Human nutrition
The protein requirement for each individual differs, as do opinions about whether and to what extent physically active people require more protein. The 2005 Recommended Dietary Allowances (RDA), aimed at the general healthy adult population, provide for an intake of 0.8 grams of protein per kilogram of body weight. A review panel stating that "no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise."
Puppy nutrition
Growing puppies require higher levels of protein than adult dogs of the same breed to promote proper growth and development. Protein should account for at least 25% of energy; however protein requirements also depend on the digestibility of the protein and age of the puppy. Amino acid and nitrogen requirements decrease between 10–14 weeks, indicating that different protein levels are often beneficial before and after 14 weeks of age. Before 14 weeks of age, a protein level of 250 g/kg of diet (25% of the diet) containing 4.0 kcal ME/g will result in optimal growth. After 14 weeks of age, protein requirements decrease to 200 g/kg of diet (20% of the diet) for optimal growth.