Table 2.

Results for fertility outcomes stratified by nutritional component in women conceiving via ART.

Category	Studies	Live birth	Clinical pregnancy	Implantation	Fertilization rate	IVF-specific (embryo and oocyte characteristics)
ENERGY AND MACRONUTRIENTS
Protein	1	+ve: increasing quartiles of fish, also when replacing other meat, other protein-rich food (Nassan et al., 2018). NS: total meat intake, eggs, vegetable source of protein (Nassan et al., 2018).	NS: total meat intake, eggs, vegetable source of protein (Nassan et al., 2018).	NS: total meat intake, eggs, vegetable source of protein (Nassan et al., 2018).	–	–
CHO	1	NS: total CHO (Noli et al., 2020).	NS: total CHO Noli et al. (2020).	–	–	NS: embryo transfer: total CHO (Noli et al., 2020).
GI/GL	1	NS: Noli et al. (2020).	NS: Noli et al. (2020).	–	–	NS: embryo transfer (Noli et al., 2020).
Fats and FAs	1	+ve: increasing DHA + EPA consumption (Salas-Huetos et al., 2022). NS: total omega-3 consumption (Salas-Huetos et al., 2022).	NS: all fats and fatty acids (Salas-Huetos et al., 2022).	NS: all fats and fatty acids (Salas-Huetos et al., 2022).	–	–
CORE FOOD GROUPS
Dairy	1	+ve: increasing calorie and age-adjusted dairy intake in women >35 years old (Afeiche et al., 2016). NS: full-fat or low-fat dairy (Afeiche et al., 2016).	–	–	–	–
Whole grains	2	+ve: increasing whole grain intake (g/day) (Gaskins et al., 2016). NS: Noli et al. (2020).	NS: Noli et al. (2020).	–	–	+ve: Endometrial thickness: Increasing whole grain intake (g/day) (Gaskins et al., 2016). NS: Embryo transfer (Noli et al., 2020).
Fish/seafood	1	+ve: Q1 vs Q4 total fish consumption (Salas-Huetos et al., 2022).	NS: total fish consumption (Salas-Huetos et al., 2022).	NS: total fish consumption (Salas-Huetos et al., 2022).	–	–
Fruits and vegetables	1	Total fruits and vegetables: NS (Chiu et al., 2018b)	Total fruits and vegetables: NS (Chiu et al., 2018b)	Total fruits and vegetables: NS (Chiu et al., 2018b).	–	–
DISCRETIONARY FOODS
Sugar-sweetened beverages	1	+ve: Reducing cups of sugared soda/day (Machtinger et al., 2017).	–	–	–	−ve: oocytes retrieved, mature oocytes retrieved, fertilized oocytes: SSB consumption compared to none (Machtinger et al., 2017). NS: diet soda (Machtinger et al., 2017).
PHYTOESTROGENS
Soy and other	1	+ve: any soy isoflavone intake vs none (Vanegas et al., 2015).	+ve: any soy isoflavone intake vs none (Vanegas et al., 2015).	NS: soy isoflavone intake (Vanegas et al., 2015).	+ve: any soy isoflavone intake vs none (Vanegas et al., 2015).	–
WHOLE DIETS
Fertility diet	1	NS (Gaskins et al., 2019).	NS (Gaskins et al., 2019).	NS (Gaskins et al., 2019).	–	–
MedDiet/aMedDiet	5	+ve: increasing dietary adherence (Gaskins et al., 2019). +ve: increasing dietary adherence in women <35 years old (Karayiannis et al., 2018).	+ve: increasing dietary adherence in women >35 years old (Ricci et al., 2019). +ve: increasing dietary adherence (Vujkovic et al., 2010). NS (Sun et al., 2019) +ve: increasing dietary adherence in women <35 years old (Karayiannis et al., 2018).	NS (Sun et al., 2019). NS (Karayiannis et al., 2018).	NS (Vujkovic et al., 2010).	−/+ve: viable embryos: increasing dietary adherence (Vujkovic et al., 2010). +ve: fertilized oocytes and embryo yield: increasing dietary adherence (Sun et al., 2019). NS: embryo quality (Vujkovic et al., 2010). NS: number of good-quality embryos, good-quality oocytes, embryo transfer (Ricci et al., 2019).
Profertility diet	1	+ve: increasing dietary adherence (Gaskins et al., 2019).	+ve: increasing dietary adherence (Gaskins et al., 2019).	+ve: increasing dietary adherence (Gaskins et al., 2019).	–	–
aHEI-2010	1	NS (Gaskins et al., 2019).	NS (Gaskins et al., 2019).	NS (Gaskins et al., 2019).	–	–
Healthy diet/unhealthy diet	1	–	−ve: T2 vs T1 ‘unhealthy diet’ adherence (Jahangirifar et al., 2019). NS (Jahangirifar et al., 2019).	–	NS (Jahangirifar et al., 2019).	+ve: total oocytes: T3 vs T1 dietary adherence (Jahangirifar et al., 2019).
DII	1	–	–	–	NS (Diba-Bagtash et al., 2021).	NS: quantity of retrieved and fertilized oocytes. NS: embryo transfer (Diba-Bagtash et al., 2021).

aHEI-2010, alternative healthy eating index 2010; aMED, alternative Mediterranean diet; CHO, carbohydrates; DHA, docosahexaenoic acid; DII, dietary inflammatory index; EPA, Eicosapentaenoic acid; FAs, fatty acids; GI/GL, glycemic index/glycemic load; MedDiet, Mediterranean diet; NS, not significant; −ve/+ve, negative/positive; SSB, sugar sweetened beverages.