Table 1 Overview of the most relevant parameters and their interpretation
Parameter | Description | Interpretation |
|---|---|---|
Zero part | ||
 β00 | overall intercept | mean of the log-odds of no eating across all participants when all predictors are equal to 0 |
 β01 | fixed effect of L1predictor | expected change in log-odds of no eating for a one-unit increase in L1predictor |
 β02 | fixed effect of L2predictor | expected change in log-odds of no eating for a one-unit increase in L2predictor |
 u01j | random effect of L1predictor in person j | person-specific differences in the effect of L1predictor on the log-odds of no eating |
 u0j | random intercept of person j | person-specific differences in the log-odds of no eating |
 \(\sqrt{{{\sigma }^{2}}_{{u}_{0}}}\) | standard deviation of the random intercept u0 | variation of between-person differences in the log-odds of no eating |
 \(\sqrt{{{\sigma }^{2}}_{{u}_{01}}}\) | standard deviation of the random effect u01 | variation of between-person differences in the effect of L1predictor on the log-odds of no eating |
Continuous part | ||
 β10 | overall intercept | mean of the (log) amount consumed across all participants when all predictors are equal to 0 given that dietary intake occurred |
 β11 | fixed effect of L1predictor | expected change in the (log) amount consumed for a one-unit increase in L1predictor |
 β12 | fixed effect of L2predictor | expected change in the (log) amount consumed for a one-unit increase in L2predictor |
 u11j | random effect of L1predictor in person j | person-specific differences in the effects of L1predictor on the (log) amount consumed |
 u1j | random intercept of person j | person-specific differences in the (log) amount consumed |
 \(\sqrt{{{\sigma }^{2}}_{{u}_{1}}}\) | standard deviation of the random intercept u1 | variation of between-person differences in the expected (log) amount consumed |
 \(\sqrt{{{\sigma }^{2}}_{{u}_{11}}}\) | standard deviation of the random effect u11 | variation of between-person differences in the effect of L1predictor on the expected (log) amount consumed |
Cross-part correlation | ||
 \({\rho }_{{u}_{0}{u}_{1}}\) | correlation between the random intercepts u0 and u1 of the zero and continuous part | correlation between the person-specific differences in the log-odds of no eating and the person-specific difference in the (log) amount consumed |