Summary of findings 1. Summary of findings table ‐ Low‐carbohydrate weight‐reducing diets compared to balanced‐carbohydrate weight‐reducing diets in overweight and obese participants without T2DM (weight‐reducing phase only).
| Low‐carbohydrate weight‐reducing diets compared to balanced‐carbohydrate weight‐reducing diets in overweight and obese participants without T2DM (weight‐reducing phase only) | ||||||
| Patient or population: overweight and obese participants without T2DM (weight‐reducing phase only) Setting: outpatient clinics, medical/research centres in high‐income countries Intervention: low‐carbohydrate weight‐reducing diets Comparison: balanced‐carbohydrate weight‐reducing diets | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with balanced‐carbohydrate weight‐reducing diets | Risk with low‐carbohydrate weight‐reducing diets | |||||
| Change in body weight (kg) at 3 to < 12 months | The mean change in body weight (kg) at 3 to < 12 months ranged from ‐11.34 to ‐2.3 kg | MD 1.07 kg lower (1.55 lower to 0.59 lower) | ‐ | 3286 (37 RCTs) | ⊕⊕⊕⊝ Moderatea | Low‐carbohydrate weight‐reducing diets probably result in little to no difference in change in weight at 3 to 8.5 months. |
| Change in body weight (kg) at ≥ 12 months | The mean change in body weight (kg) at ≥ 12 months ranged from ‐11.6 to ‐1.7 kg | MD 0.93 kg lower (1.81 lower to 0.04 lower) | ‐ | 1805 (14 RCTs) | ⊕⊕⊕⊝ Moderatea | Low‐carbohydrate weight‐reducing diets probably result in little to no difference in change in weight (kg) at 1 to 2 years. |
| Number of participants per group with weight loss of at least 5% at ≥ 12 months | 789 per 1000 | 875 per 1000 (741 to 1000) | RR 1.11 (0.94 to 1.31) | 137 (2 RCTs) | ⊕⊝⊝⊝ Very lowb,c | The evidence is very uncertain about the effect of low‐carbohydrate weight‐reducing diets on number of participants per group with weight loss of at least 5% at 1 year. |
| Cardiovascular mortality ‐ not measured | ‐ | ‐ | ‐ | ‐ | ‐ | |
| Change in DBP (mmHg) at ≥ 12 months | The mean change in DBP (mmHg) at ≥ 12 months ranged from ‐11 to 2.9 mmHg | MD 0.09 mmHg lower (1.29 lower to 1.12 higher) | ‐ | 1419 (11 RCTs) | ⊕⊕⊕⊝ Moderatea | Low‐carbohydrate weight‐reducing diets probably result in little to no difference in change in DBP at 1 to 2 years. |
| Change in LDL cholesterol (mmol/L) at ≥ 12 months | The mean change in LDL cholesterol (mmol/L) at ≥ 12 months ranged from ‐0.31 to 0.1 mmol/L | MD 0.04 mmol/L higher (0.05 lower to 0.12 higher) | ‐ | 1494 (13 RCTs) | ⊕⊕⊕⊝ Moderatea | Low‐carbohydrate weight‐reducing diets probably result in little to no difference in change in LDL cholesterol at 1 to 2 years. |
| Constipation at 3 to < 12 months | 267 per 1000 | 283 per 1000 (216 to 368) | RR 1.06 (0.81 to 1.38) | 564 (4 RCTs) | ⊕⊝⊝⊝ Very lowa,d | The evidence is very uncertain about the effect of low‐carbohydrate weight‐reducing diets on constipation at 3 to 6 months. |
| *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). CI: confidence interval; MD: mean difference; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
| See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_420942855893718659. | ||||||
a Serious risk of bias: The majority of information is from studies at high overall risk of bias b Serious risk of bias: All information is from a study at high overall risk of bias c Very serious imprecision: OIS not met; 95% CI for the pooled estimate is consistent with the possibility for important benefit (245 per 1000 absolute increase) and unimportant harm (47 per 1000 absolute reduction) d Very serious imprecision: OIS not met; 95% CI for the pooled estimate is consistent with the possibility for unimportant benefit (51 per 1000 absolute reduction) and for important harm (101 per 1000 absolute increase)