TABLE 2.
Effect of whey protein supplementation on changes in LM
| Groups/subgroups | Effect size (SMD) | 95% CI | No. of interventions/outcomes | I2 (%) | P-heterogeneity | P between-subgroup heterogeneity |
|---|---|---|---|---|---|---|
| All RCTs | 0.165 | −0.154, 0.484 | 31 | 90.30 | <0.001 | |
| RCT conducted on healthy older adults | -0.238 | −0.511, 0.034 | 20 | 80.04 | <0.001 | 0.321 |
| RCT conducted on sarcopenic/frail older adultsis | 0.982 | 0.228, 1.736 | 11 | 94.36 | <0.001 | |
| RCT measuring TLM | -0.038 | −0.528, 0.452 | 16 | 92.02 | <0.001 | 0.206 |
| RCT measuring ALM | 0.374 | −0.036, 0.784 | 15 | 87.36 | <0.001 | |
| RCT with RE | 0.165 | −0.154, 0.484 | 19 | 0.00 | 0.650 | 0.193 |
| RCT without RE | 0.536 | −0.266, 1.338 | 12 | 96.26 | <0.001 | |
| RCT with high dose of whey (>20 g/d) | 0.001 | −0.126, 0.127 | 21 | 0.00 | 0.671 | 0.174 |
| RCT with low dose of whey (<20 g/d) | 0.619 | −0.265, 1.502 | 10 | 96.92 | <0.001 | |
| RCT with high duration (>12 wk) | 0.463 | −0.240, 1.167 | 13 | 95.94 | <0.001 | 0.210 |
| RCT with low duration (≤12 wk) | 0.005 | −0.131, 0.140 | 18 | 0.00 | 0.712 |
Abbreviations: ALM, appendicular lean mass; RCT, randomized controlled trial; RE, resistance exercise; SMD, standardized mean difference; TLM, total lean mass.