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.
Puppy nutrition
Protein in excess of these levels is metabolized and leads to an increase of the glomerular filtration rate, and increased urea excretion in the urine, with no evidence of damage to the kidneys. However, addition of protein past these requirements is not recommended, although the NRC has not quantified a safe upper limit. Considering that the energy density of protein is similar to that of carbohydrates, an excess of protein in the diet may lead to fat deposition and weight gain. This excess weight can lead to abnormal joint development, potentially giving rise to joint issues in the future. Additionally, excess of some amino acids may also have detrimental impacts; for example, excess lysine will negatively antagonise arginine. The minimal requirement laid out by the NRC is 180g/kg (18%) DM of crude protein, with a recommended allowance of 225g/kg (22.5%) DM. With this in mind, it is also important to consider the quality and digestibility of the protein used.