Table 2 Summary results of the effect of caffeine in the interventional group compared with the control group

Obesity

Food Intake

-

5 studies [15, 19, 20, 22, 29]

2 studies [8, 24] + HSDM [4]

2 studies [14, 25] + HFDM [4]

10

Energy Intake

-

1 study [29]

1 study [24]

1 study [21]

3

Final Weight

1 study [18]

8 studies

[8, 19,20,21,22, 24, 26, 29]

1 study [25]

1 study [23]

11

Change in Body Weight

1 study [27]

1 study [15] + HFDM [4]

-

HSDM [4]

3

Body Fat Percentage

-

2 studies [26, 29]

-

-

2

Whole-body Fat Weight

-

2 studies [24, 26]

-

-

2

Whole-body White Adipose Tissue Weight

-

1 study [29]

-

-

1

Body Fat-pad Weight

-

3 studies [21, 24, 29] + HFDM [4]

-

HSDM [4]

4

Dyslipidemia

Serum Triglycerides

1 study [24]

3 studies [26, 28, 29]

-

5 studies [15, 19, 20, 22, 25]

9

Serum Total Cholesterol

5 studies [15, 19, 20, 22, 24]

2 studies [26, 28]

-

3 studies [25, 27, 29]

10

LDL-C

-

3 studies [25, 26, 29]

1 study [27]

-

4

HDL-C

2 studies [15, 28]

-

1 study [29]

3 studies [25,26,27]

6

Serum Non-esterified Fatty Acids

1 study [24]

2 studies [8, 29] + HSDM [4]

-

HFDM [4]

4

Hepatic Steatosis

Liver Triglycerides

-

1 study [15]

-

-

1

Liver Cholesterol

-

-

1 study [15]

-

1

Liver Weight

-

-

2 studies [15, 24] + Naidoo and Islam [25]

Naidoo and Islam [25]

3

Hepatic Dysfunction

Serum AST

-

2 studies [24, 28]

-

3 studies [25, 27, 29]

5

Serum ALT

-

3 studies [24, 28, 29]

1 study [27]

1 study [25]

5

Serum AP

1 study [24]

Naidoo and Islam [25]

-

Naidoo and Islam [25]

2

Serum LDH

-

1 study [24]

-

1 study [25]

2

Serum Albumin

Helal, Ayoub [28]

-

Helal, Ayoub [28]

1 study [24]

2

Serum Total Bilirubin

-

2 studies [24, 28]

-

-

2

Insulin Resistance

Serum Fasting Glucose

-

4 studies [8, 20, 24, 25] + HSDM [4] + Kagami, Morita [23]

2 studies [22, 27]

1 study [21] + HFDM [4] + Kagami, Morita [23]

9

Serum Postprandial Glucose

-

1 study [19]

-

1 study [25]

2

Area Under the Glucose Curve

-

2 studies [22, 24]

-

1 study [19]

3

Serum Fasting Insulin

1 study [25]

3 studies [8, 19, 20] + HFDM [4]

1 study [24] + Kagami, Morita [23]

2 studies [21, 22] + HSDM [4] + Kagami, Morita [23]

8

Serum Postprandial Insulin

-

1 study [19]

-

-

1

Area Under the Insulin Curve

-

1 study [19]

-

-

1

Fluid Intake

-

3 studies [19, 20, 22]

3 studies [18, 21, 24] + HFDM [4]

2 studies [14, 25] + HSDM [4]

9

Urinary Volume

1 study [8]

4 studies [14, 19, 20, 22]

-

-

5

Urinary Glucose

-

3 studies [19, 20, 22]

-

-

3

OGTT Initial

-

4 studies [20, 22, 24, 25] + Kagami, Morita [23]

-

Kagami, Morita [23]

5

OGTT-30 min

-

Kagami, Morita [23]

1 study [20]

3 studies [22, 24, 25] + Kagami, Morita [23]

5

OGTT-60 min

-

1 study [23]

-

4 studies [20, 22, 24, 25]

5

OGTT-90 min

-

Naidoo and Islam [25]

-

Naidoo and Islam [25]

1

OGTT-120 min

-

3 studies [20, 22, 24] + Naidoo and Islam [25]

-

Naidoo and Islam [25]

4

ITT Initial

-

-

-

1 study [24]

1

ITT-30 min

-

-

-

1 study [24]

1

ITT-60 min

-

-

-

1 study [24]

1

ITT-120 min

-

1 study [24]

-

-

1

Hypertension

Systolic Blood Pressure

1 study [20]

3 studies [8, 16, 24]

1 study [19]

2 studies [14, 17]

7

Diastolic Blood Pressure

1 study [20]

1 study [8]

1 study [19]

1 study [17]

4

Mean Arterial Blood pressure

2 studies [18, 20]

HFDM [4] + HSDM [4]

2 studies [19, 22]

1 study [17]

6