plaque buildup increases chances of heart attack and stroke.


With minimal antioxidant and phytonutrient content, unhealthy vegetables lack the compounds that help prevent DNA damage from free radicals that can lead to cancer.

Fatty liver disease

Excess blood sugar is readily converted to fat in the liver. Over time, this hepatic fat buildup can progress to non-alcoholic fatty liver disease.

While occasional indulgences in these vegetables are unlikely to cause harm, making them a regular part of your diet can set you up for health consequences. Focus on quality over quantity when vegetable choices.

Tips for Reducing Unhealthy Vegetables

Here are some tips to limit your consumption of the most unhealthy vegetables:

  • Avoid ordering them as side dishes. Opt for healthier options like sautéed greens instead.
  • Limit potatoes to 1 small serving per week. Replace fries with roasted vegetables.
  • Reduce the sugar impact by always choosing non-starchy vegetables as 50% of your meal.
  • Sweeten savory dishes with onions, mushrooms, zucchini, and peppers instead of corn, pumpkin, or sweet potatoes.
  • When you do indulge, stick to a 1/2 cup or less to minimize glycemic impact.
  • Don’t keep unhealthy veggies stocked at home. Out of sight is out of mind.
  • Modify recipes to use riced cauliflower or spaghetti squash instead of heavy starches.
  • Get creative with healthy alternatives like turnips, jicama, radishes, and kohlrabi.
  • Fill up on fiber and water content with lower glycemic choices like Brussels sprouts and celery.

Carefully controlling portions and getting creative with vegetable choices can help you reduce the unhealthy options in your diet.


When consumed in excess, starchy and sugary vegetables high in calories but low in nutrients become detrimental for health. White potatoes, corn, parsnips, pumpkin, and cassava rank as the worst offenders. They provide minimal beneficial antioxidants and phytonutrients compared to their glycemic loads.

Focus your vegetable choices on fiber-rich, low glycemic options like leafy greens, cauliflower, broccoli, and asparagus. Limit high sugar veggies to occasional small sides. Make half your plate non-starchy produce and you’ll be on your way to a healthier vegetable-filled diet.


[1] FoodData Central, United States Department of Agriculture. https://fdc.nal.usda.gov/

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