How important is it to hit the exact 1.6-2.2 g/kg protein range?

While 1.6-2.2 g/kg is considered optimal, falling slightly short (e.g., 1.3-1.5 g/kg) does not necessarily lead to a dramatic drop in muscle gains. The difference between 'pretty sufficient' and 'fully optimal' is often very slim and not worth significant stress.

What does the latest research say about protein intake and muscle mass?

Recent meta-analyses suggest that while higher protein intake generally supports greater lean body mass gains, the effect size diminishes significantly beyond a certain threshold. Protein's primary role is permissive, enabling gains driven by resistance training.

Can protein intake have a negative effect size on muscle growth?

Studies where protein intake was very low (under 1.2 g/kg) showed a slightly negative effect size, but this was generally interpreted as near-zero, not indicating significant muscle loss. Very high protein levels also become redundant, showing a plateau effect.

Does it matter if I'm vegan when considering protein intake for muscle growth?

For strict vegans, maintaining protein intake at or above 1.6 g/kg of total body weight is generally recommended to achieve results similar to omnivores. If intake is lower, focusing on high-quality vegan protein sources becomes more crucial.

How should I adjust protein intake if I have a lot of body fat?

When scaling protein by total body mass, recommendations like 1.6 g/kg can lead to excessively high intake for individuals with higher body fat percentages. Scaling protein intake based on fat-free mass (1.5-2.0 g/kg FFM) can be a more appropriate approach in these cases.

Is it worth stressing over hitting the exact upper limit of protein recommendations?

No, it's generally not worth obsessing over the absolute highest protein intake numbers. If achieving slightly lower intake (e.g., 1.4-1.5 g/kg) is challenging or unpleasant, the potential loss in gains is minimal, and the stress may be more detrimental.

Key Moments

How much protein do you actually need for muscle growth?

Stronger By Science

Sports4 min read45 min video

Oct 28, 2022|12,389 views|445|102

Save to Pod

Key Moments

TL;DR

Protein is crucial for muscle growth, but optimal intake may be less precise than commonly believed.

Key Insights

Total calorie intake and protein intake are the two most important dietary metrics for hypertrophy.

While 1.6-2.2 g/kg protein is an effective range, slightly lower intakes (e.g., 1.3-1.5 g/kg) may still yield significant gains.

Resistance training is the primary driver of muscle growth; protein plays a permissive role.

There's an overestimation of the negative consequences of falling slightly below the 'optimal' protein range.

For vegans, maintaining sufficient protein quality and intake above 1.6 g/kg is more critical due to potential bioavailability differences.

Focusing excessively on minute protein adjustments can detract from more impactful training and sleep factors.

FUNDAMENTAL DIETARY METRICS FOR HYPERTROPHY

When pursuing muscle growth (hypertrophy) or body recomposition, the two most critical dietary components to monitor are total calorie intake and protein intake. While calories dictate energy balance, influencing weight and fat fluctuations, protein is essential for muscle repair and synthesis. Restricting protein to very low levels is detrimental to muscle-building efforts. For many individuals focused on body composition, meticulously tracking carbohydrate and fat ratios is often less crucial than ensuring adequate total calories and sufficient protein.

THE EVIDENCE ON PROTEIN INTAKE RANGES

A widely recommended protein intake for muscle growth is between 1.6 to 2.2 grams per kilogram of body weight per day, or approximately one gram per pound. However, recent research, including a meta-analysis by Nunes et al., suggests that while higher protein intake generally correlates with better lean mass gains, the effect size diminishes significantly as intake increases beyond a certain point. The benefits of intakes between 1.2 and 1.59 g/kg are still positive, though less pronounced than intakes above 1.6 g/kg.

INTERPRETING META-ANALYSES AND EFFECT SIZES

A meta-analysis by Morton et al. from 2018 identified a breakpoint around 1.6 g/kg for maximizing muscle gains, but the confidence intervals for this breakpoint were wide, spanning a broad range of intakes. Further analysis, including stress-testing the data by removing outliers or adjusting the x-axis cutoffs, suggests that the difference in lean mass gains between intakes slightly below 1.6 g/kg (e.g., 1.3-1.5 g/kg) and the optimal range is often marginal. Effect sizes in studies with very low protein intake (under 1.2 g/kg) are typically non-significant or even slightly negative, indicating that very low protein is indeed suboptimal.

THE PERMISSIVE ROLE OF PROTEIN IN MUSCLE GROWTH

It is crucial to understand that resistance training is the primary stimulus for muscle growth. Protein intake, while necessary, acts primarily as a 'permissive' factor, enabling the gains stimulated by training to materialize. The concern that falling slightly short of the 1.6-2.2 g/kg range will lead to drastically reduced muscle gains is often an overestimation. Protein restriction to very low levels is detrimental, but once sufficient intake is achieved to support the training stimulus, further increases may offer diminishing returns.

STRESS-TESTING PROTEIN TARGETS AND PRACTICAL RANGES

The exact precision of the 1.6 g/kg threshold is often overstated. Stress-testing the data by examining intakes above 1.2 g/kg or by removing influential data points reveals that the relationship between protein intake and fat-free mass gains becomes less pronounced and explains a smaller percentage of the variance. The practical takeaway is that for individuals who find reaching 1.6 g/kg challenging, inconvenient, or unpleasant, settling for intakes around 1.3-1.5 g/kg may not significantly hinder progress, and the 'juice' may not be worth the 'squeeze' for that marginal potential gain.

CONSIDERATIONS FOR 'PRETTY DAMN GOOD' VS. 'OPTIMAL' INTAKE

A 'pretty damn good' protein intake, where one is likely getting the lion's share of accessible gains without fully optimizing, can be considered 1.2 to 1.6 g/kg total body weight. Scaling this to fat-free mass suggests roughly 1.5 to 2 g/kg. The 'optimal' range, aiming to leave no gains on the table, remains 1.6 to 2.2 g/kg total body weight, or 2 to 2.75 g/kg of fat-free mass. For strict vegans, maintaining protein quality and aiming for at least 1.4 g/kg or closer to 1.6 g/kg is advisable due to potential differences in amino acid profiles and bioavailability.

AVOIDING OBSESSION AND FOCUSING ON THE BIG PICTURE

There is a pervasive misconception that deviating slightly from the optimal protein range has severe negative consequences. This can lead to undue stress and anxiety, which may be more detrimental than the minor protein deficit. Individuals should question the magnitude of benefit from obsessing over small adjustments. Instead of dreading not hitting a precise number, it's more productive to focus on consistent training, adequate sleep, and ensuring protein intake is sufficient to support training stimulus, rather than striving for an often-arbitrary line in the sand.

Mentioned in This Episode

●Supplements

●Software & Apps

Practical Protein Intake Guidelines

Practical takeaways from this episode

Do This

Track total calorie and protein intake for body composition goals.

Aim for 1.2-1.6 grams of protein per kilogram of total body weight for good results.

Consider 1.6-2.2 grams per kilogram of total body weight for optimal gains, leaving no gains on the table.

For fat-free mass scaling, aim for 1.5-2.0 g/kg (good) or 2.0-2.75 g/kg (optimal).

If following a strict vegan diet and aiming for lower protein intake (<1.6 g/kg), focus on high-quality vegan protein sources like soy or mycoprotein.

If you enjoy exploring minor fitness details and supplements, do so out of curiosity, not dread.

If gaining muscle, prioritize consistent resistance training as the primary driver of growth.

Avoid This

Don't severely restrict protein intake if trying to build or maintain muscle.

Don't drastically overestimate the downsides of falling slightly below the 'optimal' protein range (e.g., 1.4-1.5 g/kg vs 1.6-2.2 g/kg).

Don't lose sleep over minor protein intake differences; the lost sleep could be more detrimental.

Don't apply the same obsessive mindset to obtaining marginal gains from supplements as you might to protein intake if the effects are small.

Don't feel pressured to hit the highest protein targets if it's genuinely challenging, infeasible, or unpleasant; the 'juice is not worth the squeeze' for small theoretical gains.

Don't assume that a specific protein intake number is a precise cutoff; the relationship is often more nuanced.

Protein Intake and Lean Body Mass Gains (Nunes et al., 2022)

Data extracted from this episode

Protein Intake (g/kg/day)	Effect Size (Standardized Mean Difference)	Notes
< 1.2	-0.14	Not statistically significant, interpreted as near-zero effect on lean mass gains.
1.2 - 1.59	0.17	Slightly positive effect size, on the borderline of trivial.
≥ 1.6	0.3	Highest effect size, indicating better outcomes for lean body mass.

General Protein Intake Recommendations for Muscle Growth

Data extracted from this episode

Category	Protein Intake (g/kg total body mass)	Protein Intake (g/kg fat-free mass)
RDA (Reference)	0.8	N/A
Pretty Damn Good	1.2 - 1.6	1.5 - 2.0
Optimal (Leave no gains on the table)	1.6 - 2.2	2.0 - 2.75

Common Questions

The widely discussed range for optimal muscle growth is 1.6 to 2.2 grams of protein per kilogram of body weight per day. This range is suggested to maximize gains and leave no potential muscle-building opportunities on the table.