What does New Evidence say about Protein Intake?

Protein, the cornerstone of nutrition, has long been hailed as the building block of life. From muscle repair to hormone production, its role in our body's functionality is indispensable. However, amidst the maze of dietary advice, understanding the significance of protein can be challenging. Interesting, the science around the timing of consumption is changing! Which could switch things up for athletes. In this blog, we embark on a journey to unravel the mysteries of protein, exploring its benefits, sources, and the myths surrounding its consumption.

What you will learn in this blog:

1. What is protein?
2. Why do we need protein?
3. What are the sources of protein?
4. How much and how often should you eat protein? (New evidence!)

What is Protein?

Proteins are chains made up of building blocks called amino acids. The body uses 20 different types of amino acids, each one having its own function. Eleven of those amino acids can be made in the body and can also be provided by the diet. However, nine amino acids cannot be made in the body and therefore must be obtained through the diet.

Why do we need Protein?

Protein is not just another macronutrient; it's the fundamental component of every cell in the body. It plays a pivotal role in building and repairing tissues, synthesizing enzymes and hormones, and supporting immune function.

Without an adequate intake of protein, our bodies cannot function optimally, leading to a host of health issues such as muscle loss, weakened immune system, and impaired wound healing.

1.  Muscle Growth and Repair

One of the primary benefits of protein for athletes is its ability to facilitate muscle repair and growth. During intense training sessions, muscles undergo stress and micro-tears. Protein provides the essential amino acids necessary for muscle protein synthesis, the process through which muscles repair and rebuild themselves. By consuming protein-rich foods or supplements post-exercise, athletes can accelerate recovery and promote muscle hypertrophy, enhancing strength and performance over time.

2.  Enhanced Strength and Power

Protein intake has been linked to improvements in strength and power output, crucial attributes for athletes across various disciplines. Research suggests that consuming protein before or after resistance training sessions can enhance muscle protein synthesis, leading to gains in muscular strength and power. This translates to improved performance in activities requiring explosive movements, such as sprinting, jumping, and weightlifting.

3. Faster Recovery

Recovery is a critical aspect of athletic training, as it allows the body to adapt to the stress imposed during exercise and maximize performance gains. Protein consumption post-exercise has been shown to expedite recovery by aiding the replenishing of glycogen stores, reducing muscle soreness, and promoting tissue repair. Additionally, the amino acid leucine, abundant in many protein sources, plays a crucial role in stimulating muscle protein synthesis, further enhancing recovery and adaptation to training stimuli.

What are the sources of Protein?

As mentioned above, some protein sources contain all nine essential amino acids – we call these complete proteins. Protein sources that do not contain all nine are called incomplete proteins.

To make incomplete proteins complete, you must pair them together. Previous research suggested that you must pair them together in the same meal, but now we know that you only need to pair them in meals close together. Example: old research = bean on toast || new research = toast at breakfast and beans at lunch. Of course, you can still have beans on toast, you just don’t NEED to pair incomplete proteins at every meal.

How much and how often should we eat protein?

The current recommendations for sports nutrition call for breaking up protein consumption throughout the day into numerous equal meals. The theory behind protein distribution is mostly based on research indicating that muscle protein synthesis—the process by which muscles repair and adjust to training—can only use a certain quantity of protein consumed in a single meal.

Previously, it was thought that muscle protein synthesis increases steadily with protein doses up to around 20 grams. Beyond this point, increasing the dose further to 40 grams was believed to provide only a modest additional benefit of about 10-20%.

However, a recent study in 2023 investigated the effects of 0, 25, and 100 g of protein immediately after whole-body resistance exercise in healthy young adults over a 12-h measuring period.

This graphic displays the results of the study.

To summarize the results, While the 25-gram dose had nearly completed digestion and absorption after 6 hours, the 100-gram protein dose was still undergoing digestion after 12 hours. The 100-gram dose led to a 19% increase in muscle protein synthesis rates over the initial 4 hours compared to the 25-gram dose, and over the entire 12-hour period, it resulted in a 30% higher muscle protein synthesis rate compared to the 25-gram dose.

So how should you apply this information to your diet?

The researchers who conducted this study concluded with the following pieces of advice:

1. Stating that protein distribution offers no additional benefits would be premature as we currently lack sufficient evidence. While ensuring a reasonably balanced protein distribution doesn't require much effort, obsessing over the specifics may not be worthwhile.

2. If your next meal is in the next 5 hours, consume at least 20 g.

3. If your next meal is not in the next 5 h, it is recommended to consume at least 40 g.

4. Even easier: just focus on your total daily protein intake. That will likely give you most or even all the benefits without much stress.

Just to emphasize, this is new evidence from one study, so with further research this information may changer even more! However, it an emerging area of research in which we can likely expect to see similar results overtime.

Conclusion

Protein is vital for our bodies, supporting everything from muscles to hormones. Recent findings, especially on when to eat protein, could change how athletes plan their diets. We've covered what protein is, why it's important, and where to find it. We've also learned about new research showing how the timing and amount of protein can affect muscle growth. This study suggests that having 20 grams of protein if your next meal is soon, or 40 grams if it's not, could be helpful. But don't stress too much about it; just aim for enough protein each day. Remember, this is just one study, so more research might refine these ideas. But it's exciting to see how science is evolving and how it can help us improve our performance and health.

Summary of Learnings:

1. Proteins are chains made up of building blocks called amino acids. We need to get nine of these amino acids from our diets. Some sources contain all nine (mostly animal products) and some do not. Food that do not must be paired together to make complete proteins.
2. We need protein for important functions such as muscle function and repair, building strength and power, and enhancing recovery from exercise.
3. Previously, it was thought that muscle protein synthesis increases steadily with protein doses up to around 20 grams. Beyond this point, increasing the dose further to 40 grams was believed to provide only a modest additional benefit of about 10-20%
4. A new study has suggested that a 25-gram dose of protein can be digested and absorbed after 6 hours whereas, a 100-gram protein dose still undergoes digestion after 12 hours. The 100-gram dose led to a 19% increase in muscle protein synthesis rates over the initial 4 hours compared to the 25-gram dose, and over the entire 12-hour period, it resulted in a 30% higher muscle protein synthesis rate compared to the 25-gram dose.

REMOVE THE GUESS WORK

References

1. Trommelen J, van Lieshout GAA, Nyakayiru J, Holwerda AM, Smeets JSJ, Hendriks FK, van Kranenburg JMX, Zorenc AH, Senden JM, Goessens JPB, Gijsen AP, van Loon LJC. The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell Rep Med. 2023 Dec 19;4(12):101324. doi: 10.1016/j.xcrm.2023.101324. PMID: 38118410; PMCID: PMC10772463.

2. Phillips SM, Van Loon LJ. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci. 2011;29 Suppl 1:S29-38.

3. Macnaughton LS, Wardle SL, Witard OC, McGlory C, Hamilton DL, Jeromson S, Lawrence CE, Wallis GA, Tipton KD. The response of muscle protein synthesis following whole-body resistance exercise is greater following 40 g than 20 g of ingested whey protein. Physiol Rep. 2016 Aug;4(15):e12893.