The recommended dietary allowance (RDA) for protein intake varies by age, sex, and activity level. Generally, it is suggested that adults consume about 0.8 grams of protein per kilogram of body weight. For those engaged in regular exercise or muscle building, higher protein amounts, often between 1.2 to 2.0 grams per kilogram, may be beneficial. Adequate protein supports muscle repair and growth, immune function, and overall health, emphasizing its importance in a well-rounded diet.