Health Reports
Trends and correlates of frequency of fruit and vegetable consumption, 2007 to 2014

by Cynthia K. Colapinto, John Graham and Sylvie St-Pierre

Release date: January 17, 2018

Fruit and vegetable consumption is recommended as part of a healthy diet.Note 1 Fruit and vegetables are a source of vitamins and minerals, including folate, vitamin A, vitamin C, and carotenoids.Note 2 They also provide fibre, which is important for digestive health. Diets that include fruit and vegetables have been linked to a lower risk of some chronic conditions, including cardiovascular disease, type 2 diabetes, and colorectal cancer.Note 3Note 4Note 5 High consumption of fruit and vegetables suggests better diet quality.Note 6

For people aged 12 or older, the 2007 Food Guide recommended 6 to 10 servings of fruit and vegetables a day.Note 7 However, results of the 2004 Canadian Community Health Survey (CCHS), which used a 24-hour recall to collect nutrition data, showed that more than 50% of Canadians aged 12 or older consumed fewer than the recommended number of servings for their age and sex group.Note 8 According to the 2014 CCHS–Annual component, the frequency of fruit and vegetable consumption, which is a validated indicator of diet quality,Note 6 was low, with fewer than 45% reporting at least 5 times a day.Note 9

Unlike discrete time-points, linear trends in the frequency of fruit and vegetable intake allow for an understanding of change over time. Based on annual data from the CCHS, the present analysis describes trends in the frequency of fruit and vegetable intake among Canadians aged 12 or older from 2007 to 2014. The contribution of 100% pure fruit juice to these trends, and how fruit and vegetable intake differed by socio-demographic characteristics and body mass index (BMI) are also explored.

Data and methods

The CCHS—Annual componentNote 10 is a cross-sectional survey that collects information about health status, health care utilization, and health determinants. The survey covers the population aged 12 or older in the 10 provinces and 3 territories. It excludes: residents of reserves and other Aboriginal settlements in the provinces; full-time members of the Canadian Forces; the institutionalized population; children aged 12 to 17 in foster care; and residents of the Quebec health regions of Région du Nunavik and Région des Terres-Cries-de-la-Baie-James. Together, these exclusions represent less than 3% of the Canadian population aged 12 or older. In the north, the CCHS covers 92% of the targeted population in the Yukon and 96% in the Northwest Territories. In Nunavut, starting in 2013, coverage was extended to represent 92% of the targeted population; previously, coverage was 71%, as the survey included only the 10 largest communities.

Estimates for this study are based on consecutive years of CCHS data from 2007 to 2014. About 65,000 respondents were interviewed each year. The analyses pertain to respondents who answered questions about frequency of fruit and vegetable intake (approximately 60,000 per year).

Frequency of fruit and vegetable consumption

“Fruit and Vegetable Consumption” was a core module on the CCHS questionnaire from 2007 to 2014. The module consisted of six questions adapted from the fruit and vegetable module of the Behavioral Risk Factor Surveillance System of the Centers for Disease Control in the U.S.,Note 11 which captures self-reported frequency of intake as the number of times per day, week, month or year, rather than the amount (number of servings) consumed. The derived variable (DV) for total frequency of fruit and vegetable intake per day was used, which combined questions on the following foods and drinks, whether consumed at meals or snacks, at home or away: 1) 100% pure fruit juice such as orange, grapefruit or tomato; 2) fruit, not including juice; 3) green salad; 4) potatoes, not including french fries, fried potatoes, or potato chips; 5) carrots; and 6) “other vegetables.” The “other vegetables” response was considered in the DV as the number of times per day, week, month or year, although the question was phrased as the number of “servings.”

Frequency of fruit juice consumption

Because nutrition recommendations advocate eating fruit and vegetables rather than drinking juice, the DV for the frequency of fruit and vegetable intake, excluding juice, was used. The question on how many times per day respondents drank 100% pure fruit juice was used to examine the frequency of juice intake separately.

Covariates

Age was classified into three groups: children and adolescents (12 to 18), adults (19 to 50), and older adults (51 or older).

Sex was a self-reported dichotomous variable indicating male or female.

Household income deciles were produced for the 10 provinces. They account for rural/urban location and household size consistent with pre-tax low-income cut-offs relative to a 1992 base year.Note 12 The deciles were collapsed into quintiles. Because income information was not available for the territories, income estimates were not produced for these jurisdictions.

Region was categorized as: Atlantic (Newfoundland and Labrador, Prince Edward Island, Nova Scotia, and New Brunswick), Quebec, Ontario, Prairies (Manitoba, Saskatchewan, and Alberta), British Columbia, and territories (Yukon, Northwest Territories, and Nunavut).

Body mass index (BMI) was based on self-reported height and weight and calculated by dividing weight in kilograms by height in metres squared (kg/m2). In accordance with Health Canada guidelines, adults were classified as: neither overweight nor obese (BMI less than 25), overweight (BMI 25 to less than 30) or obese (BMI 30 or more).Note 13 For respondents aged 12 to 17, age- and sex-specific cut-points defined by the World Health Organization were used to classify BMI.Note 14 Analyses that used BMI excluded female respondents aged 15 or older who were pregnant or who did not answer the CCHS pregnancy question.

Statistical analyses

Linear regression assessed average annual changes during the 2007-to-2014 period in: 1) total frequency of fruit and vegetable intake; 2) frequency of fruit and vegetable intake excluding fruit juice; and 3) frequency of fruit juice intake. Rates were adjusted to the age structure of the Canadian population aged 12 or older as of July 1, 2014 to yield more valid comparisons of aggregate frequency of fruit and vegetable consumption rates over time and between populations.

With weighted frequencies and cross-tabulations, the average number of times per day fruit and vegetables were consumed was estimated by socio-demographic characteristics and BMI. Correlates of the frequency of consumption were examined with multivariate logistic regression, using a dichotomous outcome variable of less than 5 times per day versus 5 or more times per day, which is considered a proxy for better diet quality.Note 6 Multi-collinearity was assessed using PROC REG and a variance inflation factor of 4 as a cut-off point for variable selection to ensure that the variables were not strongly correlated with others in the logistic regression models. Because income information was not available for the territories, region was excluded from the multiple logistic regression analyses.

Analyses were performed with SAS 9.3. Point estimates were generated with PROC SURVEYLOGISTIC, and bootstrap replicate weights were applied using BOOTVAR V3.1 for variance estimation (95% confidence intervals) and significance testing to account for the survey’s complex sampling design.Note 15Note 16Note 17

Results

Slight decrease in frequency between 2007 and 2014

Canadians’ average frequency of fruit and vegetable consumption (including juice) was 4.7 times a day in 2014, down from 5.0 times in 2007—a small, but significant, decrease (annual average decline of 0.05 times a day) (Table 1, Figure 1).

This trend was apparent across age groups, with annual decreases in consumption frequency of 0.07 times a day at ages 12 to 18; 0.04 times a day at ages 19 to 50; and 0.05 times a day at age 51 or older. Among both males and females, the annual decrease was 0.05 times a day.

By household income, the largest annual drop in the frequency of consumption (0.06 times a day) was among the lowest quintile, and the smallest (0.03 times a day) was among the highest. Annual decreases were observed across regions (except for the territories)—0.07 times a day in Quebec; 0.05 times a day in the Atlantic provinces and Ontario; and 0.04 times a day in British Columbia and the Prairies. Annual decreases were 0.04 times a day among people in the neither overweight nor obese BMI category, and 0.05 times a day in the overweight and obese categories.

No significant decline when fruit juice excluded

To a considerable extent, these decreases reflected a slight decline in the frequency of fruit juice consumption from an average of 0.9 times a day in 2007 to 0.6 times a day in 2014, a slight but significant annual decline of 0.04 times a day (Figure 1).

When fruit juice was excluded from fruit and vegetable intake, the average frequency of consumption did not change between 2007 and 2014 (4.1 times a day in both years) (Figure 1, Table 1). As well, the trend no longer indicated significant decreases by age (except age 51 or older—an annual decline of 0.02 times a day), sex, BMI (except those who were obese—0.01 times a day), household income, or region (except Quebec—0.02 times a day). Slight increases were recorded for the highest income quintile (0.02 times a day) and the territories (0.05 times a day).

Excluding fruit juice, males’ average frequency of fruit and vegetable consumption was lower than females’ in both 2007 and 2014 (3.6 versus 4.5 times a day). As well, gradients observed in 2007 persisted in 2014, with frequency of consumption being lower with decreasing household income and rising BMI. In both 2007 and 2014, the frequency of consumption was lowest in the Atlantic provinces and the territories, and highest in Quebec.

Correlates of intake frequency in 2014

Results of logistic regression analyses show that, even when age, household income and BMI were taken into account, in 2014, females were significantly more likely than males to report consuming fruit and vegetables 5 or more times a day (OR 1.7, 95% CI: 1.6 to 1.8) (Table 2). The odds of reporting at least 5 times a day were significantly lower for adults aged 19 to 50 (OR 0.5, 95% CI: 0.5 to 0.6) or 51 or older (OR 0.5; 95% CI: 0.5 to 0.6) than for 12- to 18-year-olds.

Compared with people in the lowest household income quintile, those in the highest had significantly greater odds of reporting at least 5 times a day (OR 1.2; 95% CI: 1.1 to 1.4), and those in the low-middle quintile had significantly lower odds (OR 0.9, 95% CI: 0.8 to 1.0).

People who were overweight (OR 0.9, 95% CI: 0.8 to 1.0) or obese (OR 0.7, 95% CI: 0.6 to 0.8) were less likely than those who were neither overweight nor obese to report at least 5 times a day.

When fruit juice was excluded, many of the same relationships were observed. For instance, females’ odds of reporting 5 or more times a day continued to exceed those of males (OR 1.8, 95% CI: 1.7 to 1.9).

Similarly, older age groups still had significantly lower odds (ages 19 to 50 OR 0.4, 95% CI: 0.4 to 0.5; age 51 or older OR 0.4, 95% CI: 0.4 to 0.5) of reporting at least 5 times a day, compared with children and adolescents.

People in middle income groups were significantly less likely than those in the lowest to report 5 or more times a day (high-middle OR 0.8, 95% CI: 0.8 to 0.9; middle OR 0.8, 95% CI: 0.7 to 0.9; low-middle OR 0.7, 95% CI: 0.6 to 0.8).

Individuals who were overweight (OR 0.9, 95% CI: 0.8 to 0.9) or obese (OR 0.7, 95% CI: 0.6 to 0.8) had lower odds of reporting at least 5 times a day than did those who were neither overweight nor obese.

Discussion

In Canada, as in other countries,Note 18Note 19 fruit and vegetable intake is lower than recommended.Note 8Note 20Note 21 Nationally representative data from 2007 to 2014 indicate that Canadians’ reported frequency of fruit and vegetable consumption was consistently low and decreased slightly (by an average of 0.05 times a day per year, or a total of 0.3 times a day over the period). This was largely attributable to slightly less frequent fruit juice consumption; when fruit juice was excluded from the calculations, the decrease was not significant.

The slight drop in how often Canadians drank fruit juice may reflect a change in eating habits, possibly due to concern that juice is a source of free sugars.Note 22 However, additional research is required to understand factors influencing the amount of juice consumed.

Sex, age, household income, and BMI were correlates of the frequency of fruit and vegetable intake, whether fruit juice was included or not. People who reported consuming fruit and vegetables at least 5 times a day in 2014 tended to be female, children or adolescents, in the highest income quintile, and neither overweight nor obese.

The low frequency of fruit and vegetable intake at lower income levels may be associated with limited availability (the supply of food to a region or community) and limited access (the ability of an individual or household to acquire nutritious food).Note 23 Socio-demographic factors have been related to reduced nutrient intake.Note 24Note 25 For example, a study based on data from the first 24-hour recall from the 2004 Canadian Community Health Survey—Nutrition found that adolescents and adults in food-insecure households had poorer diets, including lower intake of fruit and vegetables.Note 25 Regional variations in consumption may reflect less availability in some areas.Note 23

Consistent with other research,Note 26Note 27Note 28 lower frequency of consumption was associated with higher BMI. A U.S. study with more than 400,000 participants, which was based on data from the 2007 Behavior Risk Factors Surveillance System, reported an inverse association between fruit and vegetable intake and obesity.Note 26 However, evidence of an association between fruit and vegetable consumption and prevention of weight gain or reduction of obesity risk is limited.Note 29Note 30Note 31

Strengths and limitations

A major strength of this study is the large, nationally representative dataset with uniform questions that allow trend analysis. It is limited by reliance on the “frequency” of intake outcome variable—type of fruit or vegetables could not be examined, and portions could not be quantified. Because the data were self-reported, estimates of consumption frequency and of BMI may be subject to error. As well, although survey questions specifically indicated that intake of 100% fruit juice does not include fruit-flavoured drinks or fruit punch, respondents may not have distinguished “fruit juice” from “fruit drink,” which could over- or underestimate the frequency of juice intake. Because household income was not available for the territories, region was excluded from the multivariate regression models. Finally, the fruit and vegetable module of the CCHS changed in 2015; as a result, statistical comparisons cannot be directly made with earlier years.

Conclusion

The frequency of fruit and vegetable intake in Canada is consistently low. Correlates of fruit and vegetable consumption indicate target populations that could be considered when planning nutrition policy and education initiatives.

References
Date modified: