Are Roasted Vegetables Healthy – The Ultimate Guide

Roasting is a common way of cooking vegetables. Whether you want to lightly roast vegetables for soup or cook them fully for a salad, side dish, pita, or main dish, roasting adds flavor to your vegetables.

Is Roasting a Healthy Way to Cook Vegetables?

Roasted vegetables can be a healthy option as they are a good source of vitamins and minerals. Roasting vegetables helps to bring out their natural sweetness and can make them more palatable.

assorted vegetables on wood chopping board

However, the nutritional value of roasted vegetables can vary depending on the type of vegetables and how they are prepared. It is important to also consider the amount of oil and salt used during the roasting process, as excess amounts can add extra calories and sodium to the dish. Also, consume roasted vegetables in the recommended portion sizes.

Does Roasting Veggies Ruin Nutrients?

Roasting veggies can cause a loss of water-soluble vitamins such as vitamins C and B. On the flip side, roasting encourages the activation of beneficial compounds such as carotenoids and phenols.

Carotenoids are a type of plant pigment that give fruits and vegetables their yellow, orange, and red colors and are beneficial for eye health. Phenols are compounds found in fruits and vegetables and are associated with antioxidant activity, anti-inflammatory effects, and improved blood sugar control.

roasted mix veggies on white plate

However, over-cooking the vegetables or cooking them at extremely high temperatures can cause a significant loss of nutrients. To minimize nutrient loss, keeping the cooking time and temperature within the recommended range for the specific vegetables is best.

Also, avoid adding too much oil or seasonings that can cause the vegetables to char or burn.

How to Roast Vegetables to Retain Their Nutrients

Here are some tips for roasting vegetables in a way that helps to retain their nutrients:

Use minimal oil

Roasting vegetables with a minimal amount of oil will help to keep the calorie and fat content low. Toss the vegetables in just enough oil to coat them lightly.

Avoid overcooking

Overcooking vegetables can cause them to lose some nutrients, especially water-soluble vitamins like vitamin C and B. To retain their nutrients, vegetables should be roasted until they are tender but still crisp.

Use a medium to high temperature

Roasting vegetables at an extremely high temperature can cause them to lose some of their nutrients. Roasting at around 375-400F for a longer period can help retain more of the vegetables’ nutrients.

Don’t peel the vegetables

The skin of many vegetables contains a lot of nutrients. Therefore, peeling it can cause the vegetables to lose some of their nutritional value. Instead, wash the skin thoroughly to remove dirt and cut off any blemishes or damaged parts.

Don’t crowd the baking sheet

Crowding the baking sheet can cause the vegetables to steam instead of roast, resulting in soggy rather than crispy vegetables. Spread the vegetables out in a single layer on the baking sheet, leaving some spaces between individual pieces.

roasted vegetables on baking tray

Roast vegetables with a high-water content separately

Vegetables with high water content, such as tomatoes, mushrooms, and zucchini, release a lot of liquid while roasting. This can cause other vegetables to steam instead of roast.

Avoid covering or wrapping vegetables in aluminum foil when roasting

Roasting vegetables in aluminum foil can cause them to lose some of their nutrients. Instead, use a baking sheet lined with parchment paper for easy cleanup.

Roast in a cast-iron skillet

Cast-iron skillets conduct heat evenly and retain heat well, which can help to retain the vegetables to cook fast and evenly.

Add an acidic ingredient to the vegetables

For example, add lemon juice, vinegar or tomato sauce to the vegetables before roasting. The acidity slows down the oxidation process, preserving the natural color and flavor of the vegetables.

Cut the vegetables evenly

Slice and dice your veggies to the same size for optimal roasting.

cutting veggies for roasting

Flip the veggies halfway through the cooking time

Flip it well! Keep those veggies evenly cooked and delicious by flipping them halfway through the roasting process.

Best Equipment for Roasting Vegetables to Retain Nutrients

Several types of equipment can be used to roast vegetables, and the best one for you will depend on your preferences and what you have available. Here are a few options:

  • Oven. Roasting vegetables in the oven is a popular and convenient method. You can use a baking sheet or dish. Make sure to use a baking sheet with a lip to prevent juices from spilling over.
  • Air fryer. An air fryer uses hot air to cook food and can be a great way to roast vegetables. Air fryers cook food quickly and can produce a crispy texture.
  • Skillet. Roasting vegetables in a skillet on the stovetop can be a quick and easy method. A cast iron skillet is a good option as it can withstand high heat and is also oven safe.

How Long Should You Roast Vegetables For?

The roasting time for vegetables will vary depending on the type and size of the vegetable, as well as your desired level of doneness.

Generally, softer vegetables take a shorter time to cook than harder vegetables. For example, green beans, broccoli, and cauliflower cook in 10 to 20 minutes, while hard vegetables such as potatoes, squash, and pumpkin can take 30 minutes or more.

As a general guideline, vegetables cut into small pieces should be roasted at 425°-450°F (220°-230°C) for about 15-20 minutes or until they are tender and lightly browned.

On the other hand, vegetables cut into larger pieces should be roasted at 425°-450°F (220°-230°C) for about 25-35 minutes or until they are tender and lightly browned.

roasted brussels sprouts on blue plate

It’s recommended to check the vegetables every 10 minutes or so, so they don’t get overcooked or burned. This is because some vegetables may cook faster or slower than others.

Also, how crowded your baking sheet is can affect the cooking time. The more crowded it is, the longer it takes to cook.

Here are some general guidelines for common vegetables:

  • Root vegetables (such as potatoes, carrots, and parsnips) should be roasted at 425°-450° Fahrenheit for 25-35 minutes.
  • Cruciferous vegetables—broccoli, cauliflower, and brussels sprouts—should be roasted at 425° Fahrenheit for 15-20 minutes.
  • Bell pepper, eggplant, and zucchini should be roasted at 425° Fahrenheit for 15-20 minutes.
  • Tomatoes, onions, and garlic should be roasted at 425° Fahrenheit for 15-20 minutes.
  • Leafy greens—such as kale and spinach—should be lightly coated in oil and roasted at 425° Fahrenheit for 5-8 minutes.

Simple Roasted Vegetables Recipe


  • 1 lb of vegetables (such as broccoli, bell pepper, and zucchini)
  • 2 tbsp olive oil
  • Salt and black pepper, to taste
  • Optional seasonings (such as garlic powder, Italian seasoning, or red pepper flakes)


  1. Preheat your oven to 425°F (220°C)
  2. Cut the vegetables into bite-sized pieces and place them in a mixing bowl
  3. Add the olive oil, salt, black pepper, and any optional seasonings to the bowl, and toss until the vegetables are evenly coated
  4. Spread the vegetables out on a baking sheet in a single layer
  5. Roast the vegetables in the preheated oven for 20-25 minutes or until they are tender and slightly browned
  6. Enjoy your roasted veggies as a side dish, or add them to a salad, sandwich, or grain bowl for a delicious and healthy meal


Both steaming and roasting vegetables can be healthy cooking methods as long as they are done in a way to preserve nutrients in the vegetables.

Of the two, steaming is considered the most effective way to retain the nutrients in the vegetables, as it does not require the use of oils or fats, and the vegetables are not exposed to high temperatures for long periods.

Roasting can also be a healthy cooking method as long as the vegetables are not cooked at too high a temperature or for too long, as this can cause them to lose some of their nutrients. Additionally, using healthy oils such as olive oil can provide additional health benefits when roasting vegetables.

Grilling and roasting vegetables can be healthy cooking methods. Grilling vegetables is a good way to retain flavor and texture and can add a smoky or charred taste to the vegetables.

However, the high heat from grilling can also cause some loss of water-soluble vitamins such as vitamins C and B. On the other side, like roasting, it also encourages the formation of beneficial compounds such as carotenoids and phenols.

The main difference between grilling and roasting is that vegetables are cooked at much higher temperatures, which can lead to the loss of more nutrients.


In general, roasting vegetables is a good way to prepare raw vegetables for healthy eating. However, avoid overcooking or cooking at extremely high temperatures to prevent nutrient loss. Also, choose your seasonings carefully to avoid adding too many calories. You can roast vegetables using an oven, air fryer or skillet, depending on what you have at hand or your preference.

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