Sufficient protein intake is vital for a healthy diet. The recommended dietary allowance (RDA) has been estimated at 0.8 g of proteins per kg of body weight per day However, this should be seen as a minimum value to avoid deficiency and loss of lean body mass in young healthy adults and not as optimal for the entire population. Many if not most adults benefit from higher protein intake, while eating below 1.3 g/kg/d may lead to a loss of muscle mass. For this reason, higher intakes are often recommended to optimize specific health outcomes: increasing or maintaining lean body mass, enhancing health during ageing, inactivity, bed rest, or metabolic dysfunction, such as type 2 diabetes.
Claims that such higher intake levels may harm bone and kidney health are unfounded. Humans are evolutionarily adapted to elevated protein levels. Older adults and the elderly require intake levels of 1.0-1.5 g/kg/d for healthy ageing since this population has a greater need for protein than younger adults. Protein plays a beneficial role in the prevention of bone loss, in slowing down osteoporosis, and preventing sarcopenia, the loss of muscle mass. A protein intake above the current RDA may reduce hip fracture risk and play a beneficial role in Bone Mineral Density (BMD) maintenance and loss in older adults.
