The Importance of Animal Proteins for Human Nutrition

Proteins, essential compounds containing carbon, hydrogen, oxygen, and nitrogen, are synthesized through peptide bonds between amino acids. Recognized in the 18th century, proteins’ significance in nutrition and biology was established by early hypotheses from scientists like Gerhardus Johannes Mulder and Berzelius. Proteins consist of 20 amino acids, categorized into essential and non-essential. Non-essential amino acids, such as glutamine, glycine, and cysteine, are synthesized by the body and support crucial functions like cell growth and metabolism. Essential amino acids, including phenylalanine, threonine, and branched-chain amino acids (BCAAs), must be obtained from the diet and are vital for protein synthesis. BCAAs are significant in muscle metabolism and have shown health benefits in studies, including muscle mass preservation and mental health improvement. Projected global population growth to 9.7 billion by 2050 emphasizes the need for diverse protein sources. High-quality animal proteins, like those from eggs, meat, milk, and fish, are efficiently converted into body proteins. Plant proteins, though slightly less digestible, remain essential for sustainable nutrition. Protein quality is assessed using methods like the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) and the newer Digestible Indispensable Amino Acid Score (DIAAS). Despite DIAAS being more accurate, PDCAAS is still widely used due to data limitations. Surveys in Türkiye show higher protein intake in males compared to females. The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg of body weight, with variations across age and gender. Ensuring adequate protein intake is critical for health, as shown by varying nutritional statuses, especially in older populations, underscoring the importance of diverse protein sources.