When it comes to hypertrophy training—lifting weights with the goal of increasing muscle size—there’s no nutrient more frequently discussed, misunderstood, and obsessed over than protein. For anyone serious about growing muscle, whether you’re a newcomer to the gym or a seasoned lifter pushing through plateaus, understanding how protein works and how to use it effectively is crucial.
In this article, we’ll explore how protein supports muscle growth, examine the latest research, discuss how much you really need (and when), break down types of protein and their importance, and help you separate supplement hype from real food essentials.
Protein and Muscle Protein Synthesis
Muscle growth occurs when the rate of muscle protein synthesis (MPS) exceeds the rate of muscle protein breakdown (MPB). Resistance training is a powerful stimulus for MPS, but without adequate dietary protein, your muscles won’t have the building blocks—amino acids—necessary for repair and growth.
Protein is made up of 20 amino acids, nine of which are essential (meaning the body cannot produce them). Of particular interest to lifters are the branched-chain amino acids (BCAAs)—leucine, isoleucine, and valine. Leucine especially plays a key role in stimulating MPS via the mTOR pathway, a critical cellular regulator of growth (Atherton & Smith, 2012).
What Does the Research Say?
The science around protein intake and muscle growth is robust. A meta-analysis by Morton et al. (2018) found that protein supplementation significantly enhanced changes in muscle strength and size in individuals engaged in resistance training. The same study concluded that around 1.6 grams of protein per kilogram of body weight per day was sufficient for most people to maximise muscle gains, with little additional benefit beyond 2.2 g/kg.
Another key finding from research is protein distribution. Rather than consuming a large portion at once (e.g., post-training shakes alone), it’s more effective to distribute protein evenly across the day. A study by Areta et al. (2013) demonstrated that 20g of protein consumed every 3–4 hours optimised MPS over a 12-hour post-training window.
Protein Intake: How Much and How Often?
How Much?
Let’s break it down:
- Minimum effective dose: ~1.6 g/kg/day (Morton et al., 2018)
- Upper beneficial range: ~2.2 g/kg/day
- Advanced trainees or in a caloric deficit: up to 2.4–2.6 g/kg/day (Helms et al., 2014)
For a 75kg male:
- Minimum: 120g/day
- Optimal range: 165g/day
- Cutting or advanced: up to 195g/day
How Often?
Aim to consume:
- 0.4–0.55 g/kg of high-quality protein every 3–4 hours, across 4–6 meals per day (Schoenfeld & Aragon, 2018).
Why? Because MPS is a transient response; it spikes after protein consumption and returns to baseline within a few hours. By spacing intake, you maintain an anabolic (muscle-building) environment throughout the day.
Beginners vs. Intermediate vs. Advanced Lifters
Your training experience influences your body’s responsiveness to protein.
Beginners
Beginners often experience “newbie gains,” meaning even moderate resistance training and dietary improvements can lead to rapid muscle growth. Their protein requirements, while still important, are typically easier to meet. 1.6 g/kg/day is usually sufficient.
Intermediate Lifters
With adaptation, gains slow. Protein intake should edge towards the upper recommended range. Training also becomes more intense and structured, increasing muscle damage and recovery needs.
Advanced Lifters
These individuals face diminishing returns. MPS rates may not respond as strongly to training as in novices, making nutrient timing, quality, and quantity increasingly important. They often benefit from:
- 2.2–2.4 g/kg/day, especially during cutting phases.
- More attention to protein quality and distribution.
Types of Protein: It’s Not Just About Quantity
Whole Proteins vs. Isolated Amino Acids
Whole proteins contain all essential amino acids, while isolated amino acids (like BCAAs or EAAs) are often promoted for their targeted effects. While BCAAs—particularly leucine—stimulate MPS, they are insufficient on their own for sustained muscle building.
Why you need variety:
- Different protein sources are digested and absorbed at varying rates. For example:
- Whey protein is rapidly absorbed—ideal post-workout.
- Casein protein digests slowly—ideal before bed.
- Eggs, beef, poultry, soy, dairy provide high biological value (BV) and complete amino acid profiles.
Plant vs. Animal Proteins
Plant proteins (e.g., lentils, quinoa, peas) often lack one or more essential amino acids or are absorbed less efficiently. However, combining sources (e.g., rice and beans) can form complete profiles. Research by Gorissen & Witard (2018) suggests plant-based athletes may need to consume slightly more protein—+10%–20%—to achieve comparable MPS to omnivores.
Rich Protein Sources: Eat Real Food First
Here’s a quick guide to high-protein whole foods:
| Food | Protein (per 100g) |
| Chicken breast | 31g |
| Turkey | 29g |
| Lean beef | 26g |
| Eggs (whole) | 13g |
| Greek yoghurt (plain) | 10g |
| Cottage cheese | 11g |
| Salmon | 25g |
| Lentils (cooked) | 9g |
| Tofu | 8g |
| Tempeh | 19g |
| Quinoa (cooked) | 4g |
Whole foods not only provide protein but also vital micronutrients, fats, and fibre—all of which support overall health and performance.
Protein Supplements: Use with Purpose
Supplements like whey, casein, and plant-based powders offer convenience and rapid absorption, but they shouldn’t replace real food. Consider them a tool, not a foundation.
Benefits of Protein Supplements:
- Easy post-workout option
- Measured doses
- Low-fat/low-carb (ideal during cutting)
- Helpful for vegetarians/vegans
Why Whole Foods Should Come First:
- Greater satiety from solid foods
- Micronutrient density
- Diet sustainability and enjoyment
- Digestive health (fibre, gut flora)
Over-reliance on shakes can lead to nutritional gaps. Ideally, limit to 1–2 servings of supplemental protein per day, with the rest from diverse, whole sources.
Final Thoughts: It’s More Than Just Hitting Numbers
Meeting your protein needs is essential for muscle growth, but context matters. You can hit your macro goals and still fall short if you ignore quality, timing, or overall energy balance. For hypertrophy:
- Lift progressively and intelligently.
- Eat enough calories to support training and recovery.
- Prioritise protein quality and distribution.
- Don’t underestimate sleep, stress, and consistency—they matter just as much.
Protein isn’t a magic bullet. But with the right approach, it’s a powerful ally in your muscle-building journey.
References
- Atherton, P. J., & Smith, K. (2012). Muscle protein synthesis in response to nutrition and exercise. The Journal of Physiology, 590(5), 1049–1057. https://doi.org/10.1113/jphysiol.2011.225003
- Areta, J. L., et al. (2013). Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. The Journal of Physiology, 591(9), 2319–2331. https://doi.org/10.1113/jphysiol.2012.244897
- Gorissen, S. H., & Witard, O. C. (2018). Characterising the muscle anabolic potential of dairy, meat and plant-based protein sources in older adults. Proceedings of the Nutrition Society, 77(1), 20–31. https://doi.org/10.1017/S0029665117001940
- Helms, E. R., et al. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 11(1), 20. https://doi.org/10.1186/1550-2783-11-20
- Morton, R. W., et al. (2018). 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. British Journal of Sports Medicine, 52(6), 376–384. https://doi.org/10.1136/bjsports-2017-097608
- Schoenfeld, B. J., & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 15(1), 10. https://doi.org/10.1186/s12970-018-0215-1