Protein Requirements by Age: A Complete Guide

In this article, we explore protein requirements by age. You’ll learn how much protein is needed at different stages of life and how these requirements vary based on your fitness goals.

Protein Requirements by Age: Age Is Not Just a Number

Protein is an essential nutrient required for numerous functions, including building and repairing tissues and skeletal muscle, synthesizing enzymes and hormones, and supporting your immune system.

protein requirements by age functions of protein

As we age, our protein requirements change with us. 

We need higher protein intakes during periods of rapid growth and development, such as infancy and adolescence, as well as during aging, when the body’s ability to use protein becomes less efficient.

If you’re looking to build muscle, strength, and an athletic physique, your protein needs go up, and a teenager does not necessarily require the exact amounts as a senior lifter over 65.

Official Protein Requirements by Age

The following is the recommended dietary allowance (RDA) of protein for a given age, as determined by the Food and Nutrition Board of the National Academy of Sciences, Engineering, and Medicine.1

It’s the minimum amount of protein your need for health and to prevent deficiencies.

Older Infants

  • 7–12 months: 1.2 g/kg/day or 11 g/d of protein


  • 1–3 years: 1.05 g/kg/d or 13 g/d of protein
  • 4–8 years: 0.95 g/kg/d or 19 g/d of protein
  • 9–13 years: 0.95 g/kg/d of 34 g/d of protein


  • 14–18 years: 0.85 g/kg/d of protein 


  • 19 and above: 0.85 g/kg/d of protein

Recommended Protein Requirements by Age for Optimal Health and Muscle Development

Below are the protein requirements by age for youth athletes and adults to promote exercise performance, recovery, and muscle development, as suggested in scientific reviews.

Adolescents Aged 10–18 years

  • 1.2–1.8 g/kg/day to maximize performance and support growth and development

Adults Aged 19–59

  • ≥1.6 g/kg/day to maximize muscle growth
  • 2 g/kg/day to maintain lean mass during weight loss
  • 2.3–3.1 g/kg/day to maintain muscle mass during weight loss for already lean athletes and bodybuilders

Older Adults Aged 60 and Above

  • 1.2 g/kg/day to optimize physical function and muscle health
  • ≥2 g/kg/day to maximize muscle growth
  • ≥2 g/kg/day to maintain lean mass during weight loss

Protein Requirements by Age Calculator

Do you want to know how much protein you need for general health, muscle gain, and fat loss?

Use our spiffy protein calculator! This easy-to-use tool considers your age and fitness goals to determine how much protein you need each day.

It is based on the protein requirements by age according to current recommendations referenced in this article, and you can choose between protein per kilogram or per pound of body weight.

Check the buttons to calculate protein requirements!

Protein Requirements By Age
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Protein requirements for age 7–12 months

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Protein requirements for age 1–3 years

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Protein requirements for age 4–8 years

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Protein requirements for age 9–13 years

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Protein requirements for age 14–18 years

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Protein requirements for age 19–64 years

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Protein requirements for age 65+ years

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What Do the Dietary Reference Intakes for Protein Mean?

Dietary reference intakes (DRIs) are a set of nutrient reference values estimating how much you need of a nutrient for health and to prevent deficiencies and chronic diseases.

The DRIs are established by the Food and Nutrition Board of the National Academy of Medicine in the United States and are based on scientific research on nutrient requirements.

DRIs include several different types of nutrient reference values, including the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), the Tolerable Upper Intake Level (UL), and the Estimated Average Requirement (EAR), and are established for various age groups.

Recommended Dietary Allowance (RDA) for Protein

The RDA is the minimum amount of protein needed to prevent deficiencies and avoid muscle loss. Your individual protein needs vary based on factors such as how physically active you are, your age, and your health status.

If you want to build lean mass and muscle strength, eating the RDA of protein will only get you so far. The optimal protein intake for elite athletes and bodybuilders trying to pack on muscle can be more than twice as high as the RDA.

Estimated Average Requirement (EAR) for Protein

The EAR for protein is the amount estimated to meet the needs of 50% of healthy individuals. You want to exceed the EAR by a substantial margin. Chances are the EAR will provide less protein than you need for good health, let alone enough to build muscle and recover from exercise.

The EAR meets the needs of 50% of the population, RDA meets the needs of 97.5% of the population.

Adequate Intake (AI) for Protein

The AI of a nutrient is a value based on observed or experimentally determined approximations and is used when an RDA cannot be determined. The AI for protein is only used for young infants up to six months.

Upper Limit (UL) for Protein

UL stands for “Tolerable Upper Intake Level,” which is the highest level of daily nutrient intake likely to have no adverse effects on almost all individuals in the general population.

There is no UL for protein!

No tolerable upper intake level for protein consumption has been established, and no adverse consequences (including cancer, kidney disease, kidney stones, and osteoporosis) of high protein intakes have been identified.2

Our Recommendations for Protein Intake by Age

In this article, you’ll find much higher protein intake recommendations than the RDA.

It’s important to remember that the RDA of protein is not necessarily the optimal amount for good health and certainly not for building muscle mass.

Instead, we base our protein recommendations on scientific research looking specifically at healthy people of all ages and the following health and fitness goals:

  • Health
  • Performance
  • Muscle health and growth
  • Weight management and fat loss (for adults)

Let’s get into it, starting with the youngest!

Protein Requirements for Older Infants

The protein needs of an older infant between 7 and 12 months are greater than those of older children and adults. 

All tissues in the young body grow faster than later in life, increasing the protein requirements to supply all the necessary building blocks.

The RDA of protein for older infants is 1.2 g/kg/day or an average of 11 grams g/d.

That amount provides enough to cover the protein needs for health and development, plus the additional demand for protein for normally growing young children.

Protein Requirements for Children

For boys and girls between the ages of 1 to 13, the RDA ranges from 0.95 to 1.05 grams of protein per kilogram of body weight per day. Young children need more protein to support growth.

  • 1–3 years: 1.05 g/kg/d or 13 g/d of protein
  • 4–8 years: 0.95 g/kg/d or 19 g/d of protein
  • 9–13 years: 0.95 g/kg/d of 34 g/d of protein

While young children need more protein per unit of body weight, too much protein is not a good idea.

A higher protein intake in early childhood (≤ 18 months) is likely a risk factor for weight gain, overweight, and obesity later in childhood.3

High-protein diets, especially if they are high in animal sources of protein, may lead to increased production of insulin and insulin-like growth factor 1 (IGF-1), which are both known to promote growth. Unwanted growth, in this case, which might mean additional fat cells.

That’s not a suggestion to exclude animal protein sources from a child’s diet. Animal proteins provide all the essential amino acids and other nutrients necessary for growth and development.

The point is that too much protein in early childhood could lead to being overweight and a high BMI later on. There is no need to overdo the protein in the hope that it will improve health and help the child develop muscle mass. That happens naturally from a balanced diet, and in the case of young children, too much of a good thing might not be good at all.

Read more:

>> Strength Training For Children and Adolescents

Protein Requirements for Adolescents Aged 14 to 18

The growth spurt during adolescence is second only to the one during the first year of life. Those rapid changes require nutritional support, including protein, for optimal growth potential.

Generally, girls increase their lean mass until 15 years of age, while boys increase in lean mass until age 18, with the most rapid increase occurring between 12 and 15.

  • RDA for boys, 14–18 years: 0.85 g/kg/d or an average of 52 g protein.
  • RDA for girls, 14–18 years: 0.85 g/kg/d or an average of 46 g protein.

The current recommended dietary allowance is enough for health and avoiding deficiencies but not enough for youth athletes looking to maximize performance and build muscle.

Athletes, regardless of age, generally burn more calories than sedentary persons. Although absolute protein needs are higher in teenage athletes, the recommendations are usually the same in terms of percentage of energy intake, 12% to 15%, although some recent research points out some benefits from a slightly higher intake.

Younger people who practice sports and youth athletes need between 1.2 and 1.8 g/kg of body weight per day.4 5 That is enough protein to support healthy growth and development during periods of frequent and high-intensity exercise.

Adolescents and young adults should focus on getting their dietary protein from whole foods rather than protein supplements. There is no scientific support for claims that protein powders are superior to naturally protein-rich foods. Also, whole foods provide other nutrients vital for the young athlete, not just protein.

There is nothing harmful about using a protein supplement for extra protein during adolescence, though. If you want to use a whey protein shake for additional high-quality protein, go for it, but emphasize whole foods instead of protein supplements.

After training, ≥20 grams of high-quality protein shortly afterward promote muscle repair, growth, and recovery. 

Protein Requirements for Adults Aged 19 to 65

US and European authorities recommend a daily protein intake of ~0.8 grams per kilogram of body weight and day for healthy adults. The recommended dietary allowance is enough for almost everyone to live a healthy life and avoid protein deficiency.

However, it’s not enough for optimal performance and recovery if your physical activity levels are high or you exercise regularly. 

The current recommended intakes of dietary protein for strength and endurance athletes are 1.6 to 1.7 g/kg and 1.2 to 1.4 g/kg per day, respectively.6

You likely need at least those amounts if you lift weights and want to optimize your muscle mass gains. Strength training increases muscle protein synthesis and muscle breakdown, and protein is the most important nutrient for repairing muscle fibers and building new muscle tissue.

Different authorities mention different numbers, but they all recommend significantly higher amounts than the RDA.

  • The American College of Sports Medicine recommends consuming 1.2–1.7 grams of protein per kg of body weight per day if you want to increase your muscle mass.
  • Accorting to the International Society of Sports Nutrition, strength athletes and resistance-trained individuals who want to build muscle should eat at least 1.4 g/kg/day. A protein consumption of up to 2 g/kg/day might be ideal for some.
  • The most extensive systematic review to date, published in the British Journal of Sports Medicine, suggests that 1.6–2.2 grams g/kg/d of protein might be necessary to optimize gains in muscle mass.

Sources:7 8 9

The above recommendations are all for when you eat at least as many daily calories as you burn.

Your protein requirements increase during weight loss or when you’re trying to diet away unwanted body fat.

Along with lifting weights, eating more protein is the best way to prevent the loss of muscle mass during a calorie deficit.

On the other hand, a low protein intake and no weight training during weight loss can lead to a 50/50 loss of muscle/fat. Not ideal for improving your body composition 

Evidence suggests at least 2g/kg/d of protein when restricting your calorie intake to maintain fat-free mass.8

The leaner you get, the more protein you need to retain muscle. Athletes and bodybuilders who are already lean but looking to get shredded should aim for 2.3–3.1 g/kg of fat-free mass to avoid losing muscle.8

how to cut for bodybuilding

The last recommendation is based on lean body mass instead of total body weight. That’s because your fat tissue is not metabolically demanding. If you calculate the protein content of your low-calorie fat-loss diet based on your total body weight, chances are you won’t eat much besides protein.

In addition to helping preserve your hard-earned muscle mass during weight loss, a high protein diet offers several other benefits:

  • Protein is the most satiating macronutrient, more so than fat and carbs.
  • Protein has the highest thermic effect of the macronutrients, meaning your body burns more calories digesting and metabolizing it.

In other words, increasing your protein intake can help you lose body fat by increasing fullness and reducing your overall calorie intake.

Read more:

>> Protein for Strength Training: The Ultimate Guide

>> How Much Protein Do You Need per Day to Gain Muscle?

Protein Requirements for Older Adults Aged 65+

As we age, our bodies become less efficient at using protein, and we require more protein to maintain muscle mass and prevent age-related muscle loss. And if you want to gain muscle after 65, you must consider not only how much protein you eat but also when you eat it and its quality.

Older people need more protein than younger adults for several reasons.

  • Your muscle mass naturally decreases as you get older.
  • You build less muscle each time you eat a protein-rich meal than when you were young.

The decline in muscle mass primarily starts after age 50 at a rate of about 1–2% per year but may begin as early as the age of 30 years. After 60, the rate of decline accelerates rapidly.10

The good news is that you only lose significant muscle mass with age if you let it happen.

You have two primary ways to combat the age-related loss of muscle:

  • Lift weights. Nothing elevates muscle protein synthesis and stimulates muscle growth like resistance training.
  • Eat more protein. A high protein intake works together with strength training to not only retain muscle mass but increase it.
older lifters protein requirements by age

The recommended dietary allowance (RDA) is unchanged from 0.8 g/kg/day.

Unfortunately, it does not account for the loss of muscle mass that typically occurs with aging. 

According to recent research, the current Recommended Dietary Intakes for protein are likely inadequate for optimal health and the maintenance of physical function and optimal health in older adults.11

After 60–65, you likely need between 1 and 1.3 g/kg/day of protein, especially if you’re physically active.

No official recommendations exist for strength-training older adults seeking to maximize muscle gains. However, because the general protein requirements for muscle health are higher in older individuals, a higher protein intake would also benefit your training results.

A daily protein intake of 1.4 to 2.0 g/kg/day is still a minimum recommendation, while higher amounts might be necessary to maximize your potential for muscle growth.

The Best Protein Sources for Different Age Groups

At different points in life, some protein sources offer various benefits over others. Here are the best protein sources as you age.

Infants (0-6 Months)

Breast milk or formula provides all the necessary protein for infants.

Babies (7-12 Months)

Breast milk or formula is still the primary source of protein, but you can introduce solid foods.

protein requirements by age toddler

You should only introduce one new food should at a time.

It is usually a good idea to introduce meats, a good source of iron and zinc, as one of the first complementary foods to breast milk/formula.

Children (1-3 Years)

After the first year, a child’s diet more and more resembles that of an adult, although strong likes or dislikes of particular foods often become apparent at this point.

By two years of age, the toddler’s diet should consist of the same foods as the rest of the family. A varied and healthy diet selected according to general dietary guidelines provides all known required nutrients.

Good protein sources include meat, fish, poultry, eggs, dairy products, beans, and lentils. 

Children and Adolescents (4-18 Years)

At this point, good food is good food. There are no special requirements you have to think of when it comes to protein choices.

The primary consideration is to support continued growth and development with enough calories from a balanced diet and mainly whole foods. 

The energy needs among children and adolescents aged 4-18 vary considerably. Physically active kids and youth athletes burn much more calories than sedentary children. Even among similar groups of children, energy expenditure can vary by up to 20%.

As long as young people cover their calorie needs, they usually get enough protein, provided their diet is based on nutritious food choices. A mix of plant-based protein sources and animal protein ensures adequate protein quality and a variety of other key nutrients.

There is no need for additional protein supplements, not even for youth athletes.

Adults (19-65 Years)

Getting enough protein to meet general recommendations is not a problem for most adults. Research shows that men and women over 20 generally eat more protein than the RDA.12

According to the Dietary Guidelines for Americans, you should focus on nutrient-dense foods that provide vitamins, minerals, and other health-promoting components.13 As for protein, that means lean meats, poultry, and eggs; seafood; beans, peas, and lentils; and nuts, seeds, and soy products.

How much protein you eat isn’t everything for maintaining and building muscle mass. Quality is also essential.

Animal sources of protein, such as meat, poultry, and dairy products, are considered high-quality protein sources because they contain all the essential amino acids that the body needs.

The essential amino acids are the ones you need to provide through your diet to build muscle.

Plant-based foods like legumes, nuts, and seeds can also be high-quality protein sources when combined properly. Most protein sources from plants do not provide enough of all the essential amino acids you need.

  • Legumes, lentils, peas, and vegetables: combine with grains, nuts, and seeds.
  • Grains, nuts, and seeds: combine with legumes.
protein requirements animal protein and plant protein

A balanced and varied diet that includes a variety of protein sources helps ensure an adequate protein intake that also benefits your health.

Overall, animal sources are the ones with the highest protein quality. Here is a list of protein sources loosely ranked for muscle-building potential.

  • Milk and dairy products (milk, yogurt, cheese, cottage cheese, greek yogurt, quark, casein- and whey protein powder)
  • Eggs and egg whites
  • Red meat (beef, pork, lamb, game, ostrich)
  • White meat (chicken, turkey)
  • Fish and seafood
  • Soy-based foods (tofu, tempeh, edamame, soy protein powder)
  • Quinoa
  • Beans, lentils
  • Nuts, almonds, seeds
  • Whole grains


Older Adults (65+ Years)

Many older adults don’t get enough protein. A recent study showed that almost half of the most senior US adults did not meet protein recommendations.15 The ones eating the least protein also had the most functional limitations in their everyday life.

The best protein sources for healthy older adults looking to build muscle are the same as for younger adults, although protein quality becomes even more crucial.

As you age, your sensitivity to a protein-rich meal goes down. You need more protein to get the same boost in muscle protein synthesis (MPS) you got when you were younger. The amino acid leucine plays an important role in triggering MPS, and the protein sources providing the most leucine come from the animal kingdom.

  • Lean meats, poultry, and fish are good sources of high-quality protein and important nutrients like vitamin B12 and omega-3 fatty acids.
  • Eggs are a fantastic source of amino acids and are often considered the gold standard for protein quality.
  • Dairy products like milk, yogurt, and cheese are excellent sources of protein, calcium, and other essential nutrients. Whey, a protein from cow’s milk, is especially rich in leucine.
  • Legumes, including beans, lentils, and chickpeas, are good plant-based protein sources. Most are not considered complete proteins on their own, but as part of a varied diet, they help boost your protein intake if you eat little or no animal proteins.
  • Nuts and seeds are relatively good sources of protein and provide plenty of healthy fats and other vital nutrients at the same time. Examples include almonds, walnuts, chia seeds, and flaxseeds. Remember that nuts and seeds are exceptionally calorie-dense, and excess calories lead to potentially unwanted fat gain. Nuts should not be your primary protein source but are a good complement and a healthy snack.
  • Soy products like tofu, tempeh, and edamame are good sources of high-quality protein and can help bone health. Soy protein is one of the few plant-based proteins that provide enough essential amino acids needed for muscle growth and repair.

In addition to ensuring an adequate daily protein intake, older adults should distribute their protein intake reasonably evenly throughout the day, approximately 3–4 hours apart, to promote muscle protein synthesis throughout the day.

A protein supplement can be a good idea if you struggle to get enough protein from your regular diet. Whey protein is the ideal protein supplement for older adults.

Older lifters also need more protein per serving to boost muscle protein synthesis maximally. Unlike young people, who only require 20 grams per serving, seniors require ~40 grams of high-quality protein to maximize MPS.8

Consider consuming a protein-rich (~40 grams) snack or shake after working out to support muscle growth and recovery. Protein timing around a training session becomes more critical with age.

Read more:

>> How Much Protein To Build Muscle After 60

>> The Best Protein Powder for Men and Women Over 50

>> Building Muscle After 50: The Essential Guide

Final Words

That concludes this guide to protein requirements by age!

Our protein needs change with age as our bodies undergo physiological changes.

  • Infants and young children require a high amount of protein per kilogram of body weight to support their rapid growth and development.
  • Adolescents require more protein than adults because they are still growing and developing. 
  • Healthy adults might have the lowest protein requirement per kilogram of body weight, but this amount is significantly higher for physically active individuals, athletes, lifters, and bodybuilders.
  • Older adults’ bodies are less efficient at using protein and require more protein to maintain muscle mass.

Regardless of how young or old you might be, a balanced diet with adequate amounts of protein from plant and animal-based sources ensures that you stay healthy and that your body and muscles have the building material they need to develop, grow, and thrive.


  1. Food and Nutrition Board of the National Academies of Sciences Engineering, and Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids.
  2. Gropper SS, Smith JL, Carr TP. Advanced Nutrition and Human Metabolism. Eighth ed. Boston MA: Cengage Learning; 2022.
  3. Food Nutr Res. 2022; 66: 10.29219/fnr.v66.8242. Protein intake in children and growth and risk of overweight or obesity: A systematic review and meta-analysis.
  4. J Sports Med. 2015; 2015: 734649. Nutritional Considerations for Performance in Young Athletes.
  5. J Sports Sci. 2007;25 Suppl 1:S73-82. Nutrition for the young athlete.
  6. Nutr Clin Care. 2002 Jul-Aug;5(4):191-6. What are the dietary protein requirements of physically active individuals? New evidence on the effects of exercise on protein utilization during post-exercise recovery.
  7. ACSM Information on Protein Intake for Optimal Muscle Maintenance.
  8. Journal of the International Society of Sports Nutrition, Volume 14, Article number: 20 (2017). International Society of Sports Nutrition Position Stand: protein and exercise.
  9. Br J Sports Med. 2018 Mar;52(6):376-384. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.
  10. Curr Opin Clin Nutr Metab Care. 2004 Jul; 7(4): 405–410. Muscle tissue changes with aging.
  11. Nutrients. 2015 Aug; 7(8): 6874–6899. Protein Requirements and Recommendations for Older People: A Review.
  12. U.S. Department of Agriculture, Agricultural Research Service 2008. Nutrient Intakes from Food: Mean Amounts and Percentages of Calories from Protein, Carbohydrate, Fat, and Alcohol.
  13. Dietary Guidelines for Americans 2020–2025, Executive Summary
  14. Sports Medicine volume 49, pages59–68(2019). Food-First Approach to Enhance the Regulation of Post-exercise Skeletal Muscle Protein Synthesis and Remodeling.
  15. The Journal of Nutrition, Health & Aging Volume 23, Pages 338–347 (2019. Low Dietary Protein Intakes and Associated Dietary Patterns and Functional Limitations in an Aging Population: A NHANES Analysis.
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Andreas Abelsson

Andreas is a certified nutrition coach and bodybuilding specialist with over three decades of training experience. He has followed and reported on the research fields of exercise, nutrition, and health for almost as long and is a specialist in metabolic health and nutrition coaching for athletes. Read more about Andreas and StrengthLog by clicking here.