Complete vs. Incomplete Proteins: What Should Parents Know?

As parents, you always want to make sure that your child is getting optimal nutrition. One of the integral components of making sure of a balanced diet is including complete protein which provides all the essential amino acids for your child’s growth and development. But how do you differentiate between complete and incomplete protein? This blog will give you all the information you need on it.

Table of Contents

• What is protein made of?
• What are complete and incomplete proteins?
• Complete protein vs incomplete protein: key differences
• Best sources of complete protein for kids
• Ways to combine incomplete proteins for a balanced diet
• Why a balanced protein intake matters for growing children?
• Conclusion
• Source

What is protein made of?¹

Different types of amino acids act as building blocks to make various proteins. Amino acids can be classified into two categories that is essential and non-essential amino acids. Out of 20, there are 9 essential amino acids which cannot be made by the body and are therefore essential to get through the diet. They are necessary for all round growth.

What are complete and incomplete proteins?

The difference in nutritional value of complete vs incomplete proteins is determined by whether or not it contains all the nine essential amino acids.

1. Complete Proteins:

These protein sources contain all nine essential amino acids in adequate proportions required by the human body.

2. Incomplete Proteins:

These protein sources lack one or more essential amino acids.

Complete Protein vs. Incomplete Protein: Key Differences

Complete Protein	Incomplete Protein
Contains all 9 essential amino acids	Lacks one or more essential amino acids
Can be a standalone source of protein	Needs to be combined with other complementary protein sources to make a complete protein
Has high bioavailability2	Has a lower biological value meaning the body does not absorb all the protein present in the food.
Found mostly in animal food sources	Found in plant-based foods

Best Sources of Complete Proteins for Kids

Following are the foods which are not only complete proteins but also the best energy foods for kids.

1. Eggs³

Egg is an excellent example of complete protein. It also comes with other important nutrients like vitamin A, vitamin D, selenium, folate and choline which promotes child’s cognitive function.

2. Dairy⁴

Milk and milk products are also complete proteins. Cow’s milk especially is also a good source of Branched Chain Amino Acids (BCAA) which promotes muscle growth and prevents muscle breakdown. Milk products like curd and paneer can also be included in some fun recipes for kids⁵.

3. Meat and fish⁶

All kinds of meats and fish have very high amounts of complete proteins. They can be easily included in the form of curries, grilled or tandoor to meet the child’s daily protein requirement.

4. Quinoa⁷

Quinoa is also known as “pseudo cereal” and is a complete protein. You can simply replace rice with quinoa or make some delicious dosas and tikkis or kebabs with it.

5. Soyabean⁸

Soyabean and animal proteins have a very similar amino acid profile with all the essential amino acids present and is therefore considered a complete protein¹. It also has the highest biological value among all the plant-based proteins.

6. Pistachios⁹

Believe it or “nut”, pistachios are a complete protein providing all nine essential amino acids in addition to phytonutrients, healthy fats and fiber. It can be a super tasty and convenient healthy snacking option.

Ways to Combine Incomplete Proteins for a Balanced Diet¹⁰

As all the incomplete proteins lack different essential amino acids, you can always combine them with other complementary incomplete proteins to mimic the amino acid composition of complete proteins. This technique is especially useful for vegetarians and vegans¹¹.

The following is a breakdown of protein complementation:

FOOD	LIMITING AMINO ACID	COMPLEMENT
Beans/Legumes	Methionine	Grains, dairy
Grains	Lysine, Threonine	Legumes, dairy
Nuts	Methionine	Grains, dairy

The recipes of common Indian foods can be modified to add to the protein quality and quantity. This can be done without affecting the palatability or making major changes. Cereal pulse combination and addition of dairy products like curd, paneer, buttermilk or cheese and nuts further add to the protein content of the meal and helps to meet the recommendations.

Some of the few examples of protein complementation are:

• Dal with Rice/ Chapati
• Puran Poli
• Rajma Chawal
• Dal baati
• Idli/ Dosa with sambhar
• Thalipeeth
• Dal Dhokli
• Khichdi
• Soya Pulao
• Pitla bhakri
• Handvo
• Dal paratha
• Curd Rice
• Paneer Pulao

Why a Balanced Protein Intake Matters for Growing Children?

Protein is an essential macronutrient that is required for optimal growth and development of the child and yet a majority of the children do not meet their daily protein requirements. This is because Indian diets mainly consist of carbohydrate rich foods and lacks protein.

The body is dependent on complete protein for various different functions like¹²:

1. Forming digestive enzymes
2. Promoting immune function
3. Promoting cognitive function by making neurotransmitters
4. Moving essential molecules around the body
5. Supporting muscle contraction and movement
6. Facilitating general growth and development of the child.

Without the essential amino acids present in the diet, regular bodily functions may get compromised and lead to issues like stunted growth, poor immunity, reduced academic achievements, lethargy, and fatigue. Hence, an active effort needs to be made to include diverse sources of protein like pulses, eggs, dairy, meat, fish, quinoa, soyabean and nuts in every meal of the child’s diet to make sure they receive an adequate protein intake.

Conclusion

Understanding complete and incomplete proteins equips you to make an informed choice for your child. If you are finding it difficult to include enough complete protein in your child’s diet, then you can rely on Complan as it has 63% more protein than leading malt based drink to support your child’s growth and development.

Source:

¹Lopez MJ, Mohiuddin SS. Biochemistry, Essential Amino Acids. [Updated 2024 Apr 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557845/

²Peter Furst, Basics in clinical nutrition: Proteins and amino acids 2008, e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism

³Puglisi, M. J., & Fernandez, M. L. (2022). The Health Benefits of Egg Protein. Nutrients, 14(14), 2904. https://doi.org/10.3390/nu14142904

⁴Davoodi, S. H., Shahbazi, R., Esmaeili, S., Sohrabvandi, S., Mortazavian, A., Jazayeri, S., & Taslimi, A. (2016). Health-Related Aspects of Milk Proteins. Iranian journal of pharmaceutical research : IJPR, 15(3), 573–591.

⁵Moberg, M., Apró, W., Ekblom, B., van Hall, G., Holmberg, H. C., & Blomstrand, E. (2016). Activation of mTORC1 by leucine is potentiated by branched-chain amino acids and even more so by essential amino acids following resistance exercise. American journal of physiology. Cell physiology, 310(11), C874–C884. https://doi.org/10.1152/ajpcell.00374.2015

⁶Ryu, B., Shin, K.-H., & Kim, S.-K. (2021). Muscle Protein Hydrolysates and Amino Acid Composition in Fish. Marine Drugs, 19(7), 377. https://doi.org/10.3390/md19070377

⁷Craine, E. B., & Murphy, K. M. (2020). Seed Composition and Amino Acid Profiles for Quinoa Grown in Washington State. Frontiers in nutrition, 7, 126. https://doi.org/10.3389/fnut.2020.00126

⁸Kudełka, W., Kowalska, M., & Popis, M. (2021). Quality of Soybean Products in Terms of Essential Amino Acids Composition. Molecules (Basel, Switzerland), 26(16), 5071. https://doi.org/10.3390/molecules26165071

⁹Derbyshire, E., Higgs, J., Feeney, M. J., & Carughi, A. (2023). Believe It or ‘Nut‘: Why It Is Time to Set the Record Straight on Nut Protein Quality: Pistachio (Pistacia vera L.) Focus. Nutrients, 15(9), 2158. https://doi.org/10.3390/nu15092158

¹⁰Dimina, L., Rémond, D., Huneau, J. F., & Mariotti, F. (2022). Combining Plant Proteins to Achieve Amino Acid Profiles Adapted to Various Nutritional Objectives-An Exploratory Analysis Using Linear Programming. Frontiers in nutrition, 8, 809685. https://doi.org/10.3389/fnut.2021.809685

¹¹Mariotti, F., & Gardner, C. D. (2019). Dietary Protein and Amino Acids in Vegetarian Diets—A Review. Nutrients, 11(11), 2661. https://doi.org/10.3390/nu11112661

¹²Espinosa-Salas S, Gonzalez-Arias M. Nutrition: Macronutrient Intake, Imbalances, and Interventions. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK594226/