Table 2.
Associations of dietary source of protein with measures of muscle in epidemiological studies.
| Study Design | Population, n | Exposure or Intervention | Outcome Measures | Results | References |
|---|---|---|---|---|---|
| Cross-sectional | Men and women; mean age 59; n = 2675 | Total, animal, plant protein intake; FFQ | Leg lean mass, isometric quadriceps strength | Total and animal protein positively associated with lean mass; Higher quadriceps strength in higher quartiles compared to lowest quartile of plant protein intake | [107] |
| Longitudinal (6 years) |
Men and women; mean age 59; n = 5124 | Total, animal and plant protein intake; FFQ | Grip strength, arm lean mass | Total and animal protein intake were protective against loss of grip strength | [108] |
| Longitudinal (3 year) |
Men and women; mean age 40; n = 2986 | Total protein intake, cluster analysis; FFQ | Appendicular lean mass, quadriceps strength | Total protein intake associated with appendicular lean mass and quadriceps strength | [109] |
| Longitudinal (4 years) |
Men and women; mean age 72; n = 3122 | Net Endogenous Acid Production from Diet; FFQ | Appendicular lean mass | Lower acid load (more plant protein) associated with slower decline in muscle mass | [110] |
| Longitudinal (4 years) |
Men and women; mean age 72; n = 2726 | Total, animal, plant protein intake; FFQ | Appendicular lean mass | Plant protein intake protective against loss of appendicular lean mass but not total or animal protein | [111] |
| Longitudinal (2.6 ± 0.4 years) |
Female; mean age 62; n = 740 | Total protein intake; FFQ | Appendicular lean mass, knee extensor strength | Failing to meet the recommended consumption of protein associated with significantly lower ALM, but not muscle strength | [76] |
| Longitudinal (5 year) |
Men and women; mean age 74; n = 1561 | Total, animal, plant protein intake; FFQ | Total lean mass, appendicular lean mass | Total and animal protein intake is associated with preservation of lean body mass | [77] |
| Longitudinal (3 year) |
Women; mean age 68; n = 552 | Baseline total protein intake; 3-day food record | Physical performance measures | Higher consumption of dietary protein is associated with better physical function and muscle strength | [75] |
FFQ, Food Frequency Questionnaire; ALM, Appendicular Lean Mass.