Protein Intake per Kilogram: How Much Is Enough, How Much Is Too Much?

Protein is often described as the building block of muscle, but its role goes far beyond that. Protein is involved in almost every process in the human body. So does eating more protein automatically make us more muscular and healthier? In this article, I summarize the most up-to-date and comprehensive scientific research to answer a simple question: how much protein is enough, and how much is too much?

Protein requirements are calculated per kilogram of body weight. The portion shown is illustrative.

What does the research say?

One of the most comprehensive and recent analyses on this topic is a systematic review and meta-analysis examining 74 randomized controlled trials. The results show that increasing daily protein intake supports gains in muscle mass. Specifically, consuming 1.6 grams of protein per kilogram of body weight per day or more leads to small but statistically significant increases in muscle mass in young adults who perform resistance training. The authors also emphasize that studies investigating the effects of protein intake alone—without resistance exercise—in healthy individuals are very limited (1).

Another recent review focusing on older adults examined the role of protein intake in maintaining muscle and bone health. The findings suggest that increasing protein intake alone does not significantly improve muscle strength, physical performance, or bone health. However, when combined with regular exercise, higher protein intake does lead to positive outcomes. With exercise, consuming more than 1 gram of protein per kilogram of body weight per day is associated with meaningful improvements in muscle mass, leg strength, and physical performance. Overall, protein intakes of at least 1 gram per kilogram per day, and ideally between 1.2 and 1.5 grams per kilogram, are recommended for older adults (2).

A comprehensive systematic review covering the literature from the past 20 years found that increasing protein intake above 1.2 grams per kilogram per day, when combined with resistance training, results in significant gains in lean body mass. While no clear overall relationship was found between total protein intake and cardiovascular disease risk, protein source appears to be a key factor. Processed meat consumption is associated with increased cardiovascular risk, whereas higher intake of plant-based protein is linked to reduced risk. For individuals with healthy kidneys, protein intakes between 1.2 and 1.6 grams per kilogram per day are considered safe. However, in people with impaired kidney function, intakes above 1.6 grams per kilogram may increase renal workload (3).

A review published in 2025 defines protein intakes above 1.6 grams per kilogram per day as “excessive.” For healthy adults, a range of 0.8–1.2 grams per kilogram per day is considered sufficient to support muscle repair, immune function, and metabolic balance. The body cannot store excess protein once its needs are met. Surplus protein is converted in the liver into glucose or fat and used for energy or stored as fat. According to the review, excessive protein intake does not provide additional benefits; instead, it creates metabolic burden and may cause harm over the long term. Therefore, while 0.8–1.2 grams per kilogram per day is considered optimal for the general population, intakes of up to 1.6 grams per kilogram are regarded as safe for physically active individuals (4).

Fitness Gurusu’s Perspective

The four sources summarized here are not small, isolated studies. They are systematic reviews and meta-analyses that evaluate hundreds of studies together, representing the highest level of scientific evidence available. The common conclusion across all of them is clear: protein intake alone does not produce meaningful results. The real benefits consistently emerge from the combination of adequate protein intake and resistance training.

Even without a muscle-building goal, paying attention to protein intake matters, because protein is essential not only for muscle tissue but also for immune function, hormone production, cellular repair, and overall metabolic health. For the general population, 0.8–1.2 g/kg per day is sufficient. Healthy individuals who perform regular resistance training may gain additional benefits by increasing intake up to 1.6 g/kg per day.

Let’s put these numbers into context:

• A 75 kg adult who does not exercise and targets 1 g/kg of protein would need about 75 g of protein per day. This can easily be achieved with 2 eggs (12 g), 150 g of chicken breast (40 g), and 5 meatballs (26 g).

• A 75 kg adult who performs regular resistance training and targets 1.6 g/kg would need about 120 g of protein per day. This could be achieved with 4 eggs (24 g), 250 g of chicken breast (67 g), and 6 meatballs (31 g).

  
  

There is an important point to consider here. When physically active individuals try to meet their protein needs exclusively through whole foods, they may unintentionally consume excess fat and carbohydrates, and therefore excess calories. Over time, this can contribute to weight gain. Additionally, animal-based protein sources may increase saturated fat intake, while excessive reliance on plant-based proteins can lead to very high fiber intake, which may cause digestive or metabolic issues in some individuals. For this reason, controlled use of protein supplements can often be a practical and effective strategy for people who train regularly.

However, a healthy nutrition plan is not just about protein. Carbohydrate and fat intake must also be properly balanced, and micronutrients—vitamins and minerals—should not be neglected. Even if you cannot work regularly with a nutrition professional, seeking a few consultation sessions to establish a personalized foundation can make a meaningful difference in the long term.

Finally, let’s address a common question: “Does excess protein turn into fat?” Dietary protein is not stored as protein in the body. After digestion, it is broken down into amino acids, which are used for tissue repair and synthesis. Excess amino acids are not stored either; they are oxidized to produce energy. If the body does not require additional energy, the remaining energy can enter carbohydrate and fat metabolism through indirect metabolic pathways. The key factor is energy balance. If calorie intake consistently exceeds calorie expenditure, excess protein can indirectly contribute to fat gain over time.

Key takeaways:

• Optimal muscle development at any age requires adequate protein intake combined with resistance training.

• If you do not exercise, 0.8–1.2 g/kg of protein per day is sufficient.

• If you perform regular resistance training, intakes up to 1.6 g/kg may provide additional benefits; more than that is unnecessary.

• Excess protein does not directly convert to fat, but sustained energy surplus can ultimately lead to fat accumulation through metabolic processes.

Protein is not just about “how many grams.” The quality and source of protein matter just as much as quantity. To keep this article focused, differences in digestibility and bioavailability between protein sources will be discussed in a separate post.

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1. Nunes, E. A. Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults. Journal of Cachexia, Sarcopenia and Muscle. 2022.

2. Groenendijk, I. Discussion on protein recommendations for supporting muscle and bone health in older adults: A mini review. Frontiers in Nutrition. 2024.

3. Lamina, T. The effect of protein intake on health: A systematic review. Agency for Healthcare Research and Quality (US). 2024.

4. Maleky, F. Adhering to recommended dietary protein intake for optimizing human health benefits versus exceeding levels. RSC Advances. 2025.