Table 3:
Relative and absolute change for the associations between year, COVID-19 pandemic period, and BMI categories from weighted unadjusted and adjusted regression models for adults from the Canadian Community Health Survey from 2009 to 2023
| Model | Underweight | Normal weight | Overweight | Obesity |
|---|---|---|---|---|
| Relative change, OR (95% CI) | ||||
| Unadjusted | ||||
| Prepandemic annual change (per yr) | 1.02 (1.01 to 1.03) | 0.98 (0.98 to 0.98) | 1.00 (0.99 to 1.00) | 1.02 (1.02 to 1.03) |
| Excess change postpandemic onset (COVID-19 × trend)* | 1.00 (0.94 to 1.06) | 0.98 (0.97 to 1.00) | 1.00 (0.98 to 1.01) | 1.02 (1.00 to 1.03) |
| Adjusted† | ||||
| Prepandemic annual change (per yr) | 1.03 (1.01 to 1.04) | 0.98 (0.97 to 0.98) | 0.99 (0.99 to 0.99) | 1.03 (1.03 to 1.03) |
| Excess change postpandemic onset (COVID-19 × trend)* | 0.97 (0.92 to 1.04) | 0.98 (0.97 to 1.00) | 1.00 (0.99 to 1.01) | 1.02 (1.01 to 1.04) |
| Absolute change, % (95% CI) | ||||
| Unadjusted | ||||
| Prepandemic annual change (per yr) | 0.03 (0.01 to 0.05) | −0.42 (−0.48 to −0.35) | −0.08 (−0.15 to −0.01) | 0.47 (0.41 to 0.53) |
| Excess change postpandemic onset (COVID-19 × trend)* | 0.00 (−0.08 to 0.09) | −0.31 (−0.60 to −0.02) | −0.11 (−0.42 to 0.19) | 0.42 (0.13 to 0.71) |
| Adjusted† | ||||
| Prepandemic annual change (per yr) | 0.04 (0.02 to 0.06) | −0.45 (−0.52 to −0.39) | −0.20 (−0.26 to −0.13) | 0.61 (0.55 to 0.67) |
| Excess change postpandemic onset (COVID-19 × trend)* | −0.07 (−0.16 to 0.02) | −0.34 (−0.64 to −0.05) | −0.02 (−0.35 to 0.30) | 0.44 (0.14 to 0.74) |
Note: BMI = body mass index, CI = confidence interval, OR = odds ratio.
Interaction between COVID-19 pandemic indicator variable (1 = after March 2020; 0 = March 2020 and before) and linear trend (In the trend, year of survey is the unit ofchange, e.g., −11 = 2009, −5 = 2016, 0 = 2020, 3 = 2022). The effect estimate can be interpreted as the average relative odds in annual increase postpandemic. Our preferredmodel had a slope change at the start of the COVID-19 period, with no intercept shift. However, we also modelled an intercept shift (Appendix 1, Supplemental Table 14). These results were similar. Employing both slope and intercept changes was not feasible with only 3 years of data after 2020.
Adjusted for age, race or ethnicity, province, income quintile, education, and sex.