Final multivariable regression of the association and interaction between diet patterns in white and non-whites with birth weight (g)
| Variables | Model 1 | Model 2 | ||
| β | P value | β | P value | |
| Intercept | −4551.9 | <0.001 | −4560.8 | <0.0001 |
| Prepregnancy weight (kg) | 5.5 | <0.001 | 5.4 | <0.001 |
| Maternal height (cm) | 8.4 | <0.001 | 8.5 | <0.001 |
| Parity (number of children) | 67.6 | <0.001 | 66.0 | <0.001 |
| Gestational age (weeks) | 158.4 | <0.001 | 158.2 | <0.001 |
| Smoking status | −21.9 | 0.04 | −23.6 | 0.02 |
| Infant sex (female=1) | −118.6 | <0.001 | −118.8 | <0.001 |
| Non-white ethnicity | −33.5 | 0.04 | −28.1 | 0.08 |
| Plant-based diet | −34.6 | <0.001 | −67.6 | <0.001 |
| Western diet | −12.7 | 0.35 | ns | ns |
| Health-conscious diet | 6.0 | 0.56 | ns | ns |
| Plant-based diet × non-white | NA | NA | 40.5 | 0.03 |
Model 1 included all covariates, non-White ethnicity indicator, three diet patterns identified using PCA: plant-based, Western and health-conscious diet. Model 2 tests interactions between non-white ethnicity and significant diet patterns after removal of non-significant variables from model 1 (n=3997). Non-significant variables removed from the model are denoted as ‘ns’. Smoking status was ordinal and input as either 0=never smoked, 1=quit smoking prepregnancy, 2=quit smoking during pregnancy or 3=currently smoking. Parity was ordinal and reported as having 0, 1, 2, 3, 4, 5 or 6 (or more) children. Non-whites included individuals who self-reported as being of South Asian, East/South-East Asian or Aboriginal descent.
NA, not applicable; PCA, principal component analysis.