Efficacy of Intermittent or Continuous Very Low-Energy Diets in Overweight and Obese Individuals with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analyses

Table 4

The GRADE evidence of VLEDs compared to bariatric surgery for overweight and obese people with type 2 diabetes mellitus.

Quality assessment

No. of patients

Effect

Quality

Importance

No. of studies

Design

Risk of bias

Inconsistency

Indirectness

Imprecision

Other considerations

VLED

Bariatric surgery

Relative (95% CI)

Absolute

Weight

4

Randomized trials

Serious^1

No serious inconsistency

No serious indirectness

Serious^2

None

42

42

—

MD -3.14 lower (-10.04 lower to 3.67 higher)

Low

9

Glucose (better indicated by lower values)

5

Randomized trials

Serious^1

No serious inconsistency

No serious indirectness

Serious^2

None

69

55

—

MD 0.37 higher (-0.22 lower to 0.96 higher)

Low

8

TG (better indicated by lower values)

4

Randomized trials

Serious^1

No serious inconsistency

No serious indirectness

Serious^2

None

57

40

—

MD -0.04 lower (-0.25 lower to 0.17 higher)

Low

7

HOMA-IR (better indicated by lower values)

4

Observational studies^3

No serious risk of bias

Serious^4

No serious indirectness

Serious^2

None

60

—

—

Very low

6

46

MD -1 lower (-2.7 lower to 0.7 higher)

CI: confidence interval; OR: odds ratio. 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. ¹Some studies were nonrandomized controlled trials. ²The ratio of 95% CI to the effect is more than 50%. 95% CI is wider and its accuracy is poor, so it decreases one level. ³Case-control. ⁴The value of the combined results is larger, and there is statistical heterogeneity, so it falls by one grade.