For those engaged in health and performance, recent shifts in nutrition science reflect a long-awaited move toward more practical and evidence-based recommendations, particularly in the area of protein intake.
Current evidence now supports adults aiming for 1.2–1.6 g/kg/day of protein, a meaningful increase from the long-standing benchmark of 0.8 g/kg/day. While this adjustment is certainly a win for trainers, nutrition coaches, and resistance training advocates, it represents only one piece of a much larger conversation. To make a meaningful impact on muscle preservation, metabolic health, and client transformation, we must go beyond merely focusing on daily intake totals. It is crucial to guide clients in understanding how much protein they should consume per meal, the frequency of their intake, and the timing of consumption to promote sustained muscle protein synthesis (MPS) throughout the day, particularly as age and anabolic resistance begin to take effect.
Let’s delve into the details.
Per-Meal Protein Thresholds: 25–40g Is the New Baseline
One of the most consistent findings in protein research emphasizes the importance of achieving a minimum per-meal threshold to stimulate muscle protein synthesis (MPS) effectively. For most adults, this threshold typically ranges from 25 to 30 grams of high-quality protein per meal (Tieland et al., 2017; Paddon-Jones & Rasmussen, 2009).
However, for adults over the age of 30—especially those entering their 40s, 50s, and beyond—research indicates that the optimal threshold is around 0.4g/kg per meal, translating to approximately 30 to 40 grams depending on individual body weight (Baum et al., 2016; Jeong, 2025). This elevated target addresses the increasing phenomenon of anabolic resistance, which refers to the diminished MPS response that accompanies aging.
In simple terms, relying on a total daily intake of 90 grams of protein that is unevenly distributed across meals—such as oatmeal for breakfast, a salad for lunch, and a heavier dinner—may satisfy basic nutritional needs but is insufficient for maintaining muscle mass, metabolism, and overall performance. For clients facing challenges such as weight loss, GLP-1 medication use, or hormonal changes, inadequate protein intake at each meal can further accelerate muscle loss and metabolic decline.
Timing and Distribution: Three Protein-Rich Meals Are Better Than One
Research indicates that evenly distributing protein intake throughout the day—typically through three meals containing 25–40 grams of protein each—profoundly enhances muscle protein synthesis (MPS) compared to patterns where protein consumption is concentrated primarily at dinner (Mamerow et al., 2014; Cardon-Thomas et al., 2017; Smeuninx et al., 2020).
Despite these findings, it may be inferred that many adults tend to consume most of their protein at a single evening meal, while their breakfasts and snacks often consist of refined carbohydrates and little protein. This distribution strategy overlooks multiple opportunities to stimulate MPS, particularly during the day when insulin sensitivity is at its peak.
For clients over 30, particularly women, this presents a valuable coaching opportunity. Educating them about protein pacing not only enhances satiety and appetite regulation but also boosts daily net protein synthesis—an essential factor in preserving lean mass, improving overall function, and achieving body composition goals over time.
Exercise + Protein Timing: An Anabolic Advantage
The relationship between protein intake and resistance exercise is synergistic. Consuming 25–40 grams of high-quality protein within 1–2 hours after exercise has been consistently shown to enhance muscle repair, growth, and long-term hypertrophy (Esmarck et al., 2001; Witard et al., 2016).
However, timing extends beyond just the post-workout window. Ensuring that total daily protein intake is distributed evenly across meals and aligned with periods of muscle stress (such as after workouts) is crucial for optimal long-term adaptations. For aging adults, this dual approach, optimizing protein intake alongside well-timed resistance training, may be the most effective strategy for maintaining independence, metabolic flexibility, and functional strength.
Coaching Takeaways: From Guidelines to Gains
- Elevate the conversation – Move clients away from focusing solely on daily totals and instead teach them the how, when, and why behind protein intake.
- Promote 30–40g protein meals – Build meal templates that prioritize complete proteins, especially at breakfast and lunch, where clients often fall short.
- Time protein around workouts – Reinforce the importance of post-training protein, ideally within a 1–2 hour window, to capitalize on the anabolic window.
- Create muscle-forward routines – Leverage strength training and high-protein diets together, particularly for clients over 30 or on weight-loss medications.
- Reinforce the science – Share simple visual tools, infographics, or examples to illustrate what 30–40g of protein actually looks like.
Why This Matters
As the updated protein targets gain traction, personal trainers are uniquely positioned to translate those recommendations into real-world outcomes. You’re not just coaching macros, you’re preserving muscle mass, enhancing metabolic health, and empowering clients to sustain their transformations beyond the New Year.
By helping clients adopt a muscle-centric, protein-forward routine that integrates per-meal thresholds and precise timing, you’re giving them a blueprint for vitality, not just vanity.
References
Baum, J., Kim, I., & Wolfe, R. (2016). Protein Consumption and the Elderly: What Is the Optimal Level of Intake?Nutrients, 8(6), 359. https://doi.org/10.3390/nu8060359
Cardon-Thomas, D., Riviere, T., Tieges, Z., & Greig, C. (2017). Dietary Protein in Older Adults: Adequate Daily Intake but Potential for Improved Distribution. Nutrients, 9(3), 184. https://doi.org/10.3390/nu9030184
Esmarck, B. et al. (2001). Timing of postexercise protein intake is important for muscle hypertrophy. J Physiol, 535(1), 301–311. https://doi.org/10.1111/j.1469-7793.2001.00301.x
Jeong, S. (2025). The Role of mTOR and AMPK Signaling in Skeletal Muscle Hypertrophy. Cureus. https://doi.org/10.7759/cureus.96018
Mamerow, M. et al. (2014). Dietary Protein Distribution Positively Influences 24-h MPS in Adults. J Nutr, 144(6), 876–880. https://doi.org/10.3945/jn.113.185280
Paddon‐Jones, D., & Rasmussen, B. (2009). Dietary protein recommendations and sarcopenia prevention. Curr Opin Clin Nutr Metab Care, 12(1), 86–90. https://doi.org/10.1097/mco.0b013e32831cef8b
Smeuninx, B., Greig, C., & Breen, L. (2020). Amount, Source and Pattern of Protein Intake Across the Lifespan. Front Nutr, 7. https://doi.org/10.3389/fnut.2020.00025
Tieland, M. et al. (2017). Impact of Dietary Protein on Muscle Mass in Elderly: Meta-analysis of RCTs. J Nutr Health Aging, 21(9), 994–1001. https://doi.org/10.1007/s12603-017-0896-1
Volpi, E. et al. (2012). Optimal Protein Intake for Older Adults: Greater Than RDA? J Gerontol A Biol Sci Med Sci, 68(6), 677–681. https://doi.org/10.1093/gerona/gls229
Witard, O. et al. (2016). Protein Considerations for Skeletal Muscle Mass in Adults. Nutrients, 8(4), 181. https://doi.org/10.3390/nu8040181
