Table 2.
Key study features and participant characteristics of studies included in this systematic review.
| Study Characteristic | Mean (Range)—Unless Indicated Otherwise | ||
|---|---|---|---|
| Protein vs. digestible CHO | |||
| Number of studies | 35 | ||
| Number of participants | 113 (12–773) | ||
| Male/Female | 30 (0–168)/63 (0–300) | ||
| Age | 46 (22–62) * | ||
| BMI | 33.9 (29.9–45.6) * | ||
| Diet characteristics | |||
| Protein | |||
| HP | 30 (20–59) E% | ||
| SP | 15 (2–20) E% | ||
| Fat | |||
| HP | 28 (5–30) E% | ||
| SP | 28 (3–30) E% | ||
| CHO | |||
| HP | 41 (25–48) E% | ||
| SP | 57 (50–95) E% | ||
| Number of studies evaluating effects on | |||
| Weight loss | 18 | ||
| Weight loss maintenance | 11 | ||
| Weight maintenance | 6 | ||
| Protein vs. fiber | |||
| Number of studies | 2 | ||
| Number of participants | 104 (83–125) | ||
| Male/Female | 30 (0–59)/75 (66–83) | ||
| Age | 41 (40–42) * | ||
| BMI | 32.3 (31.5–34.0) * | ||
| Diet characteristics | See Supplementary Material Table S1 | ||
| Number of studies evaluating effects on | |||
| Weight loss | 0 | ||
| Weight loss maintenance | 1 | ||
| Weight maintenance | 1 | ||
| Protein vs. fat | |||
| Number of studies | 2 | ||
| Number of participants | 75 (57–93) | ||
| Male/Female | 13 (0–25)/63 (32–93) | ||
| Age | 50 (mean only reported in one of the studies) | ||
| BMI | 34.9 (34.0–35.7) * | ||
| Diet characteristics | |||
| Protein | |||
| HP | 35 (30–40) E% | ||
| HF | 20 (20) E% | ||
| Fat | |||
| HP | 30 (30) E% | ||
| HF | 45 (40–50) E% | ||
| CHO | |||
| HP | 35 (30–40) E% | ||
| HF | 35 (30–40) E% | ||
| Number of studies evaluating effects on | |||
| Weight loss | 1 | ||
| Weight loss maintenance | 1 | ||
| Weight maintenance | 0 | ||
| Protein supplementation vs. no supplementation (no placebo used) | |||
| Number of studies | 2 | ||
| Number of participants | 134 (120–148) | ||
| Male/Female | NR | ||
| Age | 44 (mean only reported in one of the studies) | ||
| BMI | 29.5 (29.4–29.5) * | ||
| Diet characteristics | |||
| Amount of protein supplementation | 39.1 (30.0–48.2) g/d | ||
| Protein intake | |||
| I | 18 (18) E% | ||
| C | 15 (15) E% | ||
| Number of studies evaluating effects on | |||
| Weight loss | 0 | ||
| Weight loss maintenance | 2 | ||
| Weight maintenance | 0 | ||
| Different proteins—studies only included in separate meta-analysis | |||
| Number of studies | 6 | ||
| Number of participants | 76 (18–131) | ||
| Male/Female | 26 (0–68)/50 (15–95) | ||
| Age | 45 (26–51) * | ||
| BMI | 31. 4 (28.3–34.4) * | ||
| Diet characteristics | Number of studies | ||
| Whey protein | 3 | ||
| Lupin | 1 | ||
| Animal vs. vegetable protein | 1 | ||
| Specific peptide | 1 | ||
| Number of studies evaluating effects on | |||
| Weight loss | 2 | ||
| Weight loss maintenance | 2 | ||
| Weight maintenance | 2 | ||
*, Range is based on means from the studies; BMI, body mass index; C, control group; CHO, carbohydrate, d, day; E%, energy percentage; HF, high fat (range: 40–50 E%); HP, high protein (range: 20–59 E%); I, intervention group; SP, standard protein (range: 2–20 E%).