How much protein do I need to regain muscle?

October 11, 2025 •

5 min read

Adults can lose 4 to 6 pounds of muscle per decade without regular strength training, making adequate nutrition, particularly protein intake, crucial for recovery and rebuilding. Understanding how much protein do I need to regain muscle is key to reversing this trend, supporting tissue repair, and improving overall strength and health.

Quick Summary

This guide provides comprehensive, research-backed recommendations on protein intake for muscle regrowth. It outlines how to calculate optimal daily amounts based on activity level, age, and body composition, alongside advice on effective nutrient timing and the best dietary sources for stimulating muscle repair.

Key Points

Daily Intake is Key: For active individuals, aiming for 1.6–2.2 grams of protein per kilogram of body weight daily is most effective for muscle regrowth.
Older Adults Need More: Individuals over 65 have higher protein needs (1.2–1.5 g/kg/day) due to anabolic resistance, requiring more protein to trigger muscle repair.
Distribute Your Intake: Spreading protein evenly across 3-4 meals (0.4–0.55 g/kg per meal) is more effective for sustaining muscle protein synthesis throughout the day than consuming it in just one or two large meals.
High-Quality Sources Matter: Prioritize complete protein sources, such as whey, casein, eggs, and lean meats, for their optimal amino acid profiles, especially high leucine content.
Resistance Training is Crucial: Protein alone is not enough; resistance training provides the essential stimulus to create micro-tears that signal muscles to repair and grow stronger.
Optimize Recovery: Timing protein consumption within a few hours of exercise, maintaining overall hydration, and getting enough sleep are all critical components of a successful muscle regrowth strategy.

The Core Role of Protein in Muscle Regrowth

Protein is the foundational building block for muscle tissue, and its importance is amplified during periods of muscle atrophy or injury recovery. Intense exercise or trauma creates tiny micro-tears in muscle fibers. The body's repair response is to use the amino acids from ingested protein to patch up this damage. This process, known as muscle protein synthesis (MPS), is what ultimately leads to stronger, larger muscles. For muscle regrowth to occur, the rate of MPS must exceed the rate of muscle protein breakdown (MPB) over time. Without sufficient protein, your body lacks the raw materials to effectively repair and rebuild, slowing down recovery and limiting gains.

Calculating Your Individual Protein Requirements

While the standard Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight, this is merely the minimum to prevent deficiency and is insufficient for active individuals seeking to regain muscle. Your specific needs are influenced by age, activity level, and overall health.

Here are the recommended protein intake ranges:

For Healthy, Active Adults: Aim for 1.6–2.2 grams of protein per kilogram of body weight per day. This range supports maximal muscle protein synthesis when combined with resistance training.
For Older Adults (65+): Due to a phenomenon called "anabolic resistance," older individuals' bodies are less responsive to protein's anabolic effects and require more to stimulate muscle growth. A target of 1.2–1.5 grams of protein per kilogram of body weight per day is recommended to counteract age-related muscle loss (sarcopenia) and rebuild muscle effectively. During periods of illness or inactivity (e.g., bed rest), needs may increase further, up to ≥1.6 g/kg/d.
For Overweight or Obese Individuals: Using total body weight for calculation can lead to unnecessarily high protein intake. A better approach is to use your target body weight or calculate based on lean body mass (LBM). For example, a 90kg individual with 20% body fat has 72kg of LBM, resulting in a target of 158g of protein per day at the 2.2 g/kg LBM rate. For fat loss while preserving muscle, 1.6–2.4 g/kg/day is recommended.
For Injury Recovery: When healing from an injury, your body's protein requirements increase significantly to repair damaged tissues. Needs can rise to 1.2–1.5 grams per kilogram of body weight per day to support the protein-intensive rebuilding process.

Protein Timing and Distribution: Is There a 'Magic Window'?

For years, the concept of a tight "anabolic window" immediately post-workout dominated fitness advice, suggesting a short, 30-60 minute period was crucial for consuming protein. However, recent research shows this window is much broader, potentially lasting several hours after exercise. For most, prioritizing total daily protein intake is more important than rigidly timing every gram.

Nevertheless, distributing your protein intake effectively throughout the day offers distinct benefits:

Optimal Distribution: Spreading protein evenly across 3-4 meals daily, with each meal containing 0.4–0.55 grams of protein per kilogram of body weight, may maximize MPS responses. This strategy prevents the body from being over-saturated at one meal and undersupplied at another.
Post-Workout Fuel: While not as time-sensitive as once thought, consuming 20-40 grams of high-quality protein within a few hours post-exercise effectively kickstarts muscle repair and recovery.
Pre-Bed Consumption: Having a slow-digesting protein source like casein before sleep can elevate protein synthesis overnight, aiding recovery during an extended fasting period.

Comparison of Protein Requirements by Population


Population	Protein Requirement (g/kg/day)	Considerations
Sedentary Adult	~0.8	Minimum to prevent deficiency, insufficient for active lifestyles.
Healthy Active Adult	1.6–2.2	Ideal range for stimulating muscle growth with resistance training.
Older Adult (>65)	1.2–1.5	Increased needs due to anabolic resistance and muscle loss prevention.
Injury Recovery	1.2–1.5+	Higher needs to facilitate tissue repair during healing.
Overweight/Obese	1.6–2.4	Calculated based on lean body mass to avoid overestimation during fat loss.

The Best Protein Sources for Muscle Repair

Both animal and plant-based protein sources can be effective, but their amino acid profiles differ. High-quality sources are rich in all nine essential amino acids, especially leucine, a key activator of MPS.

Top Animal-Based Protein Sources:

Whey Protein: A fast-digesting milk protein with the highest leucine content, ideal for post-workout shakes.
Casein Protein: A slow-digesting milk protein that provides a sustained release of amino acids, perfect for a pre-sleep snack.
Eggs: A complete protein source, and studies show consuming whole eggs promotes greater MPS than egg whites alone.
Chicken Breast: A classic lean protein source packed with high-quality protein.
Salmon: Rich in both protein and omega-3 fatty acids, which aid in muscular health.
Greek Yogurt: Contains both whey and casein protein, offering both fast and slow absorption.
Lean Beef: Provides quality protein, B vitamins, and creatine.

Top Plant-Based Protein Sources:

Soybeans & Tofu: Soy is a high-quality plant protein, providing a robust MPS response.
Lentils & Beans: Excellent sources of protein, fiber, and important micronutrients. Combining them with other foods can create a complete amino acid profile.
Quinoa: One of the few complete plant-based proteins.
Protein Powders: High-quality vegan protein powders, often from blends of pea and rice, are excellent for supplementation.

The Indispensable Role of Resistance Training

Dietary protein is only one side of the muscle-regrowth equation; resistance training is the catalyst. You must provide a stimulus that challenges your muscles to encourage them to rebuild stronger. The intensity of exercise directly influences MPS, with higher-intensity workouts leading to greater synthesis. For most adults, a regimen of progressive resistance training—gradually increasing the weight, reps, or sets—is essential for significant muscle regrowth. This combination of stress and proper nutrition is the fundamental strategy for rebuilding muscle mass.

The Final Word on Regaining Muscle Mass

Regaining muscle requires a multi-faceted approach centered on consistent, high-quality protein intake and regular resistance training. The specific protein target will depend on your individual circumstances, including age, weight, and activity level. For an average active adult, aiming for 1.6–2.2 g/kg/day is a strong starting point, distributed across several meals. Prioritizing complete protein sources and ensuring adequate overall caloric intake and hydration will create the optimal internal environment for your body to repair and rebuild muscle efficiently. Consult a healthcare professional to tailor a plan specifically for your needs, especially during recovery from injury or with underlying health conditions like sarcopenia.

For more detailed information on protein intake guidelines and calculators, consider resources from reputable organizations in sports nutrition like Examine.com, an evidence-based resource on supplements and nutrition.

Conclusion

To successfully regain muscle, focus on consuming a daily protein intake significantly higher than the standard RDA, typically in the range of 1.6–2.2 grams per kilogram of body weight for active individuals. Distributing this protein evenly throughout the day, choosing high-quality sources, and consistently engaging in resistance training are the most effective strategies for stimulating and sustaining muscle protein synthesis. With patience and a strategic approach, it is entirely possible to restore and even increase your muscle mass and strength.

Frequently Asked Questions

While the standard RDA is 0.8 g/kg/day, research shows that active individuals and those trying to regain muscle need significantly more, typically starting around 1.2 g/kg/day, with optimal intake being higher.

Yes. Older adults experience 'anabolic resistance,' which means their bodies are less sensitive to the muscle-building effects of protein. This necessitates a higher protein intake, often recommended at 1.2–1.5 g/kg/day, to effectively stimulate muscle protein synthesis.

While it was once believed that there was a narrow 'anabolic window' immediately post-exercise, research now suggests the total daily protein intake is more important. However, consuming high-quality protein within a few hours of training and distributing intake across meals can still be beneficial.

Animal-based proteins are generally considered higher quality because they contain all essential amino acids and are rich in leucine. Plant-based proteins can be highly effective, especially when combining different sources (e.g., rice and beans) to create a complete amino acid profile.

While protein powders like whey and casein are convenient and effective for boosting intake, relying solely on supplements is not recommended. Whole food sources provide additional micronutrients, vitamins, and minerals that are crucial for overall health and recovery.

For healthy individuals, consuming protein above the optimal range is generally safe, though it may not offer additional muscle-building benefits and could lead to fat storage if total calories are excessive. People with pre-existing kidney disease should consult a doctor before increasing protein significantly.

Exercise is arguably the most powerful factor. Protein provides the building blocks, but resistance training creates the stimulus for muscle growth and repair. Without consistent strength training, muscle regrowth is not possible.