Adequate protein intake is necessary for optimal health for a number of reasons. Dietary protein is used to repair and maintain bodily tissues and organs, support immune functions and promote muscle protein synthesis. This becomes a greater consideration among special populations who have distinct dietary needs, such as older adults. A new study published in the American Journal of Physiology – Endocrinology and Metabolism reflects this notion. The research team investigated the impact of varying amounts of daily protein intake, as well as timing, on net protein synthesis and muscle maintenance among older adults. Appropriate dietary modifications are important for older adults who usually suffer from a myriad of physiological declines; including their muscle-building efficiency. This loss in efficiency is directly associated with age-related sarcopenia (or loss of muscle mass), which can greatly reduce musculoskeletal functionality as well as the ability to remain independent. Maintaining greater muscle mass as we age can significantly contribute to an improved quality of life.
The current US recommendation for daily protein intake among the general population (non-athletes) is 0.8 g/kg of body weight. However, previous research has shown that older adults may need to consume more protein per meal in order to maximize protein synthesis throughout the day: which would equate to a significantly higher intake than the current recommended daily allowance (RDA) of 0.8 g/kg of body weight. In the current investigation, researchers at the Center for Translational Research in Aging and Longevity at the Donald W. Reynolds Institute on Aging at the University of Arkansas for Medical Sciences studied 20 healthy adults (52-75 years of age); randomly assigning them to one of four protein-intake groups over a four-day test period.
Breakdown of the four study groups:
All meals consumed by the subjects were prepared in the Metabolic Kitchen at University of Arkansas’ Translational Research Institute to ensure micronutrient accuracy. The team found that varying the distribution of protein across meals did not have a significant impact on increasing protein synthesis, but consuming 1.5 g/kg resulted in greater whole-body net protein balance and muscle synthesis. This finding supports previous research indicating that older adults should consume more protein to help thwart the effects of sarcopenia. Older clients experiencing age-related anabolic decline should be advised to consume adequate protein (perhaps slightly higher than what is generally recommended), from quality sources – and to couple this dietary measure with appropriate resistance training.