Determining the right amount of protein for your health and lifestyle

Protein plays a crucial role in maintaining and promoting overall health, often called the building blocks of life. From conception until our final breath, proteins are involved in nearly every biological process within our bodies. However, determining the right amount of protein for an individual’s unique needs can be challenging, influenced by various factors such as age, gender, chronic health conditions, exercise routine, and personal health goals.

In this article, we’ll explore protein’s importance in health, highlighting how protein needs vary depending on factors such as bariatric surgery, renal disease, diabetes, insulin resistance, kidney stones, gout, muscle loss, workout routines, appetites, genders, and ages. Moreover, we will examine key laboratory indicators used to assess a person’s protein status and the impact of protein timing on exercise.

First, let’s discuss what protein is and why it’s important before discussing how much protein we need.

Why is protein important, and what are its benefits?

Protein is one of the three essential macronutrients, along with carbohydrates and fats. Human bodies need these nutrients in relatively large quantities to function properly.

Proteins are the body’s main building blocks, made up of amino acids. Among the twenty amino acids, nine are essential, meaning the body cannot produce them and must obtain them through diet. 

There are different amino acid compositions in different protein sources. Plant-based diets are less likely to contain all the ‘essential’ amino acids than lean meats and dairy products. However, getting all the essential protein elements on a plant-based diet is perfectly possible with just a little research and nutritional consideration. 

The Health Benefits of Protein

• Building and Repairing Tissues

Muscles, organs, and tissues are made up of proteins. These proteins are crucial for constructing new tissues, ensuring proper organ formation, and supporting healthy cell division as we grow and develop. Additionally, proteins facilitate the repair of damaged tissues, aiding recovery after injuries or illnesses. Insufficient protein intake can result in delayed healing and compromised health.

Moreover, muscle tissue, made up of protein, plays an important role in metabolism, particularly in glucose and fat metabolism. In our previous post titled “Why Should You Care More About Muscle Than Body Fat?”, maintaining muscle mass was emphasized for its positive impact on long-term health and weight management.

Maintaining muscle mass is especially critical during weight loss and post-bariatric surgery, as rapid weight loss can lead to muscle loss. Protein consumption is essential during this time to promote muscle recovery and growth.

• Enzyme Function and Metabolic Reactions

Biological catalysts, like enzymes, facilitate chemical reactions within our bodies, making them essential to metabolism and various physiological processes. These enzymes are, in fact, specialized proteins that accelerate reactions that would otherwise occur too slowly to sustain life. 

Enzymes are crucial to metabolism, which converts food into energy and building blocks. In this way, proteins contribute to our body’s ability to process nutrients, synthesize molecules, and maintain proper hormonal balance.

• Immune System Support

A robust immune system is essential for defending the body against harmful pathogens and foreign invaders. The immune system is also strengthened by proteins, which produce antibodies, which are specialized proteins that neutralize specific antigens (foreign substances). These antibodies help identify and neutralize harmful bacteria, viruses, and other pathogens, thus protecting us from various infections and diseases.

• Transport of Substances

Proteins are responsible for transporting vital substances throughout the body. Hemoglobin, for instance, transports oxygen from the lungs to various tissues and organs through red blood cells. 

Moreover, proteins in cell membranes serve as transporters, enabling nutrients, ions, and other molecules to enter and exit cells. These transport proteins ensure that essential nutrients reach cells, preventing adverse health effects.

• Hormonal Regulation

A hormone is a chemical messenger that regulates physiological processes and communicates between organs and systems. Hormones are often proteins or molecules that look like proteins. 

For example, insulin controls blood sugar levels, a protein hormone produced in the pancreas. The synthesis and function of hormones such as growth, thyroid-stimulating, and insulin-like growth factors rely on proteins. Proper hormonal regulation is vital for maintaining a stable internal environment and overall health.

• Maintaining Fluid Balance

Proteins are essential for maintaining the body’s fluid balance. Albumin, a protein found in the blood, prevents tissues from accumulating excess fluid. This promotes proper circulation and prevents edema (fluid retention) within blood vessels. Protein deficiency can result in fluid imbalances, resulting in swelling, decreased blood volume, and cardiovascular problems.

• Source of Energy

A protein can also provide energy when carbohydrates and fats are insufficient. When you fast for a long period of time, starve for a long period of time, or exercise vigorously, your body may convert proteins into glucose through a process called gluconeogenesis. 

However, relying on protein for energy can lead to muscle wasting and other health complications, underscoring the importance of maintaining adequate carbohydrate and fat intake to spare proteins for their vital functions.

Protein Requirements

Various factors determine how much protein an individual needs, including age, sex, weight, level of physical activity, and overall health. The Recommended Dietary Allowance (RDA) for sedentary adults is 0.8% protein in every kilogram of body weight. However, this may only be suitable for some.

Physically active individuals and athletes may require more protein to support muscle growth and repair. Based on recommendations from the International Society of Sports Nutrition, athletes should consume 1.4-2.0 grams of protein per kilogram of body weight. In addition, older adults may need more protein to prevent muscle loss.

Individual Protein Needs: Factors Influencing Protein Requirements

Several factors can influence an individual’s optimal protein intake. Let’s explore how specific health conditions, lifestyle choices, and biological factors impact protein requirements in this section.

• Bariatric Surgery and Other Surgical Procedures

A study published in 2020 investigated the impact of protein intake on weight loss and muscle mass after bariatric surgery. Researchers found that consuming more protein helped preserve muscle and promote weight loss.

 In the aftermath of surgery, protein becomes crucial for facilitating healing and preserving muscle mass. It is, therefore, common for individuals who have undergone bariatric surgery or other surgical procedures to require a modified protein intake. 

The American Society for Metabolic and Bariatric Surgery recommends 60-80 grams of protein daily following bariatric surgery. Alternatively, some people may need more protein and require more than 100 grams.  

However, it is essential to recognize that each person’s needs may vary based on factors such as body composition, physical activity, and underlying health conditions. The Registered Dietitian can help you personalize this number based on your needs. 

• Renal Disease and Protein Intake

Individuals with renal disease or compromised kidney function should carefully manage protein intake. Consuming excessive protein can increase blood urea nitrogen (BUN), which may put additional strain on the kidneys and exacerbate the condition. In such cases, personalized protein recommendations from a registered dietitian are essential, considering the severity of the kidney disease and other individual health factors.

A study published in Nutritional Management of Renal Disease, 2022, examined protein intake in patients with chronic kidney disease. Researchers found that a controlled protein intake, tailored to a patient’s needs, improved renal function and overall health.

• Diabetes and Insulin Resistance

Individuals with diabetes or insulin resistance must be mindful of their protein intake to avoid potential complications. It is possible to develop kidney stones, gout, and other kidney diseases if you consume too much protein. In such cases, opting for more plant-based protein sources can be beneficial.

Some studies have found that consuming more protein may help to improve blood sugar control, while others have found that it may have the opposite effect.

• Muscle Loss and Sarcopenia

Muscle loss, also known as sarcopenia, can occur due to various factors, such as rapid weight loss or aging. As a result, increasing protein intake becomes crucial for muscle repair and growth.

A study published in the American Journal of Medicine (2022) found that older adults who consumed 1.2-1.5 grams protein per kilogram of body weight had a lower risk of sarcopenia. This means that a 70-kilogram (154-pound) older adult would need to consume 84-105 grams of protein per day.

• Workout Routine and Protein Requirements

Intensity, frequency, and type of workouts all influence protein needs. Those who engage in regular, intense exercise, especially resistance training, need more protein to recover and build muscle.

In a study, athletes who consumed 2.0-2.4 grams protein per kg of body weight gained more muscle mass after resistance training. Thus, a 70-kilogram (154-pound) athlete needs 140-168 grams of protein daily.

Additionally, a Sports Medicine (2018) meta-analysis examined how protein supplementation affects muscle strength and size in resistance-trained individuals. The researchers found that protein supplementation significantly enhanced muscle hypertrophy and strength gains compared to a placebo.

• Current Health Goals and Protein Intake

Protein intake may need to be adjusted according to specific health goals, such as weight loss or muscle growth. High-protein diets can aid in appetite control and contribute to muscle development, but the amount should be tailored to individual needs.

A Nutrition and Metabolism (2020) study examined how high-protein diets affect body composition and appetite in overweight and obese individuals. According to the study, a high-protein diet promoted greater fat loss, improved body composition, and reduced hunger.

• Appetite and Hunger Needs

Protein requirements are also influenced by appetite and hunger. Higher appetites may naturally consume more protein, while others may need nutritional guidance.

A study in the Journal of the American Medical Association found that individuals with higher hunger scores were more likely to consume more protein. The study also found that people who consumed more protein were likely to have a lower body mass index and lower chances of developing chronic diseases.

Another study found that people who consumed more protein were more likely to feel full after meals. The study also found that people who felt fuller after meals were less likely to snack between meals.

• Gender and Age

Gender and age are essential factors influencing protein needs. Women, in particular, may have unique protein requirements, especially after strenuous workouts. Consuming 30-40 grams of protein within 30-45 minutes of vigorous exercise can help prevent cortisol spikes, which could otherwise hinder muscle recovery.

A study published in the Journal of the International Society of Sports Nutrition (2023) investigated gender differences in post-exercise protein intake and muscle protein synthesis. The researchers reported that women experienced higher muscle protein synthesis rates when consuming protein after exercise, highlighting the importance of protein timing for optimal recovery.

Protein Timing and Exercise

Exercise timing is also important for optimizing muscle recovery and growth. Consuming protein shortly after a workout can enhance muscle protein synthesis and repair. 

A study in the International Society of Sports Nutrition found that athletes who consumed 30 grams of protein within 30 minutes of resistance training significantly increased muscle mass more than those who did not consume protein after exercise.

Laboratory Indicators of Protein Status

Assessing an individual’s protein status is essential for guiding dietary recommendations. Several laboratory indicators can provide useful information about protein intake and metabolism. Here are some common laboratory indicators used to assess protein status:

• Albumin: 

In the blood, serum albumin serves as a marker of protein status for a long time. Albumin has a half-life of 30-40 days, indicating protein intake over the past month. A low level of albumin may indicate malnutrition or chronic protein deficiency.

• Prealbumin  (Transthyretin): 

Prealbumin is a protein that has a shorter half-life than albumin. The half-life of prealbumin is only 3-4 days, giving insight into recent protein intake. Short-term changes in protein intake can be tracked using this marker. 

• Blood Urea Nitrogen (BUN): 

Blood nitrogen content (BUN) is determined by protein breakdown in the body. High BUN levels may indicate excessive protein intake, while low levels could signal insufficient protein consumption.

• Serum Total Protein: 

All proteins in the blood are measured in serum total protein, including albumin and globulin. It provides a general overview of an individual’s protein status.

• Serum Creatinine: 

Muscle metabolism generates creatinine as a waste product. This can be used to determine muscle mass and, subsequently, protein status. Low creatinine levels may suggest muscle wasting due to inadequate protein intake.

• Urinary Urea Nitrogen (UUN): 

The UUN measures how much nitrogen the body excretes in its urine, which reflects how much protein it catabolizes. A high UUN level may indicate excessive protein breakdown or excessive protein consumption.

• Nitrogen Balance: 

In nitrogen balance, nitrogen intake (from protein) is compared with nitrogen excretion (through urine, feces, and sweat). A positive nitrogen balance indicates a surplus of protein intake, while a negative nitrogen balance indicates insufficient protein intake.

• Serum Transferrin: 

The transferrin protein is responsible for transporting iron throughout the body. Protein status can affect its levels, and low levels may indicate malnutrition.

• Insulin-Like Growth Factor 1 (IGF-1): 

IGF-1 is influenced by protein intake and is involved in muscle growth and repair. A low level of IGF-1 may indicate a protein deficiency.

• C-reactive protein (CRP): 

CRP is an inflammatory marker that is elevated in response to infection or inflammation. Inflammatory conditions can affect protein metabolism and status.

Conclusion

Protein is vital in many physiological processes that support overall health and well-being in a well-balanced diet. It is important to consider your medical conditions, age, gender, exercise routine, and personal objectives when determining how much protein you should consume.

When you consume the right amount of protein in your diet, tailored to your needs, you will maintain muscle health and contribute to your overall vitality and longevity. Working with a Registered Dietitian or healthcare professional can help individuals achieve their wellness goals.