Table 1 Study characteristics of the included studies
|
Author, year |
Study design, follow-up |
Sample size Gender |
Age (yr) BMI (kg/m2) LBM (kg) | Surgery type | Intervention | Pre-surgery protein intake (g/day) |
Actual protein intake (g/day) | Compliance | Protein intake analyzed | Outcomes analyzed | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| CON | PRO | ||||||||||
|
Clements et al., 2011 [24] |
Unblinded randomized control pilot study, 8 weeks |
30 M (n = 1) F (n = 29) |
46.0 ± 7.5 43.6 ± 4.2 54.0 ± 8.1 |
47.9 ± 9.6 42.9 ± 4.1 52.4 ± 6.9 | RYGB (n = 30) |
CON: usual care, no use of protein supplements PRO: oral supplement containing 24 g leucine metabolite, glutamine and arginine twice daily for 8 weeks | NA | NA | NA | Log sheets |
TBW, BMI Body composition using DXA (BFM, LBM) RMR |
|
Günes et al., 2019 [25] |
Randomized controlled trial, 6 months |
60 M (n = 9) F (n = 51) |
43.5 ± 8.4 45.9 ± 6.5 61.7 ± 13.3 |
40.3 ± 11.4 46.2 ± 5.0 47.5 ± 13.5 |
SG (n = 60) |
CON: standard diet for 1 month, no use of protein supplements PRO: standard diet + 1,2 g/kg IBW/day protein (±80 g) whey powder for 1 month | NA |
CON: NA PRO: 51 | 38%a | NA |
TBW, BMI Body composition using BIA (BFM, LBM) |
|
Oppert et al., 2018 [26] |
Randomized controlled trial, 6 months |
53 F (n = 53) |
43.9 ± 10,7 43.6 ± 6.2 55.6 ± 8.4 |
42.5 ± 8.7 43.3 ± 6.0 55.9 ± 6.1 | RYGB (n = 53) |
CON: usual care with general dietary and physical activity counselling PRO: oral supplement containing whey-protein-enriched powder (24 g) twice daily for 6 months |
CON: 80 PRO: 82 |
CON: 60 PRO: 82 | 55% | Dietary history method. Return of empty cans of protein powder |
TBW, BMI Body composition using DXA (BFM, LBM) |
|
Schiavo et al., 2017 [27] |
Randomized comparative study, 12 months |
60 M (n = 60) |
41.0 ± 6.2 40.7 ± 5.3 75.0 ± 11.9 |
43.0 ± 5.5 42.1 ± 6.2 76.3 ± 7.0 |
SG (n = 60) |
NPD (normal protein diet): 1.0 g/kg IBW/day protein (23.3%), 15% fat and 61.7% carbohydrates for 12 months PED (protein-enriched diet): 2.0 g/kg ideal IBW/day protein (±160 g)(47.7%), 15% fat and 37.7% carbohydrates for 12 months | NA |
CON: 67 PRO: 143 | Very high | Questionnaires, 3 day dietary record, 72 h-recall |
TBW, BMI Body composition using BIA (BFM, LBM) RMR |
| Schollenberger et al., 2016 [28] |
Randomized controlled double-blind pilot study, 6 months |
20 M (n = 3) F (n = 17) |
47.0 ± 11.9 49.0 ± 5.1 68.9 ± 13.4 |
43.4 ± 13.3 52.0 ± 7.6 65.2 ± 14.2 |
RYGB (n = 5) SG (n = 15) |
CON: pure maltodextrin powder, 15 g/day first month, 30–35 g/day second-sixth month PRO: milk protein powder, 15 g/day first month, 30–35 g/day second-sixth month |
CON: 93 PRO: 97 |
CON: 53 PRO: 67 | 86% | 4 day dietary record, interviews |
TBW, BMI Body composition using BIA (BFM, LBM) |