Table 1 Summary of results from Asian observational studies on diet and gestational diabetes

Asadi M, et al. 2019 [19]

Iran- Asia

n:278 cases:130 controls:148

case-control

women aged 19–40 years who came from six healthcare centres between 2014 and 2015

pre-pregnancy dietary pattern

Prudent dietary pattern: Odds Ratio (OR) = 0.88, 95% Confidence Interval (CI): 0.44–0.99, p-trend = 0,02

Sedaghat F, et al. 2017 [20]

Iran- Asia

n: 388 cases:122 controls:266

case-control

women aged 18–40 years who visited major general hospitals 2009–2010

pre-pregnancy dietary pattern

Western dietary pattern: OR = 1.97, 95% CI: 1.27–3,04

Lamyian M, et al. 2017 [21]

Iran- Asia

n: 1026

cohort

women aged 18–45 years who visited 5 universities of medical sciences’ hospitals 2010–2011

pre-pregnancy fast food consumption

Total fast food consumption: OR = 2.12 95% CI: 1.12–5.43, p-trend = 0.03; french fries: OR = 2.18 95% CI: 1.05–4.70, p-trend = 0.12

Zamani B. et al. 2019 [22]

Iran- Asia

n:460 cases:200 controls:260

case-control

women aged 22–44 years who visited the nutrition clinic in AL-Zahra and Shahid Beheshti hospitals, Isfahan. Gestational age between 25 and 28 weeks

pregnancy plant-based diet (PDI)

Higher PDI score: OR = 0.47; 95% CI: 0.28–0.78, P = 0.004

Zareei S. et al. 2018 [23]

Iran - Asia

n: 204 cases:104 controls:100

case-control

women who visited the maternity ward of Valiasr Hospital in Fasa Town, 2016. No data about gestational age

pregnancy dietary pattern

Unhealthy dietary pattern: OR = 2.838 95% CI: 1.039–7.751, p-value: 0.042; healthy dietary pattern: OR = 0.284,95% CI:0.096–0.838, p-value: 0.023

Du HY et al. 2017 [24]

China - Asia

n: 753

cohort

women who visited the Maternal and Child Health Care Hospital in China, 2013–2014. Gestational age between 5 and 15 weeks.

pregnancy dietary pattern

Western pattern: OR = 4.40, 95% CI: 1.58–12.22, p-trend: 0.004); traditional pattern: OR = 4.88, 95% CI: 1.79–13.32, p-trend: 0.002)

Chen Q. et al. 2020 [25]

China - Asia

n: 9556 cases:1464 controls:8092

case-control

women who visited the First Affiliated Hospital of Shanxi Medical University in China, 2012–2016.

pre-pregnancy and pregnancy dietary pattern

Vegetable pattern 1 year prior to conception OR = 0.94; 95% CI: 0.89–0.99, p-trend: 0,025; first trimester of pregnancy OR = 0.94; 95% CI: 0.89–0.99, p-trend: 0,018; second trimester of pregnancy OR = 0.91; 95% CI: 0.86–0.96, p-trend: < 0.001

Zhou X et al. 2018 [26]

China - Asia

n:2755

cohort

pregnant women from the Tongji Maternal and Child Health Cohort. They have visited the maternity clinic in one of three public hospitals in Wuhan, China, since 2013–2016. Gestational age between 8 and 16 weeks.

pregnancy dietary pattern

High Fish-meat-eggs scores (OR for quartile 4 vs. quartile 1 = 1.83; 95% CI 1.21, 2.79; p = 0·007); high rice-wheat-fruits scores (OR for quartile 3 v. quartile 1 = 0.54; 95% CI 0.36, 0.83; p = 0.010)

Dong H et al. 2021 [27]

China - Asia

n: 1455

cohort

women > 12 weeks gestations who visited the Sichuan Provincial Hospital for Women and Children, Southwest China, 2017

pregnancy dietary pattern

Overall Low carbohydrate dietary (LCD) pattern RR = 1.24, 95% CI 1.01–1.52, p = 0.026

Chen Q. et al. 2019 [28]

China, Asia

n: 9556 cases:1464 controls:8092

case-control

women who visited the First Affiliated Hospital of Shanxi Medical University in China, 2013–2016.

pre-pregnancy and pregnancy vitamin dietary pattern

Vitamin dietary pattern 1 year prior to conception: OR = 0.90; 95% CI: 0.85–0.95, p-trend: < 0.0001; first trimester of pregnancy OR = 0.90; 95% CI: 0.86–0.95, p-trend: < 0.0001; second trimester of pregnancy OR = 0.90; 95% CI: 0.85–0.95, p-trend: < 0.0001

Liu C et al. 2020 [29]

China - Asia

n: 3009

cohort

women who visited the First Affiliated Hospital of Shanxi Medical University in China, 2013–2016. Gestational age < 16 weeks.

pregnancy vitamin C intake

Above adequate dietary vitamin C intake OR = 0.68, 95% CI: 0.49–0.95.

Saraf-Bank S et al. 2018 [30]

Iran - Asia

n: 463 cases:200 controls:263

case-control

pregnant women aged 22–44 years who visited the Nutrition Clinic of Isfahan and Shahid Beheshti Hospital as well as Azzahra Hospital. Gestational age between 5 and 28 weeks.

dietary acid intake

Highest tertile of potential renal acid load (PRAL): OR = 9.27; 95% CI: 4.00–21.46, p-trend: < 0,001

Parast VM et al. 2017 [31]

Iran - Asia

n: 80 cases:40 controls:40

case-control

pregnant women who visited the Department of Obstetrics and Gynecology of the Shahid Beheshti Hospital, 2016. Gestational age between 24 and 28 weeks

antioxidant nutrients intake

Total capacity antioxidant (TAC): OR 9.6; 95% CI: 3.4–26.8); p value: < 0.001; intakes of vitamin E OR = 1.5; 95% CI: 1.2–1.9; p value: < 0.001; intakes of selenium OR = 8.2; 95% CI: 1.3–52.0; p value: 0.026; intakes of zinc OR = 1.7; 95% CI: 1.2–2.5; p value: < 0.001

Gao Q et al. 2019 [32]

China- Asia

n: 1978

cohort

pregnant women with maternal age > 18 years, who visited three public hospitals in Wuhan, 2013–2016. Gestational age between 8 and 16 weeks.

carotenoids and lycopene intake

Highest quartile of lycopene intake OR = 0.50; 95% CI 0.29, 0.86; p-trend = 0·007)

Kyozuka H et al. 2021 [33]

Japan - Asia

n: 92764

cohort

Japanese women from the Japan Environment and Children’s Study (JECS), 2011–2014.

pre-pregnancy antioxidant nutrients intake

Quintil 5 Selenium intake OR = 1.15, 95% CI: 1.01–1.30; quintil 1 Se intake: OR: 1.19, 95% CI: 1.01–1.41

Daneshzad E et al. 2020 [34]

Iran - Asia

n: 463 cases:200 controls:263

case-control

pregnant women aged 22–44 years who visited the Nutrition Clinic of Isfahan, Iran. Gestational age between 25 and 28 weeks.

antioxidants and Vitamin C intake

3 tertil of FRAP (ferric reducing ability of plasma) OR = 0.26, 95% CI: 0.16–0.42; p = < 0.0001

Aljanahi A et al. 2020 [35]

Saudi Arabia - Asia

n: 121 cases:72 controls:49

case-control

pregnant women aged 19–45 years who visited the King Fahad University Hospital, Maternal and Children Hospital and Family Medicine of Imam Abdulrahman Bin Faisal University. No data about gestational age.

vitamin D intake, dairy products and eggs consumption

Vitamin D

dietary intake is higher among controls compared to cases (p-value: 0.021); vitamin C and eggs intake is higher among cases compared to controls (p = 0.004; p = 0.040); fortified orange juice OR = 3.2; 95% CI: 1.2–8.8, p-value: 0.026; fortified yogurt OR = 3; 95% CI: 1.1–8.6, p-value: 0.04; low-fat milk OR = 3.2; 95% CI 1.3–7.7; p-value 0.01; full-fat milk OR = 0.4; 95% CI: 0.2–0.8; p-value: 0.017

Li H, et al. 2021 [36]

China - Asia

n: 2987

cohort

women with a median age of 28.5 ± 3.6 years old. They were from Clinic of the General Hospital of Chinese People’s Armed Police Forces, 2013–2014. Gestational age between 13 and 28 weeks.

fruits, vegetable and fruit juice intake during pregnancy

No association with total fruit and vegetable consumption. A higher quantity of grape, melon, potatoes and fruit juice were positively associated with GDM. A higher quantity of apple, orange and potatoes were negatively associated with GDM (p < 0,05).

Yong HY, et al. 2021 [37]

Malaysia - Asia

n: 452

cohort

Women from three maternal child health (MCH) clinics. No data about age

pre-pregnancy and pregnancy consumption of beverage

higher fruit juice intake before pregnancy: AOR = 0.98, 95% CI = 0.97–0.99. In the first trimester: AOR = 0.92, 95% CI = 0.89–0.98)

A higher intake of cultured-milk drinks before pregnancy: AOR = 1.03, 95% CI = 1.01–1.08. In the first trimester: AOR = 1.07, 95% CI = 1.02–1.12.

Liu YH et al. 2022 [38]

China - Asia

cases: 143 controls: 345

case-control

no data available

pregnancy dietary patterns

Dietary pattern 2: OR = 2.96, 95% CI: 0.939–9.356, P = 0.004

Wang H et al. 2021 [39]

China - Asia

n: 2099

cohort

pregnant women were part of the participants in the Tongji Maternal and Child Health Cohort (TMCHC) study, 2013–2016. Gestational age between 8 and 16 weeks.

pregnant plant-based diet index (PDI)

Highest quartile of PDI: OR 0.43; 95% CI 0.24, 0.77; p = 0.005

Zhang X et al. 2021 [40]

China- Asia

n: 9317

cohort

women from public hospitals with obstetric services in South China, 2014–2017.

pre-pregnancy and pregnancy dietary glycemic index, glycemic load and fiber intake

Highest tertile respect to lowest tertile Glycemic index pre-pregnancy: OR 1.12 (95% CI 1.03, 1.19) p = 0.01 1st trimester: OR 1.25 (95% CI 1.20, 1.33) p = 0.008 2nd trimester: OR 1.29 (95% CI 1.21, 1.48) p = 0.005 Glycemic load pre-pregnancy: OR 1.15 (95% CI 1.08, 1.23) p = 0.02 1st trimester: OR 1.23 (95% CI 1.10, 1.45) p = 0.01 2nd trimester: OR 1.25 (95% CI 1.11, 1.40) p = 0.01 Fiber intake pre-pregnancy: OR 0.89 (95% CI 0.83, 0.94) p = 0.03 1st trimester: OR 0.83 (95% CI 0.75, 0.91) p = 0.01 2nd trimester: OR 0.82 (95% CI 0.73, 0.91) p = 0.01