Significant* predictors of underweight (UW), overweight (OW) or obesity (OB) at 5 years of age from multinomial logistic regression analysis with normal weight (NW) children as reference†
| Variables Reference category | Valid n | Weight group (BMI)† | Unadjusted‡ | Adjusted model§ (n=709) | Final model¶** (n=759) | |||
| OR (95 % CI)†† | P | OR (95 % CI)†† | p | OR (95 % CI)†† | p | |||
| Age of mother at birth | 1088 | UW | 0.96 (0.92 to 1.01) | 0.005 | 0.95 (0.89 to 1.01) | 0.043 | 0.95 (0.89 to 1.01) | 0.059 |
| OW | 1.01 (0.97 to 1.05) | 1.02 (0.97 to 1.08) | 1.02 (0.96 to 1.07) | |||||
| OB | 0.89 (0.83 to 0.96) | 0.90 (0.82 to 1.00) | 0.91 (0.83 to 1.00) | |||||
| Current BMI mother | 981 | UW | 0.91 (0.84 to 0.98) | <0.001 | 0.95 (0.87 to 1.04) | 0.002 | 0.96 (0.87 to 1.05) | 0.002 |
| OW | 1.13 (1.07 to 1.18) | 1.10 (1.03 to 1.17) | 1.10 (1.04 to 1.17) | |||||
| OB | 1.19 (1.12 to 1.28) | 1.14 (1.03 to 1.25) | 1.13 (1.03 to 1.25) | |||||
| Current BMI father | 924 | UW | 0.88 (0.81 to 0.96) | <0.001 | 0.86 (0.77 to 0.96) | 0.001 | 0.86 (0.78 to 0.95) | 0.001 |
| OW | 1.12 (1.05 to 1.19) | 1.05 (0.98 to 1.14) | 1.08 (1.01 to 1.17) | |||||
| OB | 1.22 (1.12 to 1.33) | 1.14 (1.02 to 1.28) | 1.08 (0.97 to 1.20) | |||||
| Birth weight SDS | 1060 | UW | 0.73 (0.63 to 0.85) | <0.001 | 0.54 (0.35 to 0.82) | 0.003 | 0.34 (0.06 to 1.89) | 0.005 |
| OW | 0.99 (0.85 to 1.15) | 1.49 (1.01 to 2.18) | 6.38 (1.50 to 27.20) | |||||
| OB | 1.21 (0.92 to 1.59) | 0.87 (0.45 to 1.68) | 0.16 (0.02 to 1.24) | |||||
| Birth length SDS | 954 | UW | 0.80 (0.67 to 0.97) | 0.121 | 1.51 (0.99 to 2.32) | 0.071 | 1.57 (1.04 to 2.37) | 0.020 |
| OW | 0.92 (0.77 to 1.01) | 0.74 (0.50 to 1.09) | 0.68 (0.45 to 1.02) | |||||
| OB | 1.07 (0.78 to 1.47) | 1.27 (0.62 to 2.60) | 1.32 (0.73 to 3.24) | |||||
| Birth weight SDS*current BMI mother‡‡ | 961 | UW | 1.02 (0.95 to 1.09) | 0.025 | ||||
| OW | 0.95 (0.90 to 1.00) | |||||||
| OB | 1.07 (0.99 to 1.14) | |||||||
| Sex | 1088 | 0.406 | 0.540 | 0.602 | ||||
| Boys | UW | 0.99 (0.63 to 1.54) | 0.93 (0.53 to 1.65) | 0.93 (0.54 to 1.60) | ||||
| OW | 0.73 (0.49 to 1.09) | 0.72 (0.42 to 1.24) | 0.78 (0.46 to 1.33) | |||||
| OB | 0.77 (0.40 to 1.49) | 0.63 (0.25 to 1.62) | 0.61 (0.25 to 1.51) | |||||
| Girls (reference) | UW | 1 | 1 | 1 | ||||
| OW | 1 | 1 | 1 | |||||
| OB | 1 | 1 | 1 | |||||
| Siblings | 1065 | 0.09 | 0.008 | 0.002 | ||||
| No siblings | UW | 0.38 (0.12 to 1.22) | 0.32 (0.07 to 1.55) | 0.23 (0.05 to 1.08) | ||||
| OW | 1.96 (1.12 to 3.43) | 3.13 (1.40 to 6.99) | 3.13 (1.45 to 6.74) | |||||
| OB | 0.31 (0.04 to 2.28) | 0.36 (0.04 to 3.31) | 0.34 (0.04 to 3.11) | |||||
| One or more siblings (reference) | UW | 1 | 1 | 1 | ||||
| OW | 1 | 1 | 1 | |||||
| OB | 1 | 1 | 1 | |||||
| Maternal education | 1068 | <0.001 | 0.068 | 0.022 | ||||
| Maximum high school | UW | 1.14 (0.72 to 1.82) | 1.27 (0.67 to 2.40) | 1.26 (0.64 to 2.30) | ||||
| OW | 1.79 (1.21 to 2.66) | 1.60 (0.92 to 2.80) | 1.75 (1.01 to 3.01) | |||||
| OB | 5.99 (2.6 to 13.80) | 3.13 (1.05 to 9.32) | 3.54 (1.20 to 10.42) | |||||
| Above high school (reference) | UW | 1 | 1 | 1 | ||||
| OW | 1 | 1 | 1 | |||||
| OB | 1 | 1 | 1 | |||||
| Maternal smoking | 1088 | <0.001 | 0.106 | 0.018 | ||||
| Mother smoking | UW | 0.83 (0.44 to 1.56) | 0.76 (0.31 to 1.89) | 0.66 (0.28 to 1.57) | ||||
| OW | 2.39 (1.55 to 3.67) | 2.05 (1.09 to 3.84) | 2.08 (1.14 to 3.79) | |||||
| OB | 4.07 (2.09 to 7.91) | 1.74 (0.65 to 4.65) | 2.57 (1.03 to 6.42) | |||||
| Mother not smoking (reference) | UW | 1 | 1 | 1 | ||||
| OW | 1 | 1 | 1 | |||||
| OB | 1 | 1 | 1 | |||||
| Fruit | 1078 | 0.088 | 0.012 | 0.022 | ||||
| ≥5 days/week | UW | 0.94 (0.55 to 1.63) | 0.97 (0.45 to 2.08) | 0.98 (0.48 to 2.02) | ||||
| OW | 1.99 (1.09 to 3.63) | 3.35 (1.36 to 8.28) | 3.41 (1.39 to 8.38) | |||||
| OB | 0.79 (0.37 to 1.70) | 2.80 (0.71 to 9.86) | 1.64 (0.54 to 4.97) | |||||
| <5 days/week (reference) | UW | 1 | 1 | 1 | ||||
| OW | 1 | 1 | 1 | |||||
| OB | 1 | 1 | 1 | |||||
| Exclusive breast feeding | 1003 | 0.004 | 0.186 | |||||
| <4 months | UW | 0.73 (0.43 to 1.25) | 0.85 (0.43 to 1.67) | |||||
| OW | 1.49 (0.98 to 2.25) | 1.14 (0.65 to 2.00) | ||||||
| OB | 2.69 (1.35 to 5.33) | 2.72 (1.06 to 7.00) | ||||||
| ≥4 months (reference) | UW | 1 | 1 | |||||
| OW | 1 | 1 | ||||||
| OB | 1 | 1 | ||||||
| Caretakers | 1073 | 0.014 | 0.392 | |||||
| Living with one caretaker | UW | 0.79 (0.37 to 1.69) | 0.69 (0.19 to 2.55) | |||||
| OW | 1.56 (0.92 to 2.63) | 1.22 (0.50 to 2.97) | ||||||
| OB | 3.10 (1.48 to 6.46) | 2.99 (0.83 to 10.78) | ||||||
| Living with two caretakers (reference) | UW | 1 | 1 | |||||
| OW | 1 | 1 | ||||||
| OB | 1 | 1 | ||||||
*Exposure variables (table 2a-c) that did not remain significant in this model are not included.
†Definitions of weight class according to International Obesity Task Force age-specific and sex-specific cut-off values.
‡Bivariate multinomial logistic regression.
§Adjusted model created through an all-in backward stepwise selection procedure.
¶The final model was created from the adjusted model by including the significant interaction between birth weight SDS and maternal BMI, and excluding two variables from the adjusted model: breastfeeding due to high number of missing (and p>0.1 in the adjusted model) and living with two caretakers due to p>0.1.
**Explained variance of the final model=0.13 (McFadden’s pseudo-R-squared).
††Odds of being in the respective BMI category group compared with reference category (NW) for categorical variables, and per unit increase in continuous variables.
‡‡Interaction between birth weight SDS and current BMI mother.
BMI, body mass index; OB, obese; OW, overweight; SDS, SD score; UW, underweight.