Table 2.
Summary of findings
|
Low carbohydrate compared with high-carbohydrate diet in patients with type 2 diabetes | |||||
|---|---|---|---|---|---|
|
Population: patients with type 2 diabetes Intervention: Low carbohydrate, <45 E%, higher protein and/or fat Comparison: High carbohydrate, E% 45–60% | |||||
| Illustrative comparative risks* (95% CI) |
Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | ||
| Outcomes | Assumed risk | Corresponding risk | |||
| High-carbohydrate diet (control) | Low-carbohydrate diet | ||||
| BMI kg/m2 within 1 year | The mean BMI in the intervention groups was 1.02 lower (2.58 lower to 0.54 higher) |
185 (4 studies) |
⊕⊕⊕⊝ moderate† |
||
| BMI kg/m2 at 1 year or later | The mean BMI ≥1 in the intervention groups was 0.43 lower (1.38 lower to 0.53 higher) |
159 (2 studies) |
⊕⊕⊕⊝ moderate† |
||
| Weight (kg) within 1 year | The mean weight (kg)<1 year in the intervention groups was 0 higher (1.03 lower to 1.02 higher) |
741 (7 studies) |
⊕⊕⊕⊕ high‡ |
||
| Weight (kg) at 1 year or later | The mean weight (kg) in the intervention groups was 0.2 higher (0.97 lower to 1.36 higher) |
771 (6 studies) |
⊕⊕⊕⊕ high‡ |
||
| HbA1c (%) within 1 year | The mean HbA1c (%) in the intervention groups was 0.34 lower (0.06 to 0.63 lower) |
809 (8 studies) |
⊕⊕⊕⊝ moderate§ |
||
| HbA1c (%) at 1 year or later | The mean HbA1c (%) in the intervention groups was 0.04 higher (0.04 lower to 0.13 higher) |
839 (7 studies) |
⊕⊕⊕⊕ high‡ |
||
| LDL cholesterol (mmol/L) within 1 year |
The mean LDL cholesterol in the intervention groups was 0.04 higher (0.06 lower to 0.13 higher) |
809 (8 studies) |
⊕⊕⊕⊕ high‡ |
||
| LDL cholesterol (mmol/L) at 1 year or later | The mean LDL cholesterol in the intervention groups was 0.01 lower (0.1 lower to 0.07 higher) |
839 (7 studies) |
⊕⊕⊕⊕ high‡ |
||
| SF-36 QOL Physical component score, longest follow-up. Higher=better | The mean QOL physical component score in the intervention groups was 1.93 lower (4.02 lower to 0.16 higher) |
348 (2 studies) |
⊕⊕⊕⊝ moderate¶ |
||
| SF-36 QOL Mental component score, longest follow-up. Higher=better | The mean QOL mental component score in the intervention groups was 0.74 higher (1.24 lower to 2.71 higher) |
348 (2 studies) |
⊕⊕⊕⊝ moderate¶ |
||
| Dropout (end of study) | 229 per 1000 | 259 per 1000 (215 to 314) |
RR 1.13 (0.94 to 1.37) |
1182 (7 studies) |
⊕⊕⊕⊝ moderate¶ |
GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.
*The basis for the assumed risk (eg, the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). RR, risk ratio.
†CI does not rule out a beneficial effect of low-carbohydrate diet.
‡No relevant clinical difference (narrow CI).
§High I2, heterogeneity, many studies show no difference.
¶CI does not rule out any difference.