Which Protein Source Is Best If You're Just Starting Your Fitness Journey? (2025)

If you recently started a new fitness routine, you may be interested in building muscle by adding more protein to your diet.

Instead of relying on protein powder, you should prioritize whole foods whenever possible, experts say.

“Ideally, most of your protein intake should come in the form of food,” said Alissa Rumsey, MS, RD, CDN, CSCS, founder of Alissa Rumsey Nutrition and Wellness.

How Much Protein Do You Need?

The Recommended Dietary Allowance of protein is 0.8 grams per kilogram (approximately 2.2 pounds) of body weight. But this recommended amount might be too low, according to Chris Kolba, PhD, PT, CSCS, a physical therapist specializing in sports medicine at The Ohio State University Wexner Medical Center.

“That’s just taking enough not to be deficient," Kolba said.

Instead, he recommends 1 to 1.2 grams of protein per kilogram of body weight, and older people may need a bit more since they may not absorb nutrients as efficiently. However, eating too much protein could cause gastric upset.

“If you’re not a high-level athlete, as long as you get the needed amount of protein within the 24 hours of the day, it doesn’t really matter,” Kolba said.

Which Protein Sources Should You Try?

If you’re looking to include more protein in your diet via whole foods, the following are good sources:

• Beans
• Eggs
• Lentils
• Meat
• Nuts
• Peas
• Poultry
  
• Seeds
• Soy products

If you can't get enough protein in your regular diet, you could try protein powder, but it's important to research the products as they are not regulated by the Food and Drug Administration (FDA).

“Their composition can vary widely and may not reflect what is on the label,” Rumsey said.

Whey protein is among the most popular types of protein powders. “It has all of the essential amino acids and is easily digested and absorbed,” Rumsey said. “Other types of protein supplements use soy protein, egg protein, milk protein, brown rice protein, pea protein, and hemp protein.”

Rumsey explained that isolate whey protein products have a larger percentage of protein—typically around 90%—compared to concentrate, which has about 70%-80%.

Isolate products also have less fat and carbohydrates than concentrate products because they are processed more, and they may be better for people who are lactose intolerant.

How Does Protein Help With Muscle Growth?

Increasing your protein intake won’t automatically result in larger muscles. “Muscle growth is a complex process that relies on hormones, physical activity, and adequate intake of protein and calories," Rumsey said.

But consistently eating enough may help you feel more energized and ready for more physical activity.

“When you incorporate strength training exercises, protein from food helps repair damage from exercising and builds up more muscle, making them stronger over time,” Rumsey said.

Since it can be difficult to see how your protein intake affects your body, Rumsey added, it may make more sense to track how much stronger you feel after you start eating adequate protein.