Table 1 Reviews and experimental studies investigating the effects of diet on polycystic ovary syndrome outcomes
From: Lifestyle management in polycystic ovary syndrome – beyond diet and physical activity
Dietary intervention | N study design | N studies; N participants | Main findingsa | References |
|---|---|---|---|---|
Low CHO | 2 SR/MA (27 RCT total - 18 RCT using low CHO diet) [56, 85] 1 SR (5 RCT total - 1 RCT using low CHO diet) [16] | 14; 901 | Low CHO compared with control diets [56]: ↓ BMI, HOMA-IR, TC, LDL-C ↑ SHBG ↔ LH, T, HDL-C Dietary intervention ↓HOMA-IR, FINS, FGL, BMI, BW, WC compared with minimal intervention, and subgroup analysis showed no additional benefits for low CHO diets [85] Weight loss improved the presentation of PCOS regardless of dietary composition, with no subtle differences observed for low CHO diets [16] | Shang et al. 2020 [85] Zhang et al. 2019 [56] Moran et al. 2013 [16] |
Low GI | 1 SR/MA (10 RCT total - 8 RCT using low GI diet) [55] 1 SR (5 RCT total - 1 RCT using low GI diet) [16] 4 Pre-post prospective [61, 76, 77, 118] 1 RCT [78] | 16b; 582 | High GI compared with low GI diets [55]: ↓ HOMA-IR, FINS, TC, LDL-C, TAG, WC, T ↔ FGL, HDL-C, BW, FAI Low GI diets had greater improvements in IR, TC, HDL-C, fibrinogen, menstrual regularity and QoL [16] Low GI diets followed for ≥ 12 weeks: ↓ BW [76, 77], BMI [76, 77], BFM [77], WC [77], WHR [77], FINS [76, 77], FGL [77], TC [77], LDL-C [77], TAG [77], T [77], LH [77], androstenedione [77], prolactin [77] ↑ insulin sensitivity (HOMA2-IS) [61], synthesis of predominantly anti-inflammatory eicosanoid mediators (e.g. 16(R)/16(S)-HETE, 13(S)-HODE, 9(S)-HODE, 15(S)-HETE, 12(S)-HETE, 5(S)-oxoETE, 5(S)-HETE)) [118], fasting glucagon (higher glucagon levels associated with lower levels of self-reported hunger) [78] | Kazemi et al. 2020 [55] Moran et al. 2013 [16] Shishrehgar et al. 2019 [76] Barr et al. 2016 [61] Szczuko et al. 2018 [77] Szczuko et al. 2017 [118] Hoover et al. 2021 [78] |
High protein | 1 SR (5 RCT total - 3 RCT using high protein diet) [16] | 11; 308 | High protein diets improve depression and self-esteem [16] ↓ BFM [74, 97], BW [73, 74, 97], BMI [73, 74], WC [73, 74, 97], WHR [73], FINS [74, 98], FGL [97], HOMA-IR [73, 98], TAG [73], VLDL-C [73], T [73, 98], Ferriman-Gallway scores [73] High protein and standard/low protein diet ↓ BW [92, 94, 95], BMI [92, 94, 95], BFM [95], WC [92, 94], WHR [94], FINS [95, 96], HOMA-IR [95], TAG [96], LDL-C [98] CRP [96], MPA [96], leptin [95], T [98], DHEAS [98], FAI [98] and there was ↔ between high and standard/low protein diets | Moran et al. 2013 [16] Moran et al. 2010 [96] Moran et al. 2004 [95] Sorensenet et al. 2012 [97] Toscani et al. 2011 [92] Nadjarzadeh et al. 2021 [94] Phy et al. 2015 [73] Pohlmeier et al. 2014 [74] Mehrabani et al. 2012 [98] |
Low fat | 1 SR/MA (19 RCT total - 1 RCT using low fat diet) [85] 1 SR (5 RCT total - 1 RCT using low fat diet) [16] 1 RCT [107] | 3; 137 | Dietary intervention ↓HOMA-IR, FINS, FGL, BMI, BW, WC compared with minimal intervention, and subgroup analysis showed no additional benefits for low fat diets [85] Weight loss improved the presentation of PCOS regardless of dietary composition, with no subtle differences observed for low fat diets [16] Low fat (25% E fat) ↓ BW, BFM, BMI though there was ↔ between low fat and standard fat (35% E fat) diets [107] | Shang et al. 2020 [85] Moran et al. 2013 [16] Wong et al. 2016 [107] |
Fatty acids | 1 SR (5 RCT total - 1 RCT using MUFA enriched diet) [16] 1 controlled trial (not randomised) [103]c | 5; 146 | MUFA enriched diets may produce greater weight loss when compared to other dietary patterns [16] MUFA enriched compared with PUFA enriched diets ↓ FGL [103], glucose response to OGTT [103], HgBA1 [102] Diets with a higher alpha-linolenic acid, lower omega-6/omega-3 ratio and saturated fat content ↓ TAG, TC/HDL-C, LDL-C-/HDL-C, TAG/HDL-C, and HOMA-IR [105] High total and saturated fat meals compared with high fibre low fat meals produce prolonged ↓ in T [86] | Moran et al. 2013 [16] Yahay et al. 2021 [105] Kalgaonkar et al. 2011 [102] Kasim-Karakas et al. 2004 [103] Katcher et al. 2009 [86] |
DASH | 1 SR/MA (19 RCT total - 4 RCT using DASH diet) [85] | 4; 228 | Dietary intervention ↓ HOMA-IR, FINS, FGL, BMI, BW, WC compared with minimal intervention, and subgroup analysis showed DASH diet was more effective at improving insulin sensitivity [85] | Shang et al. 2020 [85] |
Plant-based | 3 RCT | 3; 108 | Plant-based (35% animal protein, 35% textured soy protein, 30% vegetable protein) compared to control (70% animal protein, 30% vegetable protein) ↓ BMI, FGL, FINS, TAG, HOMA-IR, T, MDA and ↑ QUICKI [67] Plant-based and control diets (calorie restriction [68] and general dietary recommendations [72]) ↓ BW [68], HOMA-IR [72], T [72], LH/FSH [72] and there was ↔ between plant-based and control diets | Turner-McGrievy et al. 2014 [68] Kazemi et al. 2020 [72] Karamali et al. 2018 [67] |
Meal pattern | 1 RCT | 1; 40 | 6 meals/day compared with 3 meals/day: ↓ FINS ↑ post-OGTT insulin sensitivity | Papakonstantinou et al. 2016 [111] |
Meal timing | 1 RCT | 1; 60 | Consuming a high kilojoule breakfast compared with a high kilojoule dinner: ↓ FGL, FINS, HOMA-IR, T ↑ SHBG | Jakubowicz et al. 2013 [66] |