Table 4 Multiple linear regression analysis for students’ exam scores (n = 608, R² = 12.8%, Max. VIF = 4.898)

Covariates

Residency type (Dormitory)

 Rented house

-0.782

0.839

-0.056

0.352

-2.429

0.866

 Owned house

0.114

0.852

0.010

0.893

-1.558

1.787

Residency partners (Alone)

 Friends/Roommates

0.380

1.133

0.025

0.738

-1.846

2.606

 Relatives

1.122

1.764

0.029

0.525

-2.343

4.587

 Brothers/Sisters

1.385

1.318

0.060

0.294

-1.203

3.974

 Family

1.426

1.034

0.118

0.168

-0.605

3.456

Sex (Female)

0.646

0.462

0.059

0.162

-0.261

1.553

Age

-0.759

0.148

-0.203

 < 0.001*

-1.049

-0.468

Variables of interest

 Cigarettes

0.168

0.241

0.031

0.486

-0.305

0.641

 Water pipe

-0.700

0.354

-0.080

0.049*

-1.396

-0.005

 Traditional coffee

-0.033

0.159

-0.009

0.836

-0.346

0.280

 Tea

-0.334

0.145

-0.095

0.022*

-0.618

-0.049

 Instant coffee

-0.682

0.212

-0.142

0.001*

-1.099

-0.265

 Mate

0.109

0.140

0.033

0.437

-0.166

0.384

 Energy drink

-0.283

0.965

-0.012

0.770

-2.178

1.613

 Natural fruit juice

-0.407

0.371

-0.045

0.273

-1.137

0.322

 Fruit

0.122

0.232

0.022

0.600

-0.334

0.577

 Vitamin C

0.033

0.326

0.004

0.920

-0.608

0.674

 Alcohol

0.966

0.493

0.079

0.051

-0.004

1.935

Scheduled eating (No)

-0.613

0.469

-0.055

0.192

-1.534

0.309

 Breakfast

0.074

0.101

0.032

0.465

-0.124

0.271

 Fast food

-0.583

0.280

-0.092

0.038*

-1.132

-0.034

 Snacks

0.027

0.208

0.005

0.897

-0.382

0.436