Dietary supplement
According to US & Canadian Dietary Reference Intake guidelines, the protein Recommended Dietary Allowance (RDA) for adults is based on 0.8 grams protein per kilogram body weight. The recommendation is for sedentary and lightly active people. Scientific reviews can conclude that a high protein diet, when combined with exercise, will increase muscle mass and strength, or conclude the opposite. The International Olympic Committee recommends protein intake targets for both strength and endurance athletes at about 1.2-1.8 g/kg body mass per day. One review proposed a maximum daily protein intake of approximately 25% of energy requirements, i.e., approximately 2.0 to 2.5 g/kg.
Human genome
Recently, a systematic meta-analysis of updated data of the human genome found that the largest protein-coding gene in the human reference genome is "RBFOX1" (RNA binding protein, fox-1 homolog 1), spanning a total of 2.47 MB. Over the whole genome, considering a curated set of protein-coding genes, the median size of an exon is currently estimated to be 133 bp (mean = 309 bp), the median number of exons is currently estimated to be 8 (mean = 11), and the median coding sequence is currently estimated to encode 425 amino acids (mean = 553 amino acids; Tables 2 and 5 in).