Table 6.
Comparison 2: diet-only intervention versus usual care (additional outcomes)
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) |
Participants, n (studies) |
Certainty of the evidence (GRADE) |
|
| Risk with usual care | Risk with diet | ||||
| BMI (kg/m2) | The mean BMI was 27.86 kg/m2. | MD 0.39 kg/m2 lower (from 0.64 lower to 0.14 lower) |
– | 1415 (7 RCTs) |
⊕⊕⊕⊕High |
| Weight change (kg) | The mean weight was 73.37 kg. | MD 1.35 kg lower (from 2.38 lower to 0.32 lower) |
– | 1563 (9 RCTs) |
⊕⊕⊕◯ Moderate† |
| Weight change (kg), medications | The mean weight, medications was 70.00 kg. | MD 1.06 kg lower (from 4.07 lower to 1.95 higher) |
– | 349 (2 RCTs) |
⊕◯◯◯ Very low‡§¶ |
| Weight change (kg), no medications | The mean weight, no medications was 76.75 kg. | MD 0.74 kg lower (from 1.22 lower to 0.26 lower) |
– | 1154 (6 RCTs) |
⊕⊕⊕⊕High |
| FPG (mmol/L) | The mean FPG was 5.17 mmol/L. | MD 0.18 mmol/L lower (from 0.33 lower to 0.03 lower) |
– | 1412 (7 RCTs) |
⊕⊕⊕◯ Moderate† |
| Waist circumference (cm) | The mean waist circumference was 97.34 cm. | MD 0.25 cm lower (from 0.82 lower to 0.31 higher) |
– | 641 (5 RCTs) |
⊕⊕⊕⊕High |
| HOMA-IR | The mean HOMA-IR was 4.70 | MD 0.02 lower (from 0.48 lower to 0.43 higher) |
– | 371 (2 RCTs) |
⊕⊕⊕◯ Moderate‡ |
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
†Pavithran et al69 has a high ROB with some uncertainties in the assessment. ROB, risk of bias
‡OIS is not met when high-risk studies are removed.
§High ROB that possibly contributes to the inconsistency with I2 statistic = 81%,
¶I2 statistic = 81%, p=0.02, implying significant heterogeneity without a lot of overlap in CIs.
BMI, body mass index; CI, confidence interval; FPG, fasting plasma glucose; HOMA-IR, homeostatic model assessment of insulin resistance; MD, mean difference; RCT, randomised controlled trial; ROB, risk of bias.