Multiple linear regression analysis (dependent variable: increase of body mass index after 2 years)
| Variable | β | 95% CI | p Value | |
| Lower limit | Upper limit | |||
| Constant | 1.721 | 1.379 | −2.063 | <0.001 |
| Intervention | −0.962 | −1.342 | −0.582 | <0.001 |
| Eats at school | −0.419 | −0.790 | −0.049 | 0.027 |
| Obese mother | 0.990 | 0.121 | 1.859 | 0.026 |
| School | −0.004 | −0.039 | 0.031 | 0.814 |
The final model (adjusted by school) was developed from an initial model saturated with the following variables: ‘eats at school (visit 2)’, ‘obese mother’, ‘obese father’, ‘father's level of education’, ‘mother's level of education’, ‘immigrant’, ‘more than 1 h of television per day’. All variables reported in 152 school children in control and 199 in intervention group.