Does Your Protein Source Matter? — Protein Supplements vs. Food

It's no secret that protein is important. But does it matter where it comes from?

Products like protein powders, bars, shakes and even protein-infused waters often tout themselves as a convenient way to get more of the macronutrient. And indeed, they can be useful for some people, some of the time, according to experts. That said, they're not the same thing as protein from food.

There's a reason protein is sometimes referred to as the building block of life: It has a ‌lot‌ of vital jobs. "Protein is your body's superhero," says Marjorie Nolan Cohn, RD, LDN, clinical director of the nutritional therapy platform Berry Street. It's involved in:

• Helping your body repair cells and make new ones
  
• Supporting growth and development
  
• Building and maintaining muscle tissue
  
• Producing enzymes and hormones involved in digestion and immune response
  
• Helping you stay fuller longer, which can support weight management
  

The standard recommendation is 0.8 to 1 gram of protein per kilogram of body weight, per the Cleveland Clinic. This range is the recommended daily allowance (RDA) — essentially, the amount needed to meet basic requirements and prevent deficiency.

A more accurate daily benchmark for you depends on factors like your age, size and activity level. People who are larger typically need more protein than those who are smaller. Pregnant women, older adults, most active adults and those trying to gain muscle also may need more protein than the standard allowance.

You can figure out exactly how much protein you need using the USDA's calculator.

You can find protein in a wide range of foods, including animal- and plant-based sources. If you aren't able to meet your protein needs from food alone, supplements are another good option.

Plenty of foods are protein-packed. According to Harvard Health Publishing, some of the best sources include:

• ‌Lean meats‌ like chicken or turkey
  
• ‌Seafood‌ like salmon, tuna or shrimp
  
• ‌Eggs‌
  
• ‌Dairy‌ like milk, Greek yogurt, cottage cheese and cheese
  
• ‌Legumes‌ like lentils, black beans, chickpeas, split peas, white beans and kidney beans
  
• ‌Soy foods‌ like tofu, tempeh, edamame and soymilk
  
• ‌Nuts and seeds‌ like almonds and almond butter, peanuts and peanut butter, cashews, pistachios, sunflower seeds and pumpkin seeds
  

You'll find protein in plenty of other foods too, just in smaller amounts. Whole grains like brown rice, oatmeal and corn offer a few grams of protein per serving, for instance. There's even protein in veggies like spinach, Brussels sprouts and artichokes.

Animal-based proteins come in a "complete" package with all of the essential amino acids your body needs.

"Plant proteins are still able to give your body all of the essential amino acids it needs, but you have to make sure you're eating a variety of them," explains Asheville, North Carolina-based nutrition expert Katie Schwartz, RDN. "This is because some plant proteins contain certain amino acids and other plant proteins will contain other amino acids, making them complete when combined."

Protein can also be extracted or processed from animal or plant foods like cow's milk, eggs, soy, peas and even rice, per Harvard Health Publishing. The extracted protein (called protein isolate) can be added to nutritional supplements like:

• Protein powder
  
• Protein shakes
  
• Protein bars
  
• Protein cookies
  
• Protein waters
  

Some protein supplements (like unsweetened protein powder made without additives) deliver pure, simple protein. But often, packaged foods or drinks made with added protein have extra ingredients you may not need, like added sweeteners, supplemental nutrients, herbs or even fillers, Harvard Health Publishing notes. So it's important to read ingredient lists to know what you're getting.

You should aim to get the majority of your protein from whole foods when possible, recommends the Mayo Clinic. Whole foods come with additional nutrients your body needs, like carbohydrates, fiber, vitamins and minerals. That's not always the case with protein supplements. "Because these are isolates, they have removed all other nutrients other than the protein, making them digest quickly," Schwartz explains.

That said, protein supplements can be a good option if you're having trouble meeting your protein needs from food alone. "They can come in handy when you are sick, have a low appetite, are traveling or are busy. Athletes often need more protein too," says Schwartz.

Cohn often recommends using meal time to focus on whole food sources of protein, which can help you meet more of your nutritional needs. Think: a bowl of black bean soup or a salad topped with chicken or salmon. If you want something extra in between meals, that's when a supplement like a protein bar or a smoothie with a scoop of protein powder can come in handy, she says.

That's especially true if you're engaging in strength-training workouts to build muscle. In that case, "You can use protein from powder, supplements or drinks to add additional protein," says Haymarr Hann, MD, an internist with NYU Langone Health in New York City.

Whey protein powder is a particularly good choice here. "It's a complete protein that's high in the amino acid leucine, which supports muscle protein synthesis," Cohn says. (If you don't do dairy, rice or pea proteins are also good choices.)

Just keep in mind that more protein isn't always better. Your body can only use between 20 and 40 grams of protein at a time, evidence suggests, so you likely won't reap any additional benefits by adding a protein shake to an already protein-rich meal. Once you go above the 40-gram mark, the extra protein will likely just be stored as fat, the Cleveland Clinic notes.

Excess protein is turned into glycogen through the process of gluconeogensis. If the glycogen isn't needed by the body, the protein is stored as fat.

It pays to do your research when you're buying a protein powder. "I vet products to make sure they provide the minimum amount of protein per serving ideal for you and contain minimal artificial ingredients. It's also important to choose a protein powder that has been third-party tested to ensure quality and safety," Cohn says.

Here's what she and Schwartz recommend you look for:

• ‌High in protein:‌ A powder should have at least 20 percent of your daily protein requirements.
  
• ‌Complete protein:‌ Options like whey are complete all by themselves. If you're going with a plant-based protein powder, look for a combo like rice and pea to make sure you're getting all of your essential amino acids from one scoop.
  
• ‌Third-party verified:‌ When you choose a powder that's been vetted by a known certifier (like NSF or USP), you can rest easy knowing that the product contains what it says on the label — and nothing extra.
  
• ‌Meets your nutritional needs:‌ Check the powder's calorie count and added sugars. Some options might have more than you'd expect.
  

It's best to get the majority of your protein from whole, unprocessed foods whenever you can. But a high-quality protein supplement can be a good addition to your diet if you're strength training or need additional nutrients when you're sick, have a low appetite, are traveling or are simply too busy to prepare nutrient-rich foods. Just try not to overdo it.