9 Health Benefits of Protein

Protein is one of the three macronutrients found in food, and it plays a critical role in our health.

For this reason, it is essential to ensure we consume a sufficient amount of protein.

This article presents nine science-backed health benefits of consuming more protein.

1) Protein Promotes Satiety

There are three macronutrients in the human diet: carbohydrate, fat, and protein. Each of these macronutrients has its own characteristics, and each one can have a very different effect on our health.

Satiety, which can be defined as feeling full and not desiring to eat more food after a meal, is an important aspect to consider when planning a healthy diet. Most importantly, if we feel satiated, then we won’t have hunger cravings, snack, or overeat food.

Yes, calories do matter, but regulating total energy intake is much easier if we don’t feel the need to snack every few hours. And this is where protein comes in; scientific research suggests that it helps to promote satiety, and probably more so than other macronutrients (1, 2, 3, 4, 5).

In other words; protein might suppress hunger better than an equivalent amount of carbohydrate or fat.

Key Point: Protein helps us to feel fuller and less likely to experience food cravings.

2) Protein Helps To Build Muscle

Consuming enough dietary protein is essential for anyone who wishes to increase their muscle mass.

Although resistance training plays an essential part in building muscle, it will be difficult to make progress without a well-formulated nutrition plan.

This lack of focus on nutrition is one mistake that people can make; they work out hard, see a lack of results, and assume that they don’t have the right “genetics” to build muscle.

In truth, what you eat is just as important as what you lift.

There are a wealth of studies that back this up, and here is a summary of recent research:

  • Over a 4-week period, a randomized trial demonstrated that a protein intake of 2.4 grams per kilogram of body weight increased lean body mass more than 1.2 g per kg of body weight (6).
  • A systematic review assessed 49 studies involving 1863 participants, concluding that protein supplementation can significantly improve gains in strength and muscle size. However, when total protein intake was higher than 1.62 grams of protein per kilogram of body weight each day, no further gains were noted (7).
  • A systematic review evaluated data from 74 randomized controlled trials and found that protein supplementation slightly increased lean mass gains in resistance-trained individuals (8).

Key Point: Increasing protein intake is helpful for building muscle.

3) Sufficient Protein Promotes Healthy Hair and Skin

While many people know that protein helps us to build muscle, not as many realize it plays an integral role in our skin and hair health.

When we consume protein, it breaks down into the amino acids it contains, which are important building blocks for producing keratin (9).

Keratin is a type of protein that promotes strong and healthy hair and skin. In fact, keratin represents approximately 95% of the composition of human hair (10).

As a result, maintaining a sufficient protein intake is beneficial for promoting healthy hair, nails, and skin.

Key Point: An adequate protein intake is essential for healthy hair and skin.

4) Amino Acids Play a Significant Role In Immune Response

Ensuring a sufficient dietary protein intake can also have benefits for immune health.

Notably, protein enhances the human immune system, and specific amino acids, such as arginine, cysteine, and glutamine play a key role in immune response (9).

These, and other, amino acids also help to improve T-cell function (10, 11). T-cells are white blood cells that play a key role in the immune system by (12):

  • Attacking cells related to viruses and cancer cells
  • Coordinating immune responses
  • Helping to protect against re-infection to viruses

In contrast, a deficiency of dietary protein can impair the immune system and increase susceptibility to infectious disease (13).

Key Point: A sufficient intake of dietary protein is critical for optimal immune function.

5) Higher Protein Intake Protects Bone and Muscle Mass In the Elderly

Older adults often have the lowest protein intake. A 2019 analysis based on data from the National Health and Examination Survey found that up to 46% of adults aged 71 or over didn’t meet protein intake recommendations (14).

However, it is very important for older adults to get enough protein.

The reason for this is because, as we age, the rate of muscle protein synthesis (MPS) declines. This means that we absorb less protein from what we eat, which can lead to loss of lean body mass.

Sadly, skeletal muscle loss, frailty, and injuries often follow.

It may sound shocking, but by the time people hit their late 70s, it is common for them to have only 25% of the muscle mass they had during their prime years (15).

Despite this, we can protect against much of this muscle loss through our lifestyle habits.

For example, there are two main components involved in the regulation of MPS, and these are exercise—especially resistance training—and dietary protein intake.

Therefore, an exercise program combined with sufficient protein intake can help us to stay physically healthy as we age.

See here for a summary of the research on how much protein is “sufficient” for the elderly.

Further to this, insufficient dietary protein intake also raises the risk for osteoporosis and bone loss throughout adulthood (16).

Since protein plays a dual role in bone and muscle formation, ensuring an adequate intake can help to reduce the risk of age-related bone and muscle mass loss.

Key Point: Higher protein diets have some important advantages for the elderly.

6) Eating More Protein Can Support Weight Loss

Quick-fix crash diets may work for a short time, but they are unsustainable, and when people go back to their regular way of eating, the weight quickly comes back.

For long-term sustainable weight loss, it is vital that we find a diet we can enjoy and follow.

As discussed earlier, the evidence clearly shows that higher protein diets improve satiety.

If we feel satisfied with the food we eat, then that gives our chosen diet the biggest chance of success.

For these reasons, diets that emphasize a greater focus on protein often enjoy a higher adherence rate.

Studies on Higher Protein Intake and Weight Loss

Here are some (of many) recent high-quality studies that examined the potential of high-protein diets for weight loss;

  • A randomized clinical trial featuring 105 participants found that individuals on a high-protein diet lost more weight (7 kg) than those on a standard protein diet (5.1 kg) in a 6-month intervention. Additionally, the participants with the highest adherence rates to the high-protein diet lost “significantly more” weight (17).
  • A systematic review of twenty randomized controlled trials found that participants consuming higher protein diets lost more body fat while simultaneously retaining more lean mass (18).
Key Point: The data is comprehensive; higher protein diets are beneficial for losing weight.

7) Greater Protein Intake Can Improve Body Composition

A Man Drinking a Protein Supplement From a Workout Flask.

Based on the benefits discussed so far, this advantage of protein is fairly straightforward to understand.

Since protein can both assist with weight loss and promote muscle mass, higher protein diets can help to improve body composition.

For instance, a 12-month randomized clinical trial featuring 130 participants examined a high-protein diet versus a high-carbohydrate plan.

Despite calories being controlled, this study demonstrated that high-protein diets more effectively reduce body fat than high-carbohydrate diets. Additionally, this greater fat loss was especially significant in the more dangerous trunk region (19).

Extremely High Protein Intakes and Weight

Respected sports scientist Dr. Jose Antonio produced an interesting study that examined “over-consumption” of protein in resistance-trained individuals.

To summarize; the study investigated the effects of a hypercaloric diet featuring a protein intake equivalent to 5.5 times the recommended daily allowance.

Perhaps surprisingly, this extremely high protein intake led to no significant changes in fat mass or body fat percentage (20).

Key Point: Protein is advantageous for improving body composition.

8) Protein-Rich Foods Are Nutrient Dense

Think of almost pure sources of carbohydrate such as sugar and refined white flour; they contain virtually no nutritional value.

We can say the same for isolated dietary fats; sure, butter and olive oil contain some fat-soluble vitamins, but we can’t call them nutrient-dense.

On the other hand, foods with high protein-density tend to be very nutritious.

For example, chicken breasts and lean pork chops are two of the most protein-dense foods.

Although they are not the tastiest food in the world, chicken breasts are not just a source of protein, and they also supply significant amounts of B vitamins, phosphorus, and selenium (21).

It is the same for lean pork chops. Once again, this protein-dense meat is rich in B vitamins, and it also provides substantial amounts of phosphorus, selenium, and zinc (22).

In summary; increasing protein intake tends to increase nutrient intake too.

Key Point: Protein-rich foods are often nutrient-dense.

9) Protein Boosts Metabolism

Whenever we eat any food, the processes involved in digesting and processing that food increase the body’s metabolic rate (23).

We sometimes refer to this effect as either the ‘thermic effect’ (TEF) or ‘diet-induced thermogenesis’ (DIT).

In simple English, this means that we must expend energy after consuming a meal to process and absorb the nutrients.

Markedly, protein has a much higher thermic effect than either carbohydrate or fat.

While the thermic effect from dietary carbohydrate or fat maxes out at around 10%, researchers estimate the thermic effect of protein to be about 20-30% (2324).

To put it another way; consuming protein requires the use of energy equivalent to circa 25% of its calories to digest it.

As a result, consuming greater quantities of protein leads to a greater energy expenditure than lower protein diets.

Key Point: Protein has thermogenic advantages over other macronutrients.

Final Thoughts

As shown in this article, dietary protein can have many health benefits.

The amount of protein we all need will vary depending on personal circumstances, activity levels, age, and other such factors.

However, increasing protein at the expense of processed carbohydrates and isolated fats can improve the nutrient-density of the average diet.

For a healthy example of a high protein, lower carbohydrate diet, see this guide here.

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Michael Joseph, MSc

Michael works as a nutrition educator in a community setting and holds a Master's Degree in Clinical Nutrition. He believes in providing reliable and objective nutritional information to allow informed decisions.

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