Table 1.
Characteristics of included studies.
| Study ID | Country | Study type length | No. of patients |
BMI category | Age (Year) | PCOS diagnosis | Intervention type | Comparators | Outcome | Quality of evidence | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| G1 | G2 | ||||||||||
| Marsh et al. 2010 [35] | Australia | Parallel 3 months | 50 | 46 | Overweight and obese | 18–40 | Rotterdam criteria [41] | LGID | CHD | The beneficial rule of LGID in the management of PCOS | Low∧% |
| Mehrabani et al. 2012 [36] | Iran | Parallel 3 months | 30 | 30 | Overweight and obese | 20–40 | Rotterdam criteria and mF-G score [42] | LGID + MHCD | CHCD | Significantly led to reduced body weight and androgen levels | Moderate% |
| Asemi et al. 2014 [33] | Iran | Parallel 3 months | 27 | 27 | Overweight and obese | 18–40 | Rotterdam criteria and mF-G score | LGID DASH-style diet | CD | Significantly reduction in LDL and increase in TAC and GSH levels | Moderate% |
| Panico et al. 2014 [37] | Italy | Cross-over 3 months | 15 | 15 | Overweight | 18–40 | Rotterdam criteria | LGID | HGID | Improves insulin resistance and serum androgen levels | High |
| Turner-McGrievy et al. 2014 [39] | USA | Parallel 6 months | 9 | 9 | Overweight and obese | 18–35 | Rotterdam criteria | LGID-vegan | LCD | Effective for promoting short-term weight loss | Moderate% |
| Sordia-Hernández et al. 2016 [38] | Mexico | Parallel 3 months | 20 | 20 | Overweight | 18–35 | Rotterdam criteria | LGID | NGID | Improves insulin resistance and serum androgen levels | Low∧% |
| Wong et al. 2016 [40] | USA | Parallel 3 months | 9 | 10 | Overweight and obese | 13–21 | Rotterdam criteria | LGID | LFD | Beneficial for weight control but did not attenuate biochemical hyperandrogenism | Moderate% |
| Kazemi et al. 2019 [34] | Canada | Parallel 12 months | 47 | 48 | Overweight and obese | 18–35 | Rotterdam criteria | LGID pulse-based diet, | TLC | Improve cardio-metabolic disease risk factors | High |
LGID, Low glycemic index diet; CHD, conventional healthy diet; CHCD, conventional hypocaloric diet; MHCD, modified hypocaloric diet; mF-G score, Modified Ferriman–Gallwey score; DASH, Dietary Approaches to Stop Hypertension; CD, Control diet; insulin, triglycerides and low-density lipoprotein cholesterol (LDL-c); TAC, plasma total antioxidant capacity; GSH, total glutathione; HGID, High glycemic index diet; LCD, Low calorie diet; NGID, normal glycemic diet; LFD, Low fat diet; TLC, Therapeutic Lifestyle Changes; Factors downgrading any specific evidence: ∗ Limitations (risk of bias), $ Inconsistency of results, # indirectness of results, % Imprecision, ^ Publications bias; GRADE 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.