Why do we need protein
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The Importance of Protein in Human Nutrition
Protein and Muscle Maintenance
Proteins are essential macronutrients that play a critical role in maintaining and building muscle mass. For athletes, protein intake is particularly important as it supports muscle protein synthesis, which is crucial for muscle growth and repair. Studies indicate that athletes, especially those engaged in resistance training, may benefit from higher protein intakes to maximize muscle protein synthesis and support muscle hypertrophy 12. The recommended protein intake for athletes can range from 1.3 to 2.0 grams per kilogram of body weight per day, depending on the intensity and frequency of their training 2.
Protein and Overall Health
Beyond muscle maintenance, proteins are vital for overall health. They are composed of amino acids, which are necessary for various bodily functions, including the synthesis of enzymes, hormones, and other essential molecules. Adequate protein intake is crucial for preventing conditions such as stunting, anemia, physical weakness, and impaired immunity 3. The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day for healthy adults with minimal physical activity, but this requirement increases with higher levels of physical activity 3.
Protein for Older Adults
Older adults have increased protein needs to support good health, promote recovery from illness, and maintain functionality. Age-related changes in protein metabolism, such as reduced anabolic responses and increased protein requirements due to chronic diseases, necessitate higher protein intake. Recommendations for older adults suggest a daily intake of 1.0 to 1.2 grams per kilogram of body weight, with even higher intakes for those who are active or have acute or chronic diseases 7.
Protein Quality and Sources
The quality of protein is determined by its amino acid profile and digestibility. Animal proteins are generally considered high-quality because they contain all essential amino acids in the right proportions. However, plant proteins can also be a valuable source of nutrition, especially when combined to provide a complete amino acid profile 69. Blends of different protein sources, such as dairy and soy, are increasingly used in sports nutrition products to leverage the benefits of both animal and plant proteins 8.
Conclusion
Protein is indispensable for maintaining muscle mass, supporting overall health, and meeting the increased nutritional needs of specific populations such as athletes and older adults. While animal proteins are traditionally seen as high-quality sources, plant proteins can also meet human nutritional requirements when appropriately combined. Ensuring adequate protein intake from diverse sources is essential for optimal health and functionality.
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Most relevant research papers on this topic
Protein and amino acids for athletes
Athletes can maintain lean body mass within a wide range of protein intakes, with higher intakes potentially beneficial for muscle hypertrophy.
Highly CitedDietary protein for athletes: From requirements to optimum adaptation
Athletes aiming to gain muscle mass and strength should consume 1.3-1.8 g kg 1 day1 of dietary protein, with leucine and other branched-chain amino acids playing a key role in muscle protein synthesis.
Highly CitedDietary protein intake and human health.
Adequate consumption of high-quality proteins from animal products is essential for optimal growth, development, and health in adults.
Highly CitedProtein—Not Just a Food Group!
Proteins are the workers inside our cells, and they play a crucial role in maintaining our health and growth.
Proteins in Pulses
Pulses, such as lentils, chickpeas, and peas, contain essential amino acids and are a good source of protein for maintaining health.
Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group.
Older adults need 1.0 to 1.2 g protein per kilogram of body weight per day to maintain lean body mass and function, with higher protein intake for those exercising and active.
Highly CitedThe Rationale for Consuming Protein Blends in Sports Nutrition
Whey protein, casein, and isolated soy protein blends in sports nutrition products offer potential nutritional advantages over individual protein sources, improving overall health and performance.
Plant proteins as high-quality nutritional source for human diet
Plant proteins offer a diverse, high-quality nutritional source for human diet, with potential for reducing animal protein dependence and meeting environmental and social needs.
Highly CitedProteins from land plants – Potential resources for human nutrition and food security
Plant proteins can provide sufficient essential amino acids for human health and reduce environmental strain, offering a sustainable alternative to animal proteins in human diets.
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