How much protein do you really need to eat?

A recommendation that is almost unanimous

If there is one piece of advice that runs through every conversation about strength training, it is this: “eat more protein”. Whether the goal is to build muscle mass, lose fat or simply improve recovery, protein sits at the centre of almost every nutritional recommendation.

But one question remains: how much should you actually consume? The answers vary enormously. Some recommend 1 g per kilogram of body weight, while others insist you must always exceed 2.5 g/kg, or even 3 g/kg. Conversely, recommendations aimed at the general population often remain well below these values.

Faced with these conflicting messages, it becomes difficult to distinguish real needs from habits popularised on social media. Fortunately, the scientific literature is now much clearer. Thanks to several meta-analyses pooling dozens of intervention studies, it is now possible to estimate with good precision the amount needed to maximise the adaptations linked to training.

The answer nonetheless depends on several factors: training level, the goal being pursued, overall energy intake, age, and the quality of the protein consumed. The aim, then, is not to chase the highest possible number, but to identify the amount that is sufficient to progress, without falling into unnecessary excess.

Why is protein so important?

Protein supplies the amino acids needed to repair and build muscle tissue. After a resistance training session, muscles undergo numerous micro-adaptations.

To respond to this stimulus, the body temporarily increases muscle protein synthesis, a process essential to developing new contractile proteins. However, this synthesis can only be sustained if enough amino acids are available. An insufficient intake progressively limits the body's ability to efficiently rebuild the tissue that has been worked.

Conversely, continually increasing protein beyond requirements does not lead to unlimited muscle growth. Like many biological phenomena, the relationship follows a law of diminishing returns: once needs are met, additional benefits become increasingly small.

What the research shows

For a long time, recommendations were based mainly on observing the eating habits of athletes. Today, several meta-analyses allow for a much more solid answer.

Work led notably by Morton and colleagues, pooling dozens of intervention studies, shows that around 1.6 g of protein per kilogram of body weight per day is already enough to maximise muscle gains in most trainees.

This figure is not an absolute ceiling. Some people may gain a slight benefit from somewhat higher intakes, which is why many scientific bodies now recommend a range of 1.6 to 2.2 g/kg/day. Beyond that, the benefits for hypertrophy generally become very small, if not non-existent, in people who are already eating enough energy and following a suitable training programme.

In other words, training quality and dietary consistency often influence results more than a continual increase in protein.

Once needs are met, it is no longer the amount of protein that drives progress, but the consistency of training and the regularity of eating.

Do needs change depending on the goal?

The optimal amount of protein also depends on context. During a muscle-gain phase, an intake within the recommended range is generally enough to effectively support muscle growth.

During fat loss, however, the situation changes. The energy deficit increases the risk of losing some of the muscle mass already gained. In this context, a slightly higher intake can help better preserve muscle while supporting recovery.

Older adults also have specific needs. With age, muscle sensitivity to protein progressively decreases, a phenomenon known as anabolic resistance. To achieve a comparable stimulation of protein synthesis, they often benefit from a slightly higher intake as well as a distribution adapted across the day.

The recommendation therefore does not depend solely on body weight: it must also take into account physiological status and the goals being pursued.

Is all protein equal?

Total quantity remains the most important factor, but the quality of protein also deserves consideration. Proteins differ in digestibility and in their content of essential amino acids, particularly leucine, which plays a major role in activating muscle protein synthesis.

Animal proteins generally offer a complete amino acid profile and high digestibility. Plant proteins can also cover requirements when consumed in sufficient quantity as part of a varied diet.

This is precisely why it is preferable to assess the diet as a whole rather than a single food. In practice, total daily intake matters far more than the choice of a single protein source.

Does the distribution of protein throughout the day matter?

For many years, attention focused almost exclusively on the famous “post-workout timing”. The idea that protein absolutely had to be consumed within minutes of the last set contributed heavily to the success of the “anabolic window” concept.

Current research paints a more nuanced picture. While consuming protein after training remains a good habit, the total amount ingested over the day influences results far more than the precise timing of consumption.

That does not mean distribution is unimportant, however. Muscle protein synthesis rises after a protein-rich meal, then gradually returns to baseline. Spreading intake across several meals therefore stimulates this process repeatedly throughout the day rather than concentrating all protein into a single meal.

For most trainees, three to five meals each containing a sufficient amount of protein represent a simple and effective strategy.

The most common mistakes

One of the most widespread mistakes is believing that more protein automatically leads to more muscle. Once needs are met, continually increasing intake generally brings very little additional benefit for hypertrophy.

Another mistake is focusing solely on protein while neglecting the other parameters of progress. Insufficient training, poor-quality sleep or too low an energy intake will limit adaptations, even with a very protein-rich diet.

Some people also believe that only supplements can help reach the recommendations. In reality, a varied diet is often enough to cover daily needs. Protein powders are simply a convenient solution when it becomes difficult to reach a target from food alone.

Finally, many think only in terms of grams per day. Expressing intake in grams per kilogram of body weight generally gives a more meaningful recommendation.

Practical recommendations

Aim for 1.6 to 2.2 g of protein per kilogram of body weight per day.

Spread this intake across three to five meals throughout the day.

Prioritise protein-rich foods and use supplements only when necessary.

During a calorie deficit, an intake at the upper end of the recommendation can help preserve muscle mass.

Assess your diet as a whole rather than focusing on a single meal or food.

Conclusion

Protein plays an essential role in building muscle mass, but its role is now much better understood than it was a few years ago. Research shows that it is not necessary to keep increasing intake in order to keep progressing.

For the vast majority of trainees, a daily intake of between 1.6 and 2.2 g/kg of body weight, combined with well-structured training, largely covers the needs for hypertrophy. Beyond that amount, benefits generally become marginal.

Progress depends above all on the consistency between training, nutrition, recovery and regularity over several months. Ultimately, the best strategy is not to consume as much protein as possible: it is to consume enough, consistently, within a coherent overall programme.