TABLE 4.
Effect of whey protein supplementation on changes in physical function
| Groups/subgroups | Effect size (SMD) | 95% CI | No. of interventions/outcomes | I2 (%) | P-heterogeneity | P between-subgroup heterogeneity |
|---|---|---|---|---|---|---|
| All RCTs | 0.561 | 0.256, 0.865 | 33 | 90.69 | <0.001 | |
| RCT conducted on healthy older adults | 0.113 | −0.042, 0.268 | 17 | 30.22 | 0.115 | 0.000 |
| RCT conducted on sarcopenic/frail older adults | 1.211 | 0.588, 1.834 | 16 | 95.30 | <0.001 | |
| RCT measuring SPPB | 0.856 | −0.029, 1.741 | 7 | 94.55 | <0.001 | 0.135 |
| RCT measuring GS | 1.000 | 0.218, 1.782 | 9 | 92.48 | <0.001 | |
| RCT measuring other physical tests | 0.256 | −0.073, 0.585 | 17 | 86.62 | <0.001 | |
| RCT with RE | 0.055 | −0.066, 0.175 | 19 | 0.00 | 0.943 | 0.000 |
| RCT without RE | 1.551 | 0.834, 2.267 | 14 | 96.04 | <0.001 | |
| RCT with high dose of whey (>20 g/d) | 0.040 | −0.059, 0.140 | 26 | 0.00 | 0.502 | 0.000 |
| RCT with low dose of whey (<20 g/d) | 3.379 | 1.765, 4.994 | 7 | 97.96 | <0.001 | |
| RCT with high duration (>12 wk) | 1.042 | 0.503, 1.582 | 18 | 94.80 | <0.001 | 0.001 |
| RCT with low duration (≤12 wk) | 0.100 | −0.048, 0.248 | 15 | 10.19 | 0.339 |
Abbreviations: GS, gait speed; RCT, randomized controlled trial; RE, resistance exercise; SPPB, Short Physical Performance Battery; SMD, standardized mean difference.