Table 1 Characteristic of trials that investigated the effect of low-fat versus high-fat diets on serum level of adipokines in adults that were eligible for inclusion in the meta-analysis

Arvidsson, 2004/ Europe [10]

F [35.1/ 35.3]

Healthy obese [20/ 20]

P/ 10

60–65

15–20

20–25

40–45

15–20

40–45

Yes (Deficit of 500 kcal/d of TEE)/Yes

Adiponectin, Leptin,

Bradley, 2009/ UK [49]

B [40.5/ 37.1]

Healthy obese [12/ 12]

P/ 8

60

20

20

20

20

60

Yes (Deficit of 500 kcal/d of TEE)/No

Leptin,

Brehm, 2003/ US [50]

F [43.1/ 44.2]

Healthy obese [20/ 22]

P/ 24

55

15

30

-

-

> 31

Yes (Not mentioned)/No

Leptin,

Cardillo, 2006/ US [18]

B [55/ 54]

Healthy obese

[26/ 27]

P/ 144

47

20

< 30

51

17

32

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin, Leptin

Cornier, 2005/ Sweden [11]

F [36.8/ 43.6]

Healthy obese [4/5]

P/16

60

20

20

40

20

40

Yes (Deficit of 400 kcal/d of TEE)/No

Leptin,

de Luis, 2008/ Spain [19]

B [46.5/ 46.5]

Healthy obese [99/105]

P/ 8

52

20

27

38

26

36

Yes (Not mentioned)/ Yes

Adiponectin, Leptin, Resistin

de Luis, 2012/ Spain [20]

B [43.3/ 43.3]

Healthy obese [158/ 147]

P/ 12

53

20

27

38

26

36

Yes (Not mentioned)/ Yes

Adiponectin, Leptin, Resistin

de Luis, 2016/ Spain [21]

B [52.9/ 52.9]

Healthy obese

[194/ 198]

P/ 36

52.5

18.4

29.1

30.9

36.3

32.8

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin, Leptin, Resistin

Due, 2008/ Denmark [22]

B [28.2/ 27.8]

Healthy obese [18/ 28]

P/24

60

15

25

45

15

40

No/ No

Adiponectin,

50

15

35

Ebbeling, 2012/ US [51]

B [30.3/ 30.3]

Healthy obese [21/ 42]

C/ 4

60

20

20

40

20

40

No/ No

Leptin,

10

30

60

Fava, 2013/ Italy [52]

B [30/ 58]

Metabolic syndrome [38/ 50]

P/ 24

55

28

45

38

No/ No

Leptin,

Frisch, 2009/ Germany [23]

B [47/ 47]

Healthy obese [100/ 100]

P/ 48

> 55

15

< 30

< 40

25

> 35

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin,

Gepner, 2017/ Israel [53]

B [48.4/ 47.4]

Metabolic obese [118/ 122]

P/ 72

30

> 35

No/ Yes (each diet group was further randomized into added PA groups (LF^PA+, MED/LC^PA+) or no added PA groups)

Leptin,

Goldenshluger, 2021/ Isreal [24]

B [48.4/ 47.4]

Metabolic obese [79/ 80]

P/ 24

30

> 35

No/ Yes (each diet group was further randomized into added PA groups (LF^PA+, MED/LC^PA+) or no added PA groups)

Adiponectin,

Haufe, 2011/ Germany [25]

B [45/ 43.5]

Healthy obese [50/ 52]

P/ 24

0.8 gr/kg

≤ 20

≤ 90 gr/dy

0.8 gr/kg

≥ 30

Yes (Deficit of 30% energy intake)/No

Adiponectin, Leptin

Heggen, 2012/ Norway [26]

B [49.8/ 50.3]

Metabolic obese [88/ 93]

P/ 12

55–60

15

< 30

30–35

25–30

35–40

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin, Leptin, Resistin

Hu, 2015/ US [27]

B [47.8/ 45.8]

Healthy obese [73/ 75]

P/ 48

30

< 40gr

No/Yes

Adiponectin, Leptin, Resistin

Iqbal, 2005/ US [62]

B [54/ 55]

Healthy obese

[32/ 39]

P/ 26

< 30

> 30

Yes (Deficit of 500 kcal/d of TEE)/No

Resistin

Izadi, 2018/ Iran [28]

B [42.4/ 41]

Healthy normal weight [60/ 30]

P/ 12

58

15

26

54

15

31

No/ No

Adiponectin, Leptin

59

15

25

Juanola-Falgarona, 2013/ US [29]

B [44.1/ 43.2]

Healthy obese

[40/ 81]

P/ 24

51.4

31.4

17.2

41.8

18.6

39.6

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin, Leptin

42.2

18.6

40.2

Keogh, 2008/ Australia [30]

B [49.4/ 50.5]

Healthy obese [47/ 52]

P/ 8

46

24

30

4

35

61

Yes (Deficit of 30% energy intake)/No

Adiponectin,

Komiyama, 2003/ Japan [54]

B [55.6/ 55.6]

Diabetes and with or without impaired glucose tolerance [53/ 53]

C/ 4

70

15

15

55

15

30

No/ No

Leptin,

Lovejoy, 2003/ US [55]

M [36.7/ 36.7]

Healthy obese [30/ 15]

P/ 36

58

17

25

52

15

33

No/ No

Leptin,

Maiorino, 2016/ Italy [31]

B [51.9/ 52.4]

Diabetes[107/ 108]

P/ 416

<30

< 50

>30

No/ Yes

Adiponectin,

Mayr, 2019/ Australia [32]

B [61.8/ 61.8]

Healthy obese [31/ 34]

P/ 26

45–65

15–25

< 30

35

15

42

No/ No

Adiponectin,

Miller, 2008/ US [56]

F [39.4/ 39.4]

Healthy obese [12/ 13]

P/ 12

60

15

25

60 g /day

No/ No

Leptin,

Mohammadi Zadeh, 2018/ Iran [17]

M [49.3/ 45.5]

Diabetes and obese [11/ 31]

P/ 24

50

20

30

50

15

35

No/ No

Adiponectin, Leptin, Resistin

20

35

45

30

10

60

Petrisko, 2020/ US [57]

B [43.2/ 43.2]

Healthy obese [17/ 34]

C/ 4

61

18

21

10

40

50

Yes (Not mentioned)/ No

Leptin,

10

30

60

Pieke, 2000/ Germany [58]

M [39.2/ 39.2]

Dyslipidemia [19/ 19]

C/ 6

54

18.2

28

40.5

19.8

39

No/ No

Leptin,

Rajaie, 2013/ Iran [34]

F [42.4/ 42.4]

Metabolic syndrome and obese [30/ 30]

C/ 6

60–65

15–17

20–25

43–47

15–17

36–40

Yes (Deficit of 350–750 kcal/d of TEE)/No

Adiponectin, Leptin,

Reddy, 2023/ Australia [35]

B [52.1/ 52.6]

Metabolic obese [19/ 18]

P/ 12

50

20

30

33

15–20

44

No/ No

Adiponectin, Leptin, Resistin

Rolland, 2011/ UK [37]

B [41.9/ 45.8]

Healthy obese [14/ 17]

P/ 36

36

36

28

20

40

40

Yes (Deficit of 600 kcal/d of TEE)/No

Adiponectin, Leptin, Resistin

Ruth, 2013/ US [38]

B [41.5/ 43.5]

Healthy obese [15/ 18]

P/ 12

60

15

25

< 40gr

35

60

Yes (Deficit of 500 kcal/d of TEE)/No

Adiponectin,

Salwa, 2012/ France [36]

B [45/ 45]

Healthy obese [13/ 13]

C/ 4

40

35

25

44

25

31

Yes (Deficit of 30% energy intake)/No

Adiponectin, Leptin

Saris, 2000/ Europe countries* [59]

B [39.5/ 38]

Healthy obese [159/ 77]

P/ 24

10

32

No/ No

Leptin,

Shai, 2008/ Israel [39]

B [51/ 52.5]

Healthy obese [104/ 218]

P/ 96

50.7

19

30

40.4

21.8

39.1

Yes (Not mentioned)/ No

Adiponectin, Leptin,

50.2

18.8

33.1

Song, 2016/ US [40]

B [36.6/ 36.1]

Normal weight [62/ 30]

P/ 6

64

18

18

46

18

36

Yes (Deficit of 33% energy intake)/No

Adiponectin, Leptin,

Strath, 2019/ US [60]

B [72.3/ 69.2]

Knee osteoarthritis [6/ 15]

P/ 12

60

20

20

≤ 20 gr/d

Unlimited

Yes (Deficit of 500 kcal/ day in male and 250–300 kcal/day in female)/ No

Leptin,

Unlimited

Tabesh, 2013/ Iran [41]

F [50/ 50.4]

Metabolic obese [34/ 19]

P/ 8

64.8

12.92

25.5

55.1

13.5

33.2

Yes (Deficit of 200 to 500 kcal/ day)/ No

Adiponectin, Leptin

57.1

16.2

< 30

Theodore, 2007/ Australia [33]

M [Middle age]

Healthy obese [20/ 15]

P/ 16

55

20

25

40

20

35

Yes (Not mentioned)/ No

Adiponectin, Leptin

Tierney, 2011/ 8 European counties [42]

B [55.4/ 54.6]

Metabolic syndrome [206/ 211]

P/ 12

28

38

No/ No

Adiponectin, Leptin, Resistin

28

38

Varady, 2011/ US [43]

B [36/ 35]

Healthy obese [8/ 9]

P/ 6

55

20

25

5

35

60

Yes (Deficit of 25% energy intake)/No

Adiponectin, Leptin, Resistin

Vetter, 2010/ US [44]

B [58.6/ 60.8]

Diabetes and obese [42/ 37]

P/ 24

≤30

< 30gr

Yes (Deficit of 500 kcal/ day)/ No

Adiponectin, Leptin,

von Frankenberg, 2017/ US [45]

B [18–55]

Healthy obese [10/ 10]

C/ 4

62

18

20

27

18

55

No/ No

Adiponectin,

Volek, 2009/ US [61]

B [36.9/ 32.6]

Metabolic obese [20/ 20]

P/ 12

56

20

24

12

28

59

Yes (Deficit of 500 kcal/ day)/ No

Leptin,

Wan, 2017/ China [46]

B [23.4/ 23.5]

Healthy [101/ 206]

P/ 24

66

14

20

56

14

30

No/ No

Adiponectin, Leptin

46

14

40

Wycherley, 2010/ Australia [47]

B [50.2/ 49.9]

Healthy obese [23/ 26]

P/ 52

46

24

30

4

35

61

Yes (Not mentioned)/ No

Adiponectin

Youssef, 2015/ Saudi Arabia [48]

F [20–22]

Healthy obese [6/ 12]

P/ 6

55

30

15

30

30

40

Yes (Not mentioned)/ No

Adiponectin,

60

15

25