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Table 1 Characteristics of the included studies

From: Intermittent versus continuous energy restriction on weight loss and cardiometabolic outcomes: a systematic review and meta-analysis of randomized controlled trials

Author

(year)

[ref]

Study design

Participants

Trial duration

N

Study groups

Age (years)

Males (n)

BMI (kg/m2)

Waist-c (cm)

FM

FFM (kg)

SBP

DBP (mmHg)

Fasting glucose (mg/dL)

Hb1Ac (%)

Fasting insulin (µU/mL)

HOMA-IR (mmol/L * µU/mL)

Total chol (mg/dL)

HDL-c (mg/dL)

LDL-c (mg/dL)

TG (mg/dL)

Antoni

(2018)

[22]

RCT 2 parallel arms

BMI > 25 kg/m2

Age 18–65 years

No comorbidity

8–10 weeks

15a

IER (2 days/week) = 25% of the energy need on 2 consecutive fast days and energy according to needs on feed days

42 ± 4

7

30 ± 1

31 ± 2

123 ± 3

79 ± 2

11 ± 1

162 ± 12

42 ± 4

100 ± 12

97 ± 9

102 ± 3

58 ± 3

74 ± 3

ND

1.6 ± 0.2

    

12a

CER: 600 kcal less than estimated needs

48 ± 3

6

31 ± 1

34 ± 3

115 ± 3

79 ± 4

9 ± 1

162 ± 12

39 ± 4

104 ± 8

80 ± 9

102 ± 2

56 ± 3

75 ± 3

ND

1.3 ± 0.1

    

Carter

(2016)

[24]

RCT 2 parallel arms

T2DM

BMI ≥ 27 kg/m2

Age ≥ 18 years

No comorbidity

12 weeks

31

IER (2 days/week) = 400–600 kcal/day on fast days and no restriction on feed days

61 ± 8

16

35 ± 5

38 ± 9

134 ± 17

ND

ND

ND

ND

ND

ND

ND

55 ± 11

84 ± 10

7 ± 1

     

32

CER = 1200–1500 kcal/day every day

62 ± 9

14

36 ± 5

40 ± 11

138 ± 15

ND

ND

ND

ND

ND

ND

ND

54 ± 9

90 ± 11

8 ± 1

     

Catenacci

(2016)

[27]

RCT 2 parallel arms

BMI ≥ 30 kg/m2

Age 18–55 years

Non-smokers

No diabetes, CV diseases, major comorbidity

8 weeks

15

IER (3 days/week) = 0 kcal/day on fast days alternate and energy according to needs, but with the chance to ask for more food, on feed days

40 ± 10

3

36 ± 4

38 ± 8

ND

88 ± 7

13 ± 6

170 ± 33

38 ± 8

100 ± 31

143 ± 56

ND

53 ± 9

 

ND

ND

    

14

CER = 400 kcal less than needs

43 ± 8

3

40 ± 6

49 ± 10

ND

92 ± 8

19 ± 6

171 ± 36

39 ± 7

104 ± 29

140 ± 43

ND

61 ± 12

 

ND

ND

    

Conley

(2018)

[23]

RCT 2 parallel arms

Men with BMI ≥ 30 kg/m2

Age 55–75 years

No diabetes

No high alcohol intake or major comorbidity

24 weeks

12

IER (2 days/week) = 600 kcal/day on 2 non-consecutive fast days and energy ad libitum on feed days

68 ± 3

12

33 ± 2

ND

142 ± 14

108 ± 27

ND

151 ± 35

45 ± 12

77 ± 31

168 ± 53

114 ± 5

 

84 ± 10

ND

12

CER = 500 kcal less than needs

67 ± 4

12

36 ± 4

ND

150 ± 18

110 ± 31

ND

166 ± 39

46 ± 12

98 ± 35

212 ± 150

123 ± 10

 

88 ± 14

ND

Coutinho

(2017)

[28]

RCT 2 parallel arms

BMI = 30–40 kg/m2

Age 18–65 years

Inactive, no menopause or major comorbidity

12 weeks

18

IER (3 days/week) = 550–660 kcal/day on fast days and energy according to needs on feed days

39 ± 11

4

36 ± 3

47 ± 8

ND

ND

ND

ND

ND

ND

ND

ND

60 ± 12

17

CER = 33% of energy restriction every day

39 ± 9

2

35 ± 4

43 ± 8

ND

ND

ND

ND

ND

ND

ND

ND

55 ± 9

Harvie

(2011)

[26]

RCT 2 parallel arms

BMI = 24–40 kg/m2

Premenopausal women

Age 30–45 years

Non-smokers, not using OC, no major comorbidity

24 weeks

53

IER (2 days/week) = 25% of the energy need on 2 consecutive fast days and energy according to needs on feed days

40 ± 4

0

31 ± 5

34 (31–36)

115 (111–119)

87 (85–88)

7 (6–8)

197 (189–197)

58 (54–58)

119 (112–127)

106 (88–124)

102 (98–105)

48 (46–49)

77 (74–79)

ND

1.5 (1.3–1.8)

    

54

CER = 25% energy restriction every day

40 ± 4

0

31 ± 5

35 (32–39)

117 (113–120)

87 (83–88)

7 (6–9)

200 (193–208)

62 (54–66)

119 (108–127)

115 (97–124)

102 (99–106)

49 (48–50)

75 (72–78)

ND

1.6 (1.3–1.8)

Harvie

(2013)

[20]

RCT 3 parallel arms

Women with BMI = 24–45 kg/m2 or body fat > 30% of BW

Age 30–45 years

No major comorbidity

12 weeks

37

IER (2 days/week) = 25% of the energy need on 2 consecutive fast days and energy according to needs on feed days

46 ± 8

0

30 ± 4

31 (28–34)

115 (111–125)

88 (85–90)

6 (5–8)

204 (191–229)

50 (49–59)

128 (116–139)

088 (75–102)

101 (97–104)

48.5 (46–50)

ND

5

1.6 (1.3–1.9)

 

38

IER as above plus unlimited proteins and fats (non-SFA) on fast days

49 ± 7

0

31 ± 6

34 (30–37)

130 (115–138)

90 (86–92)

7 (6–9)

221 (206–237)

55 (51–59)

144 (130–159)

95 (81–109)

104 (99–109)

49 (47–51)

ND

6

1.9 (1.5–2.2)

40

CER = daily 25% restriction every day

48 ± 8

0

32 ± 6

36 (32–39)

124 (116–131)

90 (86–92)

7 (6–9)

205 (193–218)

51 (48–55)

129 (118–139)

97 (83–111)

106 (102–110)

50 (48–52)

ND

6

1.8 (1.5–2.2)

Sundfor

(2018)

[21]

RCT 2 parallel arms

BMI = 30–45 kg/m2

Age 21–70 years

Waist ≥ 84/90 cm (male/female) plus another component of the metabolic syndrome

No comorbidity or alcohol/drug

abuse

24 weeks

54

IER (2 days/week) = 400–600 kcal/day on 2 non-consecutive fast days and energy as usual on feed days

50 ± 10

28

35 ± 4

ND

129 ± 13

104 ± 22

ND

192 ± 35

47 ± 13

126 ± 32

162 ± 73

116 ± 10

 

88 ± 8

6 ± 1

58

CER = 400–600 kcal less than needs

48 ± 12

28

35 ± 4

ND

128 ± 13

103 ± 13

ND

197 ± 34

45 ± 10

133 ± 32

137 ± 60

116 ± 10

 

86 ± 9

6 ± 1

Trepanowski

(2017)

[17]

RCT 3 parallel arms

BMI = 25.0–39.9 kg/m2

Age 18–65 years

Non-smokers, inactive

No menopause, diabetes, CV diseases

24 weeks

34

IER (alternate d/week) = 25% of the energy need on fast days and 125% of energy needs on feed days

44 ± 10

4

34 ± 4

38 ± 7

124 ± 12

90 ± 12

16 ± 14

188 ± 35

57 ± 14

111 ± 13

101 ± 59

ND

55 ± 9

83 ± 9

ND

ND

35

CER = daily 25% restriction every day

43 ± 12

6

35 ± 4

40 ± 7

122 ± 17

92 ± 18

20 ± 18

184 ± 35

53 ± 11

112 ± 31

97 ± 27

ND

58 ± 12

80 ± 11

ND

ND

31

C = no dietary intervention

44 ± 11

4

34 ± 4

36 ± 10

121 ± 16

87 ± 8

16 ± 9

190 ± 30

59 ± 13

112 ± 31

98 ± 43

ND

53 ± 10

81 ± 11

ND

ND

Varady

(2011)

[19]

RCT 4 parallel arms

BMI = 25–39.9 kg/m2

Age 35–65 years

Non-smokers, inactive

No diabetes, CV diseases

12 weeks

15

IER (3 days/week) = 25% of the energy need on fast days and ad libitum on feed days

47 ± 2

3

32 ± 2

ND

ND

ND

ND

ND

ND

51 ± 3

141 ± 9

ND

15

CER = 25% energy restriction every day

47 ± 3

2

32 ± 2

ND

ND

ND

ND

ND

ND

60 ± 6

137 ± 9

ND

15

Moderate exercise program, no diet intervention

46 ± 3

2

33 ± 1

ND

ND

ND

ND

ND

ND

51 ± 4

122 ± 9

ND

15

C = no dietary/exercise intervention

46 ± 3

2

32 ± 2

ND

ND

ND

ND

ND

ND

57 ± 3

136 ± 10

ND

Williams

(1998)

[25]

RCT, 3 parallel

Arms

T2DM

Age 30–70 years

BW > 20% ideal

Not currently on insulin, no liver, renal, heart diseases

20 weeks

18

IER (1 day/week) = 400–600 kcal/day on fast day and 1500–1800 kcal/day on feed days

51 ± 8

9

35 ± 5

ND

ND

177 ± 56

20 ± 11

215 ± 37

41 ± 8

132 ± 35

197 ± 83

ND

  

8 ± 2

ND

18

IER (5 days/week) = 400–600 kcal/day on fast day every 5 weeks and 1500–1800 kcal/day on feed days

50 ± 9

7

37 ± 5

ND

ND

182 ± 58

17 ± 7

208 ± 39

42 ± 7

131 ± 29

203 ± 239

ND

  

8 ± 2

ND

18

CER = 1500–1800 kcal/day every day

54 ± 7

7

35 ± 5

ND

ND

184 ± 61

22 ± 9

218 ± 42

46 ± 11

127 ± 48

167 ± 89

ND

  

8 ± 2

ND

  1. BMI body mass index, BW body weight, Chol cholesterol, CV cardiovascular, CER continuous energy restriction, DBP diastolic blood pressure, FFM fat free mass, FM fat mass, IER intermittent energy restriction, HDL-c high density lipoprotein-cholesterol, LDL-c low density lipoprotein-cholesterol, ND no data, OC oral contraceptives, RCT randomized controlled trial, SFA saturated fatty acids, SBP systolic blood pressure, TG triglycerides, T2DM type 2 diabetes mellitus, Waist-c waist circumference, Wk week
  2. aNot available the baseline data of all the randomized patients; the study reported the baseline characteristics of the study completers only