We often think about how our food impacts our health. But have you considered how your cooking method might impact your food's health value? Exposing certain foods to heat for too long can reduce the vitamin content and the availability of antioxidants1,2. Additionally, the cooking oil you use may add significant calories to your food3. Here are some tips on healthier cooking methods.
Nutrients Damaged by Heat
It's important to know which nutrients are vulnerable to high heat during cooking. Vitamin K and most minerals are not typically affected by temperature. However, heat can damage vitamins E and C, along with most B complex vitamins ,with the exception of niacin and riboflavin.
When you cook in water, it will cause damage to potassium, the majority of the B complex vitamins, and vitamin C. When you cook in fat, it can reduce the vitamins A, D, and E in those foods.
Cooking with Liquid
Boiling: You can boil food in broth, stock or water when it hits 212°F. Many different types of foods are boiled, including shellfish, eggs, chicken, pasta, and vegetables. Boiling can affect the nutritional content of food, especially if you boil for an extended amount of time. You will lose a lot of vitamin C and B complex from vegetables. Some of the nutrients will be lost in the water.
Blanching: This is another option which uses boiling water, but you only put the food into it for a short amount of time. It is often done as a first step in preserving foods, because it stops the enzymes and helps vegetables maintain a bright color. You will lose a minimum amount of nutrients because the cooking time is short.
Simmering: This is similar to boiling, but you do it at a lower temperature and it is not as harsh. The liquid will be brought to a boil in many cases and then the heat turned down to a simmer. You will still lose nutrients in a similar way to boiling.
Poaching: This is a method similar to simmering, but you don't bring the water to a boil before you add the food. Poaching is also done at a lower temperature, so you may lose fewer nutrients, but it is similar to boiling or simmering.
Stewing (brazing): When you cook your food in a liquid at a lower temperature, including fish, meat and vegetables, it is known as stewing. You will likely lose a lot of vitamin C, but the other nutrients will be retained, as long as you serve the liquid with the food being cooked.
Steaming: This is a method that also uses liquid, but you don't put the food into the water. You use the heat from the steam to cook the food. Steaming is perhaps the healthiest choice as far as nutrient retention is concerned. It isn't difficult to do, but you have to purchase a vegetable steamer or a steaming basket to do it properly.
Pressure Cooking: This is a specialty type of cooking that uses a pressure cooker at a high temperature. Since the cooking time is shorter than boiling, you will likely lose fewer nutrients.
All in all, you are going to lose nutrients when you cook with liquid. But since these methods don't require additional fats, so you aren't adding additional calories to the food. If you want to use the healthiest method, steaming is probably the choice to make.
Cooking with Dry Heat
Roasting: You typically roast food in an oven, and you may or may not add fat. The temperatures can range from 285-400°F. It is a common way to cook meat, fish, vegetables, and eggs. Because of the exposure to high heat, you will likely damage vitamin C and the majority of B complex vitamins. In some cases, you may also destroy some of the vitamins A and E if extra fat is used.
Sautéing: This dry heat cooking method requires a little fat to keep it from sticking to the pan. It is frequently used for vegetables or marinating meats. Since very little fat is used, you don't lose many nutrients.
Grilling/Broiling: You can cook food over flame, charcoal or heating elements and it isn't always necessary to add fats. You will typically lose heat-sensitive vitamins, but you will also drain some fat naturally as it cooks.
Baking: This is the option mostly used for making bread, cookies, and other dough-based products. People also bake potatoes and casseroles. You will damage some of the vitamin C and B-complex, but the most important things to consider are the ingredients. Typically, you bake things that are not as healthy for you, so keep that in mind.
Microwaves: Most homes have a microwave oven and they use it primarily to reheat food. You don't lose many nutrients because the cooking time is short, but if you don't cook the food thoroughly, it could lead to illness.
Cooking with Fat
Deep-frying: Although this is a popular way to cook certain types of food, it is also one of the types you may want to avoid. You are essentially plunging your food into boiling fat, so it will absorb some of the fat. As a result, the calories will go up.
Pan-frying: This is similar to deep frying, but you don't use as much oil. If you make the wrong food choices, it could absorb a lot of the fat and the calories go up considerably.
Stir-frying: Since you are using hot temperatures for a short amount of time, the loss of nutrients will be minimal. You will also likely use a very small amount of oil, so it is a healthier cooking method.
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.
To make sure you are getting enough of your daily vitamins and nutrients take the NATURELO Whole Food Multivitamins made with fruits and vegetables.
1. Cooking losses of thiamin in food and its nutritional significance, 1990;36 Suppl 1:S17-24
2. Nestle Professional. "Cooking Methods.", June 6, 2006
3. Effect Of Heating On Vitamin C Content Of Some Selected Vegetables, NOVEMBER 2013