Table 2.

Main characteristic of included studies; ketogenic diet as a potential intervention for polycystic ovary syndrome

Authors	Country	Patients	Total sample size	Study design	Interventions	Duration	Outcomes
Cincione et al. (2023) [13]	Italy	PCOS patients with overweight or obesity	144	RCT	The very-low-calorie ketogenic diet in this study included the maximum intake of carbohydrates was set at 30 g per day and the total caloric intake per day was established at around 600 kcal	6 weeks	Glucose, HOMA-IR, LH, FSH, total testosterone, SHBG,
Li et al. (2021) [14]	China	PCOS and liver dysfunction who were obese	18	RCT	The ketogenic diet was composed of approximately 5%–10% of energy derived from carbohydrates (≤ 50 g/day), 18%–27% from protein, and 70%–75% from fat	12 weeks	Glucose, LH, FSH, total testosterone, TG, TC, LDL, HDL
Pandurevic et al. (2023) [27]	Italy	obese women with PCOS	30	RCT	The low carbohydrate ketogenic diet in this study included consumption of less than 50g of carbohydrates per day, primarily from vegetables, along with a daily intake of 10g of olive oil	16 weeks	Glucose, HOMA-IR, total testosterone, SHBG, TG, TC, LDL, HDL
Cincione et al. (2021) [20]	Italy	obese women with PCOS	17	Before-after trial	The ketogenic diet followed with daily intake of carbohydrates was limited to 30g	6 weeks	Glucose, HOMA-IR, LH, FSH, total testosterone, SHBG, TG, TC, LDL, HDL
Avolio et al. (2020) [21]	Italy	PCOS women, ages 18–38 years	57	Before-after trial	The low carbohydrate ketogenic diet involved limiting the daily carbohydrate intake to less than 20g	24 weeks	HOMA-IR
Mavropoulos et al. (2005) [22]	USA	Overweight and obese women with PCOS	5	Before-after trial	The low carbohydrate ketogenic diet involved consuming fewer than 20 g of carbohydrates per day	24 weeks	Glucose, total testosterone, TG, TC, LDL, HDL
Jian et al. (2022) [23]	China	Overweight and obese women with PCOS	51	Before-after trial	The ketogenic diet involved a daily intake of 50 g or less of carbohydrates	4 weeks	Glucose, TG, TC, LDL, HDL
Magagnini et al. (2022) [24]	Italy	Obese women with PCOS	25	Before-after trial	The ketogenic diet consists of approximately 18 g of protein, 4 g of carbohydrates, and 3 to 4 g of fat	12 weeks	HOMA-IR, SHBG
Paoli et al. (2020) [25]	Italy	Overweight women with PCOS	14	Before-after trial	The ketogenic diet is characterized by high protein content, with each portion containing 19 g of protein, and very low carbohydrate content, with each portion containing 3.5 g of carbohydrates	12 weeks	Glucose, HOMA-IR, LH, FSH, total testosterone, SHBG, TG, TC, LDL, HDL
Khalid et al. (2024) [26]	Pakistan	Overweight women with PCOS	47	Before-after trial	Ketogenic mediterranean with phytoextracts diet which is very low caloric ketogenic diet (1000 kcal) + phytoextracts for first 3 weeks, low caloric KD (1200 kcal) + phytoextracts for second 3 weeks and Mediterranean diet (1600 kcal) + phytoextracts for last 6 weeks	12 weeks	Glucose, LH, FSH, TG, TC, LDL, HDL

RCT: Randomized controlled trial; PCOS: polycystic ovary syndrome; KD: ketogenic diet; HOMA-IR: Homeostatic Model Assessment; LH: Luteinizing hormone; FSH: Follicle-stimulating hormone