Does Cooking Food Affect Protein Content?

Cooking some high protein foods might remove fats while leaving proteins intact.
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Beef, chicken, fish and eggs are all rich in protein, but the way you cook them affects their composition. Whether you grill, steam or pan-fry these foods, find out the effect of cooking on protein levels and how to boost their nutritional value.


Studies assessing the effect of cooking food on protein levels had surprising results. Beef and chicken, as well as fish and beans, all lose protein during cooking; eggs, on the other hand, have more digestible protein as they are cooked.

Effect of Cooking on Protein

Meats, such as beef and chicken, are a great addition to your diet as they contain protein and other key nutrients. For example, one beef patty with a quarter pound of ground beef has 20 grams of protein. A skinless chicken breast boasts 52 grams of protein. To get the most nutrition from your food, it's important to understand the effects of cooking on its protein content.


A November 2016 study in Comprehensive Reviews in Food Science and Food Safety found that something interesting happens to meat when cooked at high temperatures — it loses protein. Meats cooked at 212 degrees Fahrenheit lost 40 percent of their myosin heavy chain proteins, while cooking at 284 Fahrenheit resulted in an 80 percent loss.

This doesn't mean you should eat your meat undercooked, though. To avoid food poisoning, the USDA recommends beef to be cooked at a minimum temperature of 145 degrees Fahrenheit, while ground beef should be cooked until it reaches 160 degrees. Chicken should reach a temperature of 165 degrees to ensure that it's free of bacteria and other pathogens that may cause foodborne illnesses.


The negative effects of cooking on nutrients in meat can be minimized by choosing the right cooking method. Grilling temperatures easily reach 375 degrees Fahrenheit, resulting in meat that is cooked quickly over high heat, which may cause protein loss. Broiling, where temperatures get as high as 500 degrees, has similar effects.

Your best bet? A slow cooker set at low heat for a longer time keeps the meat in the optimal range for safety without going above the 212-degree mark. Poaching and stewing are other optimal cooking methods for meat. If you plan on baking meat in the oven, check the temperature to make sure it reaches the safe level without getting too hot.


If you choose to cook your steak on the stove, keep a close eye on the temperature to prevent burning. Also, consider the marinades or cooking oils used. Antioxidant-rich olive oil is a better choice than butter or heavy glazes. They will both add to the overall calorie count, so keep the oil light.

Read more: The Health Benefits of Eating Red Meat

How Cooking Alters Fish Protein

What is the effect of cooking on nutrients in fish? As it turns out, fish reacts similarly to beef and chicken, so the protein is lost during high-heat cooking.


A May 2017 study in RSC Advances has shown that roasting and frying fish fillets resulted in more protein oxidation than other cooking methods. Researchers recommend boiling or steaming fish at a maximum temperature of 212 degrees Fahrenheit, which is similar to what the studies on meat showed.

The study explains that heat causes a series of reactions that result in damage to the cellular structure of meat and fish. This affects their protein content and antioxidant properties.

One option to get the full benefits of fish is to eat it raw in sushi. To ensure the safety of the food, FDA states that fish must have been kept frozen at –4 degrees Fahrenheit for seven days or for 15 hours at a temperature of –31 degrees. Always buy sushi from reputable establishments to ensure they are following food safety guidelines.

Read more: The Best and Worst Sushi To Order

Cooking Beans and Eggs

The effect of cooking on protein in beans shouldn't be overlooked either. A February 2017 study in the International Journal of Food Science acknowledges that beans must be cooked before consumption, even though they do lose protein. Despite this fact, they're still a good source of proteins, fiber and minerals.

To maximize their health benefits, stick to black beans, lentils, garbanzo beans and kidney beans instead of refried beans, which are often loaded with saturated fats. When you buy canned beans, opt for low-sodium brands with no added sugar. Check the labels to get a clear picture of the ingredients used.

Eggs, on the other hand, are not that sensitive to the detrimental effects of cooking. An March 2018 study in the Journal of Food Science showed that cooking eggs increases protein digestibility. One hard-boiled egg has 6 grams of protein and 77 calories, so it packs a lot of nutrition without adding inches to your waistline.