Let's take a look at the healthiest ways to include protein in your diet.
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Experts agree that protein is an essential part of a well-balanced diet. But there is still debate around exactly how much protein we need and the best sources — plant or animal.

Here, we look at the role protein plays in the body, how much protein we actually need, and the pros and cons of plant- and animal-based proteins.

What is protein and why is it important?

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Protein, carbohydrates, and fats are the essential macronutrients that your body needs to function properly. Each one plays an important role.

Protein is described by the National Library of Medicine as the building block of life. Every cell in the body contains protein — it is essential to the development and maintenance of all cells in the body. Additionally, research indicates that consuming foods that are high in protein can improve satiety , helping you feel full longer and eat less at your next meal.

Protein is made up of amino acids. Just as protein is the building block of life, amino acids are the building blocks of protein.

According to the Cleveland Clinic , amino acids combine to form a variety of proteins to carry out or support different functions in the body, including: digestion, immune support, hormone production, production of neurotransmitters, growth and repair of body tissue, building muscle, and the maintenance of healthy skin, hair, and nails.

Our bodies naturally produce a number of amino acids, called non-essential amino acids, but there are nine amino acids that can’t be produced by the body. These nine are called essential amino acids and must come from the foods we eat. Foods that contain all nine essential amino acids are called complete proteins.

How much protein do I need per day?

There is some debate over exactly how much protein we need, with most guidelines giving a daily range. Carolyn Williams , Ph.D., R.D. explains that the most accurate measurement would be to use the USDA Recommended Dietary Allowance (RDA) for protein since it is calculated using body weight.

To determine the RDA of protein for the average adult, multiply .8g times your body weight in kilograms. Using this formula, a 150-pound (68 kg) adult should consume approximately 54g of protein each day.

Athletes and older adults may need more protein. Athletes will need additional protein to meet the body’s increased metabolic demand. And older adults will need more protein, combined with strength training, to protect against sarcopenia, or age-related muscle loss.

For more specific and detailed recommendations, an online protein-intake calculator may be helpful to determine the lower and upper limits of your protein intake range based on age, gender, body-type, and activity level.

Pros and cons of animal protein

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Most complete proteins are animal proteins: eggs, fish, beef, poultry, and dairy are a few examples. Animal protein provides the highest quality complete protein available, especially for those looking to build muscle . Meat, poultry, fish, eggs, and dairy products provide each of the nine essential amino acids.

Consuming high quality, lean animal protein may be an important nutritional strategy to counteract the aging process; as age-related muscle loss, or sarcopenia, is linked to a decline in quality of life due to reduced mobility, fall-related injuries and disability.

Alternately, some animal proteins — specifically red meat and processed meats — have been linked to a higher instance of obesity, chronic diseases, and mortality. Processed meats are especially problematic, having been classified by the World Health Organization as a carcinogen.

Further, portion size should also be considered. Williams recommends eating between 4 to 8 oz of animal protein daily. A 4 oz serving is about the same size as an average woman’s palm or a deck of cards.

The takeaway for animal protein: focus on high quality, whole, lean proteins, such as poultry, eggs, yogurt, and fatty fish, and pay attention to portion size.

Pros and cons of plant protein

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There are numerous health benefits associated with eating a plant-based diet, including a reduced risk for developing obesity , cardiovascular disease , certain cancers , diabetes , and cognitive decline .

Plants should make up the bulk of every diet. Vegetables, fruit, legumes, nuts, and seeds provide excellent sources of antioxidants, vitamins, minerals, and fiber. They also provide protein.

Whole soy products, buckwheat, and quinoa are complete proteins, containing all nine essential amino acids. Other vegetables, fruit, legumes, nuts, and seeds, although not complete proteins, can be combined together and with other foods to create a complete protein.

While there are a number of newly developed plant-based foods that mimic traditional animal foods, it’s important to remember that these are still processed and ultra-processed foods. Just because an item is “plant-based” doesn’t mean that it is only made of plants. Read the ingredients label to check for additives, fillers, or other items that may be questionable.

The takeaway for plant-based protein: eat a wide variety of plant-based foods to ensure you are getting all of the essential amino acids. Focus on high quality, whole foods such as quinoa, leafy greens, lentils, whole soy, oats, and nuts and limit ultra-processed plant-based proteins.

Plant protein vs. animal protein and how to choose

Both plant-based and animal proteins can be included in a healthy, balanced diet. The key is to eat a wide variety of foods, focus on high quality, whole food sources of protein, limit or exclude processed meats, and increase the amount of vegetables in your diet.

Williams encourages us to think of our diets as “plant-forward.” The CDC estimates that only 1 in 10 Americans eat enough vegetables and fruit, a concern echoed by Williams. “Most of us are not eating enough vegetables and fruit. We don’t eat a good balance right now, and I definitely think we should shift to more plant- versus animal-based foods," she notes. "But this doesn’t mean we have to cut out all animal proteins. It isn’t all or nothing.”

Williams’ thoughts are in line with the Harvard School of Public Health 's philosophy of choosing protein based on the total nutrient package. T he idea is that, when choosing proteins, it is important to take into consideration the other nutrients that the food provides.

For example :

  • A 4 oz serving of broiled sirloin steak contains 33g protein (complete) and only 66mg sodium, but contains 4.6g of saturated fat.
  • A 4 oz serving of grilled sockeye salmon contains 30g protein (complete), 1g of Omega-3 fatty acids, and only 1.1g of saturated fat.
  • A 1 cup serving of cooked lentils contains 18g protein (incomplete), almost no fat or sodium, and a whopping 15g of fiber.

Using these comparisons can help us choose proteins based on the total nutrient package and our individual needs, instead of simply looking at the amount of protein per serving.