Results of linear regression analyses for mean energy content (kcal) of lunchtime fast food purchases in 2009, by customers’ use of information on calorie labelling
| Model 1* | Model 2* | ||||
|---|---|---|---|---|---|
| Mean (95% CI) energy content/purchase (kcal) | P value | Mean (95% CI) energy content/purchase (kcal) | P value | ||
| Estimated marginal means | |||||
| Did not use information | 862.0 (849.0 to 875.2) | — | 859.4 (851.8 to 867.0) | — | |
| Used information | 765.9 (743.0 to 788.9) | — | 781.6 (767.3 to 795.9) | — | |
| Parameter estimates | |||||
| Did not use information | Reference | — | Reference | — | |
| Used information | −96.2 (−71.8 to −120,7) | <0.001 | −77.8 (−62.3 to −93.4) | <0.001 | |
| Sex (women–men) | −95.2 (−113.6 to −76.7) | <0.001 | −46.9 (−57.3 to −36.5) | 0.08 | |
| Age (years): | |||||
| 18–24 | 98.4 (63.3 to 133.5) | <0.001 | 44.6 (27.9 to 61.3) | <0.001 | |
| 25–34 | 112.7 (89.5 to 125.9) | 27.0 (13.4 to 40.5) | |||
| 35–44 | 97.1 (71.6 to 122.6) | 26.5 (14.1 to 39.0) | |||
| ≥45 | Reference | Reference | |||
| Poverty level†: | |||||
| Of customer residence | 63.7 (−13.3 to 140.6) | 0.10 | 40.1 (6.2 to 74.1) | 0.02 | |
| Of store location | 10.4 (−63.2 to 84.1) | 0.78 | 26.1 (−16.3 to 68.6) | 0.23 | |
| Description of purchase: | |||||
| No of food items | — | — | 148.6 (130.9 to 166.4) | <0.001 | |
| Beverage (0=No; 1=Yes) | — | — | 25.2 (8.7 to 41.7) | 0.003 | |
| Cost (inflation adjusted) | — | — | 102.8 (96.4 to 109.2) | <0.001 | |
Models include city residents only (poverty level for customer residence could not be determined for non-city residents).
*Model 1 adjusted for restaurant chain, sex, and neighbourhood poverty. Model 2 further controlled for the number of food items purchased, beverage purchased, and cost. Both models included a variable for chain, to adjust for change in customer volume across the two years.
†Poverty is a continuous variable defined as the percentage of households in the store’s zip code that were below twice the national poverty level.