EvidenceCLimitedStudies in people with real weaknesses: small, short or conflicting trials, or observational studies only.
Most healthy older adults do well on about 1.0 to 1.2 g of protein per kg of body weight a day, and 1.2 to 1.5 g if ill or active. That is above the standard 0.8 g.
Who it's for
Adults over 65, especially if active, ill or frail.
What to expect
Small gains in muscle and walking speed at 1.2 to 1.6 g/kg.
Watch out for
People with severe kidney disease may need to limit protein.
Muscle gain was largest at the highest protein dose
Bars show the average gain in muscle mass in each protein group of frail older adults.
Higher protein dose0.52
Lowest protein dose0.08
kg of muscle mass gained
Muscle gain was largest at the highest protein dose
The PROT-AGE Study Group advises people over 65 to average at least 1.0 to 1.2 g/kg a day, and at least 1.2 g/kg if they exercise or are active1Guideline · 2013Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study GroupMost older adults with acute or chronic disease need 1.2 to 1.5 g/kg a day. People with severe kidney disease (eGFR below 30) who are not on dialysis are the exception and may need to limit protein. Evidence was not yet sufficient for recommendations on protein quality or the timing of intake.PROT-AGE Study Group (European Union Geriatric Medicine Society). Most older adults with acute or chronic disease need 1.2 to 1.5 g/kg. People with severe kidney disease not on dialysis may need to limit protein1Guideline · 2013Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study GroupMost older adults with acute or chronic disease need 1.2 to 1.5 g/kg a day. People with severe kidney disease (eGFR below 30) who are not on dialysis are the exception and may need to limit protein. Evidence was not yet sufficient for recommendations on protein quality or the timing of intake.PROT-AGE Study Group (European Union Geriatric Medicine Society).
What the studies show
A trial of 120 frail or prefrail, undernourished adults aged 70 to 85 compared 0.8, 1.2 and 1.5 g/kg a day for 12 weeks. Only the 1.5 g group gained more muscle and walking speed than the 0.8 g group. The 1.2 g group did not differ from 0.8 g8Randomized trial · 2018 · 120 peopleProtein supplementation improves muscle mass and physical performance in undernourished prefrail and frail elderly subjects: a randomized, double-blind, placebo-controlled trial.The present study indicates that protein intake of 1.5 g · kg-1 · d-1 has the most beneficial effects in regard to preventing sarcopenia and frailty compared with protein intakes of 0.8 and 1.2 g · kg-1 · d-1 in prefrail or frail elderly subjects at risk of malnutrition. This trial was registered at cris.nih.go.kr as…Am J Clin Nutr.
A 10-week trial of 29 men over 70 compared 0.8 with 1.6 g/kg a day. The higher intake raised lean mass and leg power. The trial was small10Randomized trial · 2017 · 29 peopleThe effects of dietary protein intake on appendicular lean mass and muscle function in elderly men: a 10-wk randomized controlled trial.Consumption of a diet providing 2RDA for protein compared with the current guidelines was found to have beneficial effects on lean body mass and leg power in elderly men. These effects were not explained by differences in energy balance. This trial was registered at the Australia New Zealand Clinical Trial Registry…Am J Clin Nutr.
A review that pooled 74 trials in healthy adults found extra protein gave small muscle gains during weight training. In people 65 and older the gain appeared at 1.2 to 1.59 g/kg a day. Strength results were weaker and less certain2Meta-analysis · 2022Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults.There is a slight effect on bench press strength and minimal effect performance in physical function tests. The effect on handgrip strength is unclear.J Cachexia Sarcopenia Muscle.
A review of 49 trials (1,863 people) in healthy adults found gains in muscle leveled off above about 1.6 g/kg a day. Protein supplements worked less well with increasing age6Meta-analysis · 2018 · 1,863 peopleA systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6…Br J Sports Med.
A review of seven studies that followed or compared 3,353 older adults found those with age-related muscle loss ate less protein. These studies show a link only and can't show that low protein caused the loss3Meta-analysis · 2022Protein Intake and Sarcopenia in Older Adults: A Systematic Review and Meta-Analysis.Results of the present study suggest that an inadequate protein intake might be associated with sarcopenia in older adults.Int J Environ Res Public Health.
Many supplement trials added exercise, so the effect of protein alone is harder to separate. Most trials in muscle-loss reviews also had a high risk of bias4Meta-analysis · 2022 · 3,649 peopleManagement of Sarcopenia: A Network Meta-Analysis of Randomized Controlled Trials.Mixed exercise and physical activity with nutritional supplementation are the most effective sarcopenia interventions. Most of the included studies have a high risk of bias. More robust RCTs are needed to increase the confidence of our NMA results and the quality of evidence.J Am Med Dir Assoc,5Meta-analysis · 2021Nutritional interventions to improve muscle mass, muscle strength, and physical performance in older people: an umbrella review of systematic reviews and meta-analyses.Best evidence is available to recommend leucine, because it has a significant effect on muscle mass in elderly people with sarcopenia. Protein supplementation on top of resistance training is recommended to increase muscle mass and strength, in particular for obese persons and for ≥ 24 weeks. Effects on sarcopenia as…Nutr Rev.
Key studies
Study
Who
What it found
Position paper, 20131Guideline · 2013Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study GroupMost older adults with acute or chronic disease need 1.2 to 1.5 g/kg a day. People with severe kidney disease (eGFR below 30) who are not on dialysis are the exception and may need to limit protein. Evidence was not yet sufficient for recommendations on protein quality or the timing of intake.PROT-AGE Study Group (European Union Geriatric Medicine Society)
People over 65
At least 1.0 to 1.2 g/kg a day
Trial, 20188Randomized trial · 2018 · 120 peopleProtein supplementation improves muscle mass and physical performance in undernourished prefrail and frail elderly subjects: a randomized, double-blind, placebo-controlled trial.The present study indicates that protein intake of 1.5 g · kg-1 · d-1 has the most beneficial effects in regard to preventing sarcopenia and frailty compared with protein intakes of 0.8 and 1.2 g · kg-1 · d-1 in prefrail or frail elderly subjects at risk of malnutrition. This trial was registered at cris.nih.go.kr as…Am J Clin Nutr
120 frail adults, 70 to 85
1.5 g/kg beat 0.8 g/kg for muscle; 1.2 g/kg did not
Trial, 201710Randomized trial · 2017 · 29 peopleThe effects of dietary protein intake on appendicular lean mass and muscle function in elderly men: a 10-wk randomized controlled trial.Consumption of a diet providing 2RDA for protein compared with the current guidelines was found to have beneficial effects on lean body mass and leg power in elderly men. These effects were not explained by differences in energy balance. This trial was registered at the Australia New Zealand Clinical Trial Registry…Am J Clin Nutr
29 men over 70
1.6 g/kg beat 0.8 g/kg for lean mass and leg power
Review of 74 trials, 20222Meta-analysis · 2022Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults.There is a slight effect on bench press strength and minimal effect performance in physical function tests. The effect on handgrip strength is unclear.J Cachexia Sarcopenia Muscle
Healthy adults
Small muscle gains; older adults gained at 1.2 to 1.59 g/kg
Review of 49 trials, 20186Meta-analysis · 2018 · 1,863 peopleA systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6…Br J Sports Med
1,863 healthy adults
No added muscle gain above about 1.6 g/kg
Safety
People with severe kidney disease (eGFR below 30) not on dialysis may need to limit protein1Guideline · 2013Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study GroupMost older adults with acute or chronic disease need 1.2 to 1.5 g/kg a day. People with severe kidney disease (eGFR below 30) who are not on dialysis are the exception and may need to limit protein. Evidence was not yet sufficient for recommendations on protein quality or the timing of intake.PROT-AGE Study Group (European Union Geriatric Medicine Society). The frail-adult trial reported no harmful side effects at up to 1.5 g/kg a day8Randomized trial · 2018 · 120 peopleProtein supplementation improves muscle mass and physical performance in undernourished prefrail and frail elderly subjects: a randomized, double-blind, placebo-controlled trial.The present study indicates that protein intake of 1.5 g · kg-1 · d-1 has the most beneficial effects in regard to preventing sarcopenia and frailty compared with protein intakes of 0.8 and 1.2 g · kg-1 · d-1 in prefrail or frail elderly subjects at risk of malnutrition. This trial was registered at cris.nih.go.kr as…Am J Clin Nutr.
What we don't know
The best amount for healthy older adults who don't exercise, since many trials were in younger or healthy people or combined protein with exercise.
Whether protein type or timing across the day matters, which the guideline says lacks enough evidence1Guideline · 2013Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study GroupMost older adults with acute or chronic disease need 1.2 to 1.5 g/kg a day. People with severe kidney disease (eGFR below 30) who are not on dialysis are the exception and may need to limit protein. Evidence was not yet sufficient for recommendations on protein quality or the timing of intake.PROT-AGE Study Group (European Union Geriatric Medicine Society).
Written by AI from the studies listed, without review by a clinician, and graded with the GRADE method. It can be wrong, so check the studies it cites. Education, not medical advice.