How many proteins do we really need for optimal health?

December 16, 2025 •

4 min read

The average American consumes around 16% of their daily calories from protein, but what is the ideal amount? Answering the question, "How many proteins do we really need?" depends on a variety of personal factors, including age, weight, and activity level. This guide will help you understand your body's unique requirements.

Quick Summary

This guide outlines the daily protein requirements for different individuals, emphasizing how factors like age, activity level, and goals influence needs. It details high-quality protein sources and explains the benefits of adequate intake for overall health and body composition.

Key Points

RDA is a Minimum, Not an Optimum: The standard recommendation of 0.8 g/kg is the bare minimum to avoid deficiency, not the optimal amount for everyone.
Needs Vary by Lifestyle: Active individuals, older adults, and people losing weight require higher protein intake, sometimes up to 2.2 g/kg, to support their goals.
Protein Aids Weight Management: Higher protein diets boost metabolism, reduce appetite, and help preserve muscle mass during a calorie deficit.
Prioritize Protein Quality: Animal sources provide complete protein, while a variety of plant-based proteins must be consumed to get all essential amino acids.
Listen to Your Body: Symptoms like muscle loss, fatigue, brittle hair, and slow healing can indicate insufficient protein intake.
High-Protein Diets Can Have Risks: Excessive protein, especially from unhealthy sources, can strain kidneys and may lead to other health issues in some individuals.

Understanding the Basics: What is the Protein RDA?

Proteins are fundamental building blocks of the human body, vital for muscle, bone, skin, and enzymes. The Recommended Dietary Allowance (RDA) for protein is a minimum threshold, set at 0.8 grams per kilogram (0.36 grams per pound) of body weight for adults. This is the amount needed to prevent deficiency, but it's not necessarily optimal for everyone, especially those with specific fitness goals or who are aging. Many individuals, particularly older adults or athletes, can benefit from a higher intake.

How Your Needs Change with Life and Goals

Protein requirements are not static throughout life. They shift based on your physiological state and lifestyle. For example, older adults have higher needs to counteract muscle loss, and athletes need more to support muscle repair and growth. Here's a breakdown of how various factors impact your protein intake.

For the Sedentary Adult

For those with a sedentary lifestyle, the RDA of 0.8 g/kg is sufficient to meet basic nutritional needs and prevent deficiency. For a 150-pound (68 kg) individual, this amounts to about 55 grams per day.

For Athletes and Active Individuals

Physical activity increases protein turnover, meaning more protein is needed for muscle repair and adaptation. Depending on intensity and goals, active people and athletes may need between 1.2 and 2.0 grams of protein per kilogram of body weight daily. This higher range supports muscle repair, growth, and overall performance.

For Weight Loss

When aiming for weight loss, a higher protein intake can be beneficial. Protein helps increase satiety, reduce appetite, and preserve lean muscle mass during a calorie deficit. A daily intake of 1.6 to 2.2 grams per kilogram of body weight is often recommended for those seeking to lose weight while retaining muscle.

For Older Adults

Age-related muscle loss, known as sarcopenia, can be mitigated by a higher protein intake. Recommendations for older adults often increase to 1.0 to 1.6 grams per kilogram of body weight to help preserve muscle mass and function.

For Vegetarians and Vegans

Plant-based proteins are generally less digestible than animal proteins and may lack optimal levels of certain essential amino acids. Vegetarians and vegans may need a slightly higher total protein intake (around 10–20% more than omnivores) to compensate, along with strategic food combining to ensure a complete amino acid profile.

High-Quality Protein Sources: Animal vs. Plant

Both animal and plant-based foods can provide excellent sources of protein. Animal products are considered 'complete' proteins as they contain all nine essential amino acids. Plant proteins can be complemented by combining different sources throughout the day.

Animal Sources:
- Lean meats: Chicken breast, lean beef, turkey.
- Fish and seafood: Salmon, cod, shrimp.
- Eggs: An excellent source of high-quality protein.
- Dairy products: Greek yogurt, cottage cheese, milk.
Plant Sources:
- Legumes: Lentils, chickpeas, black beans.
- Soy products: Tofu, tempeh, edamame.
- Quinoa: A complete plant protein source.
- Nuts and seeds: Almonds, pumpkin seeds, peanut butter.

Protein Comparison Table: Animal vs. Plant


Feature	Animal Protein	Plant Protein
Completeness	Contains all essential amino acids (complete).	Often limited in one or more essential amino acids (incomplete), but can be combined to form a complete profile.
Digestibility	Generally highly digestible and bioavailable.	Typically less digestible due to fiber content, requiring a higher intake to compensate.
Nutrient Profile	High in iron, zinc, and B12.	Often rich in fiber, vitamins, and minerals.
Saturated Fat	May be high, depending on the source (e.g., red meat).	Generally low or absent.
Cardiovascular Impact	Higher intake of red and processed meats linked to increased heart disease risk.	Associated with a lower risk of heart disease.

Common Symptoms of Protein Deficiency

Signs that you might not be getting enough protein include:

Muscle loss and weakness
Weak and brittle hair and nails
Swelling, known as edema, in the legs or feet
Feeling fatigued or weak
Increased appetite and cravings
Frequent illness and slow wound healing
Mood changes and mental fog

If you notice these symptoms, it is best to speak with a healthcare professional or registered dietitian.

Conclusion

So, how many proteins do we really need? The answer is nuanced and depends on your individual circumstances. The 0.8 g/kg RDA is a minimum, but active individuals, older adults, and those aiming for weight loss often require more—up to 1.6 to 2.2 g/kg. For most, a simple shift toward including a protein source in every meal can make a significant difference. Focusing on a variety of quality sources, from lean meats to plant-based options like legumes and soy, is the key to optimizing your intake for better overall health, weight management, and muscle maintenance.

For more detailed information on maximizing your dietary protein, consider consulting a healthcare professional or exploring resources like the Harvard T.H. Chan School of Public Health's guide to protein.

Frequently Asked Questions

A simple starting point for the average adult is to multiply your body weight in pounds by 0.36 to find the minimum daily grams of protein needed. For example, a 150-pound person needs at least 54 grams. More active individuals should aim for a higher multiplier.

Yes, it is possible to get enough protein from a plant-based diet. To ensure you receive all essential amino acids, you should eat a wide variety of plant protein sources, such as beans, lentils, tofu, quinoa, and nuts.

No, more protein is not always better. For muscle growth, the optimal range is typically 1.6–2.2 g/kg daily, combined with resistance training. Consuming more than this offers diminishing returns and may contribute to excess calorie intake.

While generally safe for healthy people, excessive protein intake can put a strain on the kidneys, increase the risk of dehydration, and potentially lead to nutrient imbalances if it replaces other food groups. Those with pre-existing kidney conditions should be particularly cautious.

Some studies suggest that having protein within an hour or two of a workout can aid muscle repair, but consistent daily intake is more important. The total daily amount and distributing it evenly across meals matter more than specific timing for most people.

A protein deficiency can lead to significant health issues, including muscle wasting, weakened immunity, fatigue, brittle hair and nails, and edema (swelling). These symptoms often worsen over time if not addressed.

You can boost your protein intake with simple swaps like adding Greek yogurt to breakfast, snacking on nuts or a handful of edamame, and incorporating beans or lentils into lunch or dinner. Using protein powder in smoothies is another convenient option.