What Is the Healthiest Cooking Method?

stir fry on the stove
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The cooking methods you choose affect the nutritional value of the foods you serve. For example, long exposure to heat reduces the overall vitamin content of your foods but will increase the availability of some antioxidant phytochemicals. In addition, cooking methods that require added fats or oils tend to add a lot of calories to a meal. So, which cooking method is the healthiest? That's not an easy question to answer, but here's a look at several different cooking methods and how they affect the nutrient content of your food.

Nutrients Damaged by Heat

First, it's good to know which nutrients are more vulnerable to cooking. For the most part, vitamin K and most minerals aren't really affected by temperatures or contact with water, heat, and air, except for potassium that can be lost to cooking liquids.

Heat damages vitamins E and C plus most of the B-complex vitamins, except for riboflavin and niacin. Cooking in water will cause vitamin C, most of the B-complex vitamins, and potassium to be damaged or leached into the liquid. Cooking in fat can reduce vitamin A, D, and E.

Not all cooking methods have the same effects on all foods and there're more to choosing a healthy cooking method. But in general, cooking methods that take the least amount of time do the least amount of nutritional damage. And since we take pleasure in eating, it's important to consider what cooking does to the flavor and texture of food.

Cooking Methods Using Liquids

Boiling involves cooking in water, broth, stock or other liquid at 212 degrees Fahrenheit. Vegetables, pasta, chicken, shellfish, and eggs in the shell are often boiled. The effect of boiling on nutritional content varies depending on how long the foods are boiled. Veggies lose a lot of their vitamin C and B-complex vitamins, but the availability of some carotenoids may increase, at least in some vegetables. Some of the nutrients are leached into the water.

Blanching is when you plunge food into boiling water for a short time and is often the first step to preserving foods because it stops enzymes and helps veggies keep their bright colors. The nutrient loss is minimal because the cooking time is quite short.

Simmering is like boiling but at a lower temperature (180 to 200 degrees Fahrenheit) and is more gentle. Typically, the liquid is brought to a boil then the heart is turned down and allowed to simmer. The nutrient loss is similar to boiling.

Poaching is similar to simmering, but the water is not brought up to a boil before the food is added. Water temperature for poaching is also lower than boiling and simmering, but the nutrient loss is usually about the same. Eggs, fish, and some fruits are often poached.

Stewing (or braising) involves cooking in liquid, usually at a lower temperature, and typically is used for meats, fish, and veggies. The long cooking time and heat exposure mean a lot of vitamin C will be lost, but any other nutrients leached into the cooking liquid will be retained as long as you serve it as a sauce, stew or soup.

Steaming also uses liquid but the food isn't plunged into the water. Instead, the heat from the steam does the cooking. Of all the cooking methods that involve liquid, steaming appears to be best for nutrient retention. Steaming food isn't too difficult, but you need to purchase a freestanding vegetable steamer or a steaming basket.

Pressure cooking involves the use of a special pressure cooker that allows for higher temperatures. The cooking time is much shorter than boiling, and fewer nutrients are lost in the process.

Bottom line: While the amount of nutrient loss is high in most cooking methods using liquids, they don't require the use of any extra fats so none of these methods will increase the calorie content of foods. Steaming is often the best of these methods because it also keeps most of the nutrients intact.

Cooking Methods Using Dry Heat

Roasting involves cooking your food in the oven with or without added fat, at a temperature between 285 and 400 degrees Fahrenheit. Roasting is often used to cook meats, fish, vegetables, and eggs. Roasting damages vitamin C and most B-complex vitamins due to the heat, and vitamins A and E may also be destroyed if extra fat is added. In addition, over-roasting can result in the formation of acrylamide, a compound which may be linked to cancer, but more research is needed.

Sauteing is a dry-heat method that usually requires a small amount of fat to keep food from sticking to the pan. It's often used for vegetables and some types of tender or marinated meats. Very little fat is added and the cooking time is shorter, so fewer nutrients are lost.

Grilling or broiling involves cooking over charcoals, flames, or heating elements with or without added fats. Heat sensitive vitamins are lost but some fat is also lost as it drains out. A wide variety of foods can be cooked on a grill including fish, meat vegetables, potatoes, and some fruit.

Baking is mostly used for bread, cookies, pastries and other foods made with dough, such as pizza. But you can also bake casseroles and potatoes. The heat damages vitamin C and many of the B-complex vitamins but what really makes or breaks baking as a healthy cooking method is the ingredients in your product. One plus, though, is that baking makes grains a little easier to digest, but it can also cause the formation of acrylamides in grains and potatoes.

Microwave ovens are often used to reheat leftovers but it's also a good way to cook some vegetables. The short cooking time means there's only a minimal loss of nutrients, which is good. The biggest difficulty with using a microwave is heating foods all the way through to a temperature hot enough to kill bacteria, so it's not a good way to cook meats and poultry.

Cooking Methods Using Fat

Deep-frying is when you fully submerge your food in oil that's heating to between 285 to 375 degrees Fahrenheit. You'll typically need a standalone deep-fryer or a large pot for deep-frying. Since it's a fairly quick way to cook foods, it doesn't cause as much nutrient loss as boiling and other water methods, but since the foods absorb some of the oil, the calorie count and fat content of the food can go way up.

Pan-frying is similar to deep-frying in that the food is cooked in hot oil, but less oil is used in the frying pan. Depending on the foods you're pan-frying, the calorie count and fat absorption can be high.

Stir-frying relies on hot temperatures and a small amount of oil. Due to the short cooking time, not much of the nutritional content is lost. Since only a small amount of oil is used, stir-fried dishes can be both nutritious and low in calories.

Nutrient Loss, the Quick Version

According to Nestle Professional, some of these cooking methods can be ranked by vitamin loss, from worst to best:

  • Boiling (35 to 60 percent loss)
  • Steaming (10 to 25 percent loss)
  • Microwave cooking (5 to 25 percent loss)
  • Pressure cooking (5 to 10 percent loss)
  • Roasting (10 to 47 percent loss)
  • Stewing, grilling, and baking (10 to 12 percent loss)
  • Frying (7 to 10 percent loss)

How to Make All Your Cooking Methods Healthier

No matter which cooking method you choose, there are a few steps you can take to preserve nutrients and improve the health benefits:

  • Whether you boil, poach, stir-fry, or saute, cook your veggies until they are just tender, not until they are mushy.
  • Serve cooked foods immediately because keeping food warm causes an even greater loss of vitamin C.
  • Since you know cooked foods lose some of their nutrients, add some raw fruits and veggies (as a snack or a salad) every day to make sure you get enough vitamin C.
  • If you need to add any fats to the dish you're cooking, it's best to choose a healthier oil such as olive oil or canola oil, and drain off any extra fat before serving.
  • Use cooking liquids to make soups and stocks. If you can't use it right away, go ahead and freeze the nutrient-rich liquid for later use.
  • When grilling, make sure the meat is not too moist so it browns better. And make sure the grill is plenty hot before adding your foods.
  • Baking at a temperature below 356 degrees Fahrenheit and frying at a temperature no higher than 347 degrees Fahrenheit will help reduce acrylamide formation.
  • Use spray oils to lightly coat pans to reduce the amount of oil used.

    A Word From Verywell

    The cooking methods you choose are important for the texture and flavor of your foods but also affect the nutritional value. Choose methods that allow for less nutrient loss but don't require the addition of large amounts fat. No cooking method is perfect, so be sure to get an ample amount of fresh fruits and veggies every day as part of a healthy balanced diet.

    Sources:

    Adriana D.T. Fabbri, Guy A. Crosby, "A Review of the Impact of Preparation and  Cooking on the Nutritional Quality of Vegetables and Legumes." Int J Gastron Food Sci, Volume 3, 2016.

    Gao-feng Yuan, Bo Sun, Jing Yuan, and Qiao-mei Wang."Effects of Different Cooking Methods on Health-promoting Compounds of Broccoli."  J Zhejiang Univ Sci B. 2009 Aug; 10(8): 580–588.

    Nestle Professional. "Cooking Methods."