Protein Requirements and Recommendations for Older People: A Review

Abstract

Declines in skeletal muscle mass and strength are major contributors to increased mortality, morbidity and reduced quality of life in older people. Recommended Dietary Allowances/Intakes have failed to adequately consider the protein requirements of the elderly with respect to function. The aim of this paper was to review definitions of optimal protein status and the evidence base for optimal dietary protein. Current recommended protein intakes for older people do not account for the compensatory loss of muscle mass that occurs on lower protein intakes. Older people have lower rates of protein synthesis and whole-body proteolysis in response to an anabolic stimulus (food or resistance exercise). Recommendations for the level of adequate dietary intake of protein for older people should be informed by evidence derived from functional outcomes. Randomized controlled trials report a clear benefit of increased dietary protein on lean mass gain and leg strength, particularly when combined with resistance exercise. There is good consistent evidence (level III-2 to IV) that consumption of 1.0 to 1.3 g/kg/day dietary protein combined with twice-weekly progressive resistance exercise reduces age-related muscle mass loss. Older people appear to require 1.0 to 1.3 g/kg/day dietary protein to optimize physical function, particularly whilst undertaking resistance exercise recommendations.

Whole-body electromyostimulation to fight sarcopenic obesity in community-dwelling older women at risk. Resultsof the randomized controlled FORMOsA-sarcopenic obesity study

“…One explanation may be that in line with data from neighboring countries [35], baseline protein intake of all groups was already sufficiently high; just one of the participants fell below the general protein intake recommendation (RDA) of 0.8 g/kg body mass/day [36,37] ( Table 2). In fact, the majority of the participants (63 %) consumed more than 1.0 g/kg/day, which is the lower limit of recent recommendations for healthy older people [38,39]. In the case of exercise, the ACSM and ADA recommend 1.2-1.7 g/kg/day [40] in order to support the increased protein metabolism during and after exercise.…”

Osteosarcopenic obesity in women: impact, prevalence, and management challenges

“…However, nitrogen balance studies suggest that older adults need to consume a higher amount of protein (1.4–1.6 g/kg/d) 71–73. In a recently published review, protein intake of 1.0–1.3 g/kg/d has been recommended to reduce muscle loss in elderly populations 74. Inadequate protein intake in aging adults combined with physical inactivity may further exacerbate the decline in muscle protein synthesis associated with aging.…”

Regulation of metabolic health and aging by nutrient-sensitive signaling pathways

“…However, CR or protein restriction in the elderly will need to be approached cautiously; the preservation of muscle and bone mass is a priority in the aged, as sarcopenia is a major driver of frailty and loss of independence (Jensen et al, 2014; Landi et al, 2015). Indeed, a growing body of research suggests that protein intake by the elderly may need to be increased in order to preserve muscle mass (Nowson and O’Connell, 2015; Paddon-Jones and Rasmussen, 2009; Wolfe et al, 2008), and low protein diets may not decrease mortality in people over the age of 65 (Levine et al, 2014). However, lifelong CR diet feeding preserves muscle mass in rodents and non-human primates despite an absolute reduction in protein intake (Aspnes et al, 1997; Colman et al, 2008; McKiernan et al, 2012; Mercken et al, 2012; van Norren et al, 2015), suggesting that these types of interventions may reduce the need to increase protein intake during aging.…”