Complete vs. Incomplete Protein Sources: What's the Difference?By Leslie Barrie Reviewed by Monica Ropar, Nutritionist Science-Backed
The health benefits of eating protein go way beyond just building muscle.1 This nutrient powerhouse also helps keep your bones strong and skin healthy.2 Another protein plus? When included in a balanced diet, it could support weight loss by helping to boost metabolism (it takes more energy to digest proteins vs. carbohydrates or fats).3 Protein-packed foods can also help you feel satisfied, so you’re not reaching for a bag of chips later!
Still, if you’re looking for foods with protein, you may have experienced some major moments of confusion. For example, when wandering down the grocery aisle, have you noticed that some packaged goods — like beef jerky — tout that they’re a “complete protein”? Or, have you read articles that call certain foods, like beans, “incomplete proteins”? If you’re thinking — what gives? — you’re not alone. Discover the difference between a complete and incomplete protein, so you can make the best nutritional choices for you.
The big differentiator between complete and incomplete protein
The big difference between complete vs. incomplete proteins is the number of essential amino acids the food contains. While that might sound super complicated, we promise, it’s not! Complete proteins contain the nine essential amino acids that you can only get through food.1 Fun fact: Your body can make other amino acids on its own!
On the other hand, an incomplete protein lacks some of these nine essential amino acids. That doesn’t necessarily make incomplete protein sources “bad proteins,” it just means you’ll have to get those amino acids you’re missing elsewhere (more on that later!).
Photo by Natalia Y on Unsplash
Now at this point, you might be trying to think back to biology class — asking, what exactly is an amino acid anyway? Amino acids are compounds that come together to form a protein, and are considered the “building blocks of life.”4 You need these amino acids to help your body function — so they are kind of a big deal.
What foods contain incomplete vs. complete protein sources?
If you’re looking for healthy foods that are complete proteins, you’re in luck! Here is a list of foods that are considered complete proteins. They are also excellent choices to include in a healthy diet:1
- Beef (opt for lean cuts)
- Whole forms of soy (think: tofu and edamame)
So, if you’re trying to make a smart meal choice, why not opt for grilled salmon, a chicken breast, a lean cut of beef, or tofu (paired with ample non-starchy veggies, of course!)?
And for snacks, healthy options include edamame, a hard-boiled egg, or some milk with a high fiber, whole-grain cereal.
As for incomplete proteins, they include:1
- Whole grains
- Legumes (like beans and lentils)
- Nuts and seeds
Most of these foods are healthy staples, too. Many of them are even excellent healthy non-perishable foods. So, for example, you can enjoy a cup of bean-based soup with whole-grain bread for dinner, or rice and beans with vegetables.
And for snacks, you can opt for nut butter on apple slices, or veggies dipped in hummus. What’s more, when choosing incomplete protein foods, it’s worth thinking about what protein-rich foods compliment them, so you can get a complete nine essential amino acids with your meal.
The scoop on complementary proteins
It may seem like a bummer that such healthy fare like veggies, fruits and nuts don’t have all the amino acids you need. But the good news? You can combine these incomplete protein sources with other incomplete proteins so that you get all the nine essential amino acids. Some examples of complementary proteins include:5,6
- Rice and beans
- Peanut butter on whole-wheat bread
- Tacos filled with beans or lentils
- Noodle stir fry with peanut sauce
- Hummus with pita bread
Photo by Nicholas Barbaros on Unsplash
Another option: You can combine complete proteins with incomplete proteins for even more of a protein punch (think yogurt with nuts).
If you start to feel your stress levels rising just thinking about protein combinations, don’t fret. You don’t have to make sure every meal has all your essential amino acids — it’s just about eating multiple protein sources throughout your day, which will add up to the complete protein totals you need.1 So enjoy those protein-packed meals, stress-free!
We hope this has helped you understand the difference between complete vs. incomplete protein and how to get the most out of your meals.
Are you interested in a weight loss program that takes the guesswork out of calorie counting and figuring out how much protein you need at every meal? Jenny Craig can help. View our new plans starting as low as $12.99 a day and get started on the path to better health today!
Leslie Barrie has a health writing and editing background, and holds her master's degree from Columbia University Graduate Journalism School. Over the past 10 years, she has worked at various magazines in New York City, such as Woman's Day, Health, Seventeen, and more. When she's not writing about health, she likes living it — she enjoys running, hiking, swimming, and yoga (even though she's not the best at it, it helps her to relax!).
Favorite healthy snack: a piece of dark chocolate with a handful of almonds
Monica Ropar, Nutritionist
Monica has over 15 years of experience with Jenny Craig, as an expert nutrition and program resource. She develops content, training, tools and strategies for the program to support clients throughout their weight loss journey, and offers inspiration, weight loss tips, lifestyle strategies and motivation. Monica holds a Bachelor of Science degree with a double major in Dietetics and Exercise, Fitness & Health from Purdue University and continues to stay current on weight management research, consumer trends and healthcare developments.
Favorite healthy snack: raw veggie sticks with homemade hummus
This article is based on scientific research and/or other scientific articles and was written by an experienced health and lifestyle contributor and reviewed by certified professionals.
Our goal at Jenny Craig is to provide the most up-to-date and objective information on health-related topics, so our readers can make informed decisions based on factual content. All articles undergo an extensive review process, and depending on the topic, are reviewed by a Registered Dietitian Nutritionist (RDN) or Nutritionist, to ensure accuracy.
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Edited by Elisa - Jenny Craig