1. Background
In recent years, Canada has seen significant changes in dietary patterns, with more Canadians consuming diets that are excessive in energy intake but inadequate in nutrients and key food groups including fruit, vegetables, whole grains, dairy, and fiber [
1,
2]. Poor dietary habits may contribute to an increased risk of overweight or obesity and other chronic diseases among children and adults [
3]. Overweight/obesity is of increasing public health concern in Canada with the rates of 23% and 54% in adolescents and adults, respectively [
4]. These differences in rates may be attributed to some factors, including socioeconomic status and lifestyle behaviors, such as dietary intakes, eating habits, and physical activity.
Ready-to-eat cereal (RTEC) is a popular breakfast option in many countries, including Canada, and the majority of RTEC consumption occurs at breakfast. RTECs are defined as any processed cereal that can be eaten without further preparation [
5]. However, RTEC products can be high in added sugar due to commercial purposes, and a RTEC breakfast supplies more glucose and fructose in comparison to a bread breakfast, but overall it would not lead to a higher consumption of simple sugars over a full day [
5]. RTECs are typically grain-based (often whole grain), with formulations consisting mainly of rice, corn, wheat, and oats. There are over 160 varieties of ready-to-eat cereals available across Canada, many of which are fortified with vitamins and minerals, including folic acid, thiamin, niacin, pantothenic acid, vitamin B
6, zinc, and iron [
1,
6]. Generally, RTECs are associated with better overall diet such as lower fat and a higher fiber intake, and improved body mass index outcomes [
7].
Shifts are occurring in nutrition research and dietary recommendations to focus more on food-based, rather than nutrient-based, recommendations. Therefore, further research is needed to understand the associations between specific foods and dietary and health outcomes. Measures of overall diet quality can also be particularly useful. The Nutrient-Rich Food Index 9.3 (NRF 9.3) applies to individual foods, but can also be used to measure the nutrient density of the overall diet, thus making it a useful tool in assessing the nutrient density of individuals’ diets based on their intakes [
8].
In order to determine the role of RTEC in the Canadian diet, the recent nationally representative dietary survey, the Canadian Community Health Survey (CCHS) 2015, had been used to evaluate how RTEC consumption contributed to daily energy and nutrient intakes, and then compare them with non-consumers, as well evaluating the contribution of milk co-consumed with RTEC to total daily milk consumption. The other objective is to represent the association of RTEC with diet quality (measured using the NRF 9.3 applied to the total diet) nationally and provincially, and health status of Canadians by age, sex, region of residence, and socioeconomic status.
4. Discussion
To our knowledge, this is the first study showing that Canadian RTEC consumers had more nutrient-dense diets. RTEC is a popular food in Canada, with approximately 22% of Canadians consuming RTEC, particularly among children, who are the highest consumers of RTEC compared to adolescents and adults. It had been found that RTEC consumers, compared to non-consumers, had higher daily intakes of key micronutrients including vitamin B
12, B
6, folate, vitamin A, vitamin C, vitamin D, calcium, magnesium, zinc, and phosphorous, which are considered as shortfall nutrients [
19]. This may be due in part to the healthier overall diets of RTEC consumers, but RTEC itself—either alone or combined with milk—contributed key nutrients to the diets. Additionally, frequent RTEC consumption was associated with better nutrient intake profiles and higher whole grain intake from RTEC among RTEC consumers in different age groups. Lastly, we found that there was no significant differences between BMI among RTEC consumers and non-consumers.
The rate of RTEC consumption varies across the globe. Our findings indicated that over one-fourth of Canadians were RTEC consumers, and the prevalence of RTEC consumption was higher among 2 to 12-year-old children (37.6%) compared to the other age groups. Over 26 years ago, Sommerville and O’Reagan reported that 86.4% of Ireland’s population between 8–18 years were RTEC consumers [
20]. In 1993, Crawley found that in the United Kingdom, 78.7% of males and 63.1% of females aged 16–17 years old consumed RTEC [
20]. In Greece, 26.9% of the adolescents consumed RTECs regularly, and 43% of them consumed at least once a week [
21]. However, a relatively recent study reports around 65% of European adolescents who participated in a study in nine countries consumed RTEC at least once a week [
5]. Despite some variability across region and time, RTEC has been and continues to be a popular dietary choice, particularly among children.
Studies have suggested that the consumption of RTEC contributes to a balanced diet with a lesser proportion of energy provided by fats and a higher proportion of fiber and carbohydrate intake [
22]. However, one cannot ignore the added sugar content that might make RTEC more pleasant and tasty to eat [
22]. In our study, the daily fat intake was lower, while the intakes of vitamin B
12, vitamin B
6, folate, riboflavin, thiamin, sodium, potassium, zinc, magnesium, iron, and calcium were higher among RTEC consumers compared to non-consumers. RTEC consumers’ total sugar intake was higher than non-consumers in the total population, and for the other age groups as well. Total sugar intake did not differ between children who ate RTEC and those who did not. However, the CCHS dataset does not contain information on added sugar intake, so it is possible that dietary sources other than RTEC are contributing to this total sugar intake, including higher fruit intake and higher milk intake [
2]. When we looked specifically at the contribution that RTEC consumed with milk made to the diet, it had been found that RTEC contributed 20% to 40% of the daily intake of fiber, vitamin B
6, vitamin A, vitamin B
12, calcium, thiamin, folic acid, iron, and vitamin D. RTEC and milk combined contributed to 19% of the total sugar intake but alone (without milk), RTEC contributed to 9.5% of the total sugar intake, which is proportional to its contribution to energy intake (8.9%).
A large proportion, 66%, of milk consumed in a day was consumed with RTEC, particularly for adolescents (71% of milk). Milk consumption with RTEC was highest among adults ≥19 years across all the regions, but was highest in British Columbia, where approximately 3/4 of all milk consumption is with RTEC.
In Canada, it is permitted to fortify cereal breakfast with the type and amount of micronutrients that are specified by Health Canada, including thiamine, niacin, vitamin B
6, folic acid, pantothenic acid, magnesium, iron, and zinc [
1]. Hence, it is not surprising, to find these significant differences. The higher vitamin D intake in RTEC consumers is probably because of co-consumption with milk through mandatory vitamin D fortification in Canada, and overall healthier dietary choices. It is not common to fortify RTEC items with vitamin D. Similar results have been previously reported in the United States (USA) [
23], where studies found that RTEC consumer adults and children had a lower daily intake of total fat, saturated fatty acids, and cholesterol [
24]. In the Bogalusa Heart Study [
25], adults consuming RTEC also had higher intakes of total carbohydrates, both starch and total sugars, than those who did not eat cereals (who consumed a higher intake of fat) as we found in our study. In another population-based survey of Canadians aged 12 years and older in 2004, the mean intakes of thiamin, riboflavin, niacin, folic acid, vitamin A, vitamin B
6, vitamin B
12, and iron were higher among RTEC consumers [
1]. The same phenomenon has been observed in Albertson’s 2013 study [
1] in Canada, which demonstrated that those who consumed RTE cereal (participants age 55 and older in 2008) most often had improved micronutrient intakes and were more likely to meet the dietary reference intake standards, compared with those consumed RTEC less often or not at all. These results are in agreement with the past research conducted in the USA [
6,
25,
26,
27,
28,
29,
30,
31], reflecting the significant contribution of RTEC to nutrient intake and diet quality. The improved nutrient intake profile seems to be largely related to the consumption of RTEC, the foods that RTEC could be replacing, and a pattern for healthful eating throughout the day.
On the other hand, our findings in terms of lower sodium intake in RTEC consumers was different from the findings by Susan Barr in 2013 [
30], who reported no significant difference in sodium intake between RTEC consumers and non-consumers. This is likely due to the decreasing trend toward sodium levels in RTEC (in the case of Canada). This decline might be owing to Health Canada’s recent efforts that showed that voluntary sodium reduction in processed foods accounted for a decrease of 8% in average daily sodium intake between 2010–2016. According to the report on Sodium Reduction in Processed Foods report [
32], the sodium reduction in Canada for RTEC has been conducted in three phases from 2012 to 2017. Initially, the baseline level was 558 mg sodium per 100 g of RTEC, and it reduced to 490 mg/100 g, 430 mg/100 g, and 360 mg/100 g in phases I, II, and III, respectively. Although the measured level should be 395 mg/100 g of RTEC in 2017, it is reported that Phase-II targets were met, which means that RTEC have partially met the sodium reduction goal [
32].
The total grain consumption from RTEC among RTEC consumers was higher among ≥19-year-old adults who consumed nearly 33% of grain via RTEC, of which approximately 64% was allocated to the whole grain among RTEC consumers. To our knowledge, there is no study reporting the proportion of whole grain consumption from RTEC among consumers in Canada. The previous version of Canada’s Food Guide recommends three to eight servings/day (age and sex-dependent) of grain products, and advises making at least one-half of the grain product choices whole grain each day [
19]. The minimum content of whole-grain consumption is recommended to be 8 g of whole grain per 30 g of cereal (in other words, 27 g of whole grain per 100 g) [
33]. Canada’s Food Guide recommends 30 g in cold cereal and 150 g in hot cereal [
34]. Canada’s new dietary guidelines are encouraging whole grain intake as the primary source of the grain products [
34]. Considering the proportion of Canadians consuming RTEC, particularly children and adolescents, RTEC can be considered one of the means for promoting whole grain consumption.
The NRF 9.3 index is preferred for evaluating the nutrient density and diet quality, because it includes the need to encourage nutrients of public health importance such as proteins, fibers, vitamin A, vitamin C, vitamin D, calcium, iron, magnesium, and potassium, and to limit fat, added sugars, and sodium [
35]. The NRF 9.3 index can be applied to individual foods, meals, and total diets, and diets assigned higher NRF scores were associated with a higher consumption of foods and nutrients to encourage and lower energy-dense foods [
35]. The observed results for NRF scores between RTEC consumers and RTEC non-consumers indicated that RTEC consumption increased the nutrient-rich food score across all age groups. Similar to data from the USA [
31], adults aged ≥19 years old had the highest score intake of RTEC among all the age groups. At the provincial level, adults in British Columbia had the highest score. The higher contribution of milk consumption along with RTEC to this province may explain the highest score. No similar study was available in other countries to compare with the results of our study.
In addition to contributions to research and informing the public, this study may provide the food industry with a general picture of RTEC nutrients and daily energy intake contribution in order to alter their products to be more healthy and beneficial. This study also would benefit the monitoring bodies to track the RTEC consumption nationally and regionally based on their policies.
Our study used CCHS 2015 Nutrition data, which is a comprehensive nutrition survey and represents all Canadians. Over-reporting was identified during analysis, and nutrients with an unrealistic higher intake were excluded. The other strengths of our study include using measured BMI (not self-reported) for anthropometry measurements, adjusting for key confoundings, and reporting the results at the national and regional level. The limitations are that the cross-sectional design of the study does not allow any causality inference. Our study included information based on one day of self-reported 24-h recall, which is subject to over and under-reporting, and could possibly not represent usual food or nutrient intake along with weekend food consumption. Although the mean of one-day intake in national survey data may be similar to data from two days of 24-h recall (collected in national surveys), using data from serial 24-h recall would provide more robust estimates of usual intake. A modified NRF 9.3 index had been used with some modifications as described in our methods, because data on vitamin E and added sugar were not available in the dataset. For recognizing the diet quality, in this study, total sugar was considered instead of added sugar, which prevented us from identifying the exact amount of sugar consumption that was added to food during their production. Hence, providing data on added sugar in national surveys would be beneficial.