Dietary gluten avoidance in Canada: a cross-sectional study using survey data

Article Figures & Tables

Table 1:

Demographic characteristics of respondents who avoid dietary gluten based on results from the Canadian Community Health Survey — Nutrition, 2015

Characteristic	Dietary gluten avoidance, % ± SE	Adjusted OR (95% CI)
Sex
Male, n = 9744	1.3 ± 0.2	Reference
Female, n = 10 733	2.5 ± 0.3	2.08 (1.32 to 3.27)
Age, yr
2–17, n = 5839	0.9 ± 0.2	0.38 (0.23 to 0.63)
18–49, n = 6543	2.3 ± 0.4	Reference
≥ 50, n = 7724	1.9 ± 0.2	0.80 (0.54 to 1.17)
Province or region
Atlantic provinces, n = 5308	2.9 ± 0.4	Reference
Quebec, n = 3204	1.5 ± 0.3	0.52 (0.31 to 0.87)
Ontario, n = 4228	1.5 ± 0.3	0.55 (0.32 to 0.94)
Prairies, n = 5146	2.4 ± 0.3	0.84 (0.54 to 1.29)
British Columbia, n = 2591	2.7 ± 0.7	0.99 (0.51 to 1.95)
Household education
Less than secondary school, n = 1780	1.6 ± 0.5	Reference
Postsecondary school, n = 3754	1.5 ± 0.3	0.83 (0.35 to 1.93)
Postsecondary degree or diploma, n = 14 903	2.0 ± 0.2	1.14 (0.50 to 2.62)
Ethnicity
White, n = 16 127	2.1 ± 0.2	Reference
Racialized or Indigenous, n = 3369	1.4 ± 0.5	0.68 (0.33 to 1.43)
Household income adequacy
Lowest to lower middle, n = 1318	1.6 ± 0.5	Reference
Middle to upper middle, n = 8496	1.5 ± 0.2	0.83 (0.35 to 1.96)
Highest, n = 10 663	2.2 ± 0.3	1.21 (0.52 to 2.86)

Table 2:

Total calories by type of food consumption location according to type of dietary avoidance(s)

Variable	Total kilocalories consumed, % (95% CI)
Variable	At home^*	Other locations^†	Not stated
Respondents who avoid dietary gluten, n = 488	81.0 (74.0 to 75.9)	15.4 (11.6 to 19.3)	3.6 (−0.2 to 7.4)
Respondents reporting ≥ 1 dietary avoidances,^‡ n = 2653	75.3 (75.7 to 86.2)^¶	23.0 (20.5 to 25.4)^¶	1.7 (1.0 to 2.4)
Respondents who report no dietary avoidances, n = 17 336	74.9 (74.0 to 75.9)^**	23.0 (22.0 to 23.9)^¶	2.1 (1.7 to 2.5)
Matched analysis^§
Respondents who avoid dietary gluten, n = 466	80.6 (75.2 to 85.9)	16.4 (12.3 to 20.6)	3.0 (−0.9 to 6.9)
Respondents reporting ≥ 1 dietary avoidances, n = 2304	74.9 (72.2 to 77.5)	23.4 (20.8 to 26.0)^¶	1.7 (1.0 to 2.4)

Note: CI = confidence interval.
↵* Home refers to foods prepared at the participant’s home or at someone else’s home.
↵† All other locations refer to the following locations: fast food or pizza restaurants; take-out; restaurants with server; bar, tavern or lounge; vending machine; restaurants with no additional information; cafeteria not at school; cafeteria at school; child care centre; family or adult care centre; other; grocery; corner or other types of stores; or at work.
↵‡ With the exception of gluten.
↵§ Respondents avoiding gluten were matched to respondents with ≥ 1 dietary avoidances according to age groups, sex, income adequacy and household education as described in the Methods.
↵¶ p < 0.01 in comparison with respondents who avoid dietary gluten.
↵** p < 0.05 in comparison with respondents who avoid dietary gluten.

Table 3:

Prevalence of exclusive at-home food consumption^* according to type of dietary avoidance(s)

Variable	Percent ± SE
Respondents who avoid dietary gluten	45.7 ± 0.5
Respondents who report ≥ 1 dietary avoidances other than gluten	36.8 ± 0.2^†
Respondents who report no dietary avoidances	37.8 ± 0.1^†

Note: SE = standard error.
↵* Home refers to foods prepared at the participant’s home or at someone else’s home.
↵† p < 0.01 in comparison with respondents who avoid dietary gluten.

Table 4:

Total calories for type of food preparation according to type of dietary avoidance(s)

Variable	Total kilocalories consumed, % (95% CI)
Variable	Home recipe or homemade	Restaurants^*	Other^†	No preparation required	Information not available
Respondents who avoid dietary gluten	12.2 (9.6 to 14.7)	2.0 (1.1 to 2.9)	10.5 (7.7 to 13.3)	54.9 (50.5 to 59.3)	20.4 (15.9 to 25.0)
Respondents reporting ≥ 1 dietary avoidances other than gluten	11.7 (10.6 to 12.9)	6.7 (5.4 to 7.9)^§	11.4 (10.5 to 12.3)	49.3 (47.8 to 50.9)^¶	20.9 (19.6 to 22.1)
Respondents who report no dietary avoidances	12.6 (12.1 to 13.2)	6.4 (6.0 to 6.9)^§	12.1 (11.6 to 12.6)	47.5 (46.8 to 48.2)^**	21.3 (20.7 to 21.9)
Matched analysis^‡
Respondents who avoid dietary gluten	12.2 (9.6 to 14.7)	2.6 (1.2 to 3.9)	9.7 (6.6 to 12.8)	53.5 (48.3 to 58.6)	22.9 (19.5 to 22.2)
Respondents reporting ≥ 1 dietary avoidances other than gluten	11.8 (10.7 to 13.0)	6.4 (5.1 to 7.7)^§	11.7 (10.7 to 12.6)	49.2 (47.6 to 50.7)	20.9 (19.5 to 22.2)

Note: CI = confidence interval.
↵* Includes fast food establishments.
↵† Includes dry mix, frozen or commercially packaged foods.
↵‡ Respondents avoiding gluten were matched to respondents avoiding ≥ 1 dietary avoidances according to age groups, sex, income adequacy and household education as described in the Methods.
↵§ p < 0.001 in comparison with respondents who avoid dietary gluten.
↵¶ p < 0.01 in comparison with respondents who avoid dietary gluten.
↵** p < 0.05 in comparison with respondents who avoid dietary gluten.