Why is Protein So Important?

Amy Corcoran, MS, RDN

I don’t know about you, but I feel like there’s a lot of messaging around protein. I’m bombarded with protein powders, protein bars, protein-enriched snacks, and even protein-infused water!

Everywhere I turn, the world is telling me I need more protein. And let’s not forget the endless debates about animal versus plant-based proteins, complete versus incomplete proteins, and whether we should spread our protein intake throughout the day.

It’s easy to feel overwhelmed by all this nutrition noise. Let’s break it down and explore this essential macronutrient, how it works, and why it deserves a special spot on your plate.

What is Protein?

Biochemically, proteins consist of chains of amino acids, often described as building blocks. Think of amino acids as little Lego pieces that come together to form everything from muscles and bones to hormones and enzymes.

Nine of the 20 amino acids are essential, meaning you need them from your food because your body can’t make them. Here are the nine essential amino acids:

Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine

Protein Quality: Complete vs. Incomplete Proteins

You may have heard about complete and incomplete proteins. This classification refers to whether a protein contains all nine essential amino acids.

Complete Proteins: These proteins have all nine essential amino acids. They’re found in animal products like meat, fish, eggs, and dairy, as well as in some plant foods like quinoa and soy.
Incomplete Proteins: Most plant-based foods fall into this category, such as beans, lentils, and nuts.

A quick tip: If you follow a plant-based diet, you can “complement” your proteins by pairing foods low and high in certain amino acids. For example, combine beans (low in methionine, high in lysine) with rice (high in methionine, low in lysine) for a complete protein profile.

While not necessary, complementing proteins can ensure you meet your protein needs. Some classic combinations include:

Rice and beans
Peanut butter and whole wheat bread
Hummus and pita bread
Tofu and whole grains
Bean soup with crackers
Pasta with peas

Whether you follow a plant-based diet or not, it’s important to diversify your protein sources to meet your amino acid and overall nutrition needs.

How Much Protein Do I Need?

Now, let’s tackle the golden question: How much protein do I need? The good news is that most of us don’t need to worry about our protein intake—Americans get plenty!

The Recommended Dietary Allowance (RDA) for protein in adults is 0.8 grams per kilogram of body weight. For example, a 70 kg (about 154 lbs) adult should aim for 56 grams of protein daily. Here’s a handy calculator!

Important Note: RDAs are minimums designed to prevent deficiencies. In practice, many dietitians (including myself!) recommend closer to 1 to 1.2 grams/kg as baseline protein needs. Meet with our Philadelphia dietitians to determine your unique protein goal.

Special Considerations: When Protein Needs Change

Here are some scenarios where your protein needs might change:

Pregnant and Lactating Women: Protein needs rise to support a baby’s growth during pregnancy and breastfeeding.
Athletes: According to the International Society of Sports Nutrition, athletes may require between 1.4 to 2.0 g/kg, focusing on the amino acid leucine (more on this later!) and spacing protein intake every 3-4 hours.
Older Adults: As we age, protein becomes even more important for maintaining muscle mass—recommendations suggest 1.2 to 2 g/kg.
Chronic Kidney Disease (CKD): If you have CKD, it’s generally advised to limit protein intake if you’re not on dialysis, but to increase it if you are. Work with a renal dietitian to determine the right amount and types of protein for your needs.

FAQ Time!

Do high-protein diets harm kidney function?
For most healthy people, high-protein diets are safe. However, if you have kidney disease, it’s essential to consult a healthcare professional, as excessive protein can strain your kidneys. Be sure to drink more water as you increase protein to flush out wastes from protein breakdown.

What’s the scoop on leucine?
Leucine is an essential amino acid crucial for muscle protein synthesis. It’s found in animal products like chicken, fish, beef, eggs, and dairy. Plant-based sources include soybeans, lentils, and nuts, though they may have lower amounts.

For reference, an egg has 0.6 grams, a chicken breast has 2.5 grams, a ½ cup of cottage cheese has 1.27 grams, and a cup of lentils has 1.3 grams.

The minimum recommended intake of leucine is 42 mg/kg. For a person weighing 70 kg (154 lbs), this amounts to about 3 grams daily. Whey protein is popular among athletes due to its high leucine content.

Is protein spacing necessary?
Research suggests spreading protein intake throughout the day may optimize muscle growth, though individual research studies vary.

While some studies show evenly distributed protein supports increased muscle mass, others show total daily protein intake, irrespective of time, is generally more important for muscle growth.

My take? Space your protein! Most sports nutrition experts and consensus statements advocate for consistent protein spacing.

How to Boost Your Protein Intake

Ready to pump up the protein in your meals? Here are some ideas:

Protein-Packed Smoothies: Blend fruits with Greek yogurt, nut butter, or a scoop of protein powder.
Silken Tofu: This often-overlooked ingredient is great in smoothies and soups for a creamy texture and a protein boost.
Snack Smart: Keep protein-rich snacks like edamame, cottage cheese, or hard-boiled eggs on hand.
Try Legumes: Toss beans or lentils into salads, soups, or stews for an easy protein add-on.
Ingredient Swaps: Use Greek yogurt instead of sour cream or mix protein powder into your pancake batter.
Try Nut Butter: Spread almond or peanut butter on toast or fruit.

Meet with our Philadelphia nutritionists to create a protein-packed meal plan that suits your lifestyle.

Bottom Line

Protein seems to get the most attention of all the macronutrients—and for good reason! Beyond muscle health, protein is essential to make enzymes, hormones, antibodies, and even your hair and blood.

If you’re an athlete, pregnant, breastfeeding, or entering your older years, it’s an especially important time to focus on this mighty macronutrient.

So grab that protein-packed snack! Any questions or tips? Let’s hear them! And be sure to book now with our expert team of Philadephia dietitians.