According to the WHO, food environment is one of the key factors to promote a healthy diet⁽¹⁾. Recent studies showed the influence of the food environment on food choices and food consumption which revealed the importance of monitoring food outlets and food quality in stores^{(Reference Ni Mhurchu, Vandevijvere and Waterlander2,Reference Minaker, Shuh and Olstad3)} . Moreover, processed foods represent a third of the total volume of food purchased in supermarkets and grocery stores in the province of Quebec (Canada)^{(Reference Plamondon, Durette and Paquette4)}. Processed foods are often high in fat, sugar and Na, and studies show that chronic overconsumption can lead to an increased risk of non-communicable diseases^{(Reference Srour, Fezeu and Kesse-Guyot5)}.

To better understand the food environment to which populations are exposed, many countries are monitoring food’s nutritional value and its evolution over time. The International Network for Food and Obesity/non-communicable diseases Research, Monitoring and Action Support (INFORMAS)^{(Reference Neal, Sacks and Swinburn6)} and the Food Monitoring Group^{(Reference Dunford, Webster and Metzler7)} already monitor food composition in different countries in order to support governmental regulation and voluntary commitments by industry in creating healthier food environments. In parallel, the Observatory of Food Quality in France (OQALI) evaluates the nutritional composition of different food categories. For instance, they observed an improvement in the nutritional composition of pizzas and ready-to-eat (RTE) meals (i.e. lower fat and saturated fat content) between 2009–2012 and 2015–2016⁽⁸⁾. The observed differences were mainly explained by product reformulation by the industry rather than changes in consumers’ choices towards healthier options. OQALI as well as other researchers in Europe and in the USA found that there is a high variability in nutritional quality among processed foods, even among products within a same food category^{(Reference Neal, Sacks and Swinburn6,Reference Dunford, Webster and Metzler7,Reference Baldridge, Huffman and Taylor9,10)} . Although an increase in use of sales data has been observed over the past 5 years^{(Reference Bandy, Adhikari and Jebb11)}, access remains very difficult for researchers and thus, a limited number of studies has combined such data with the nutritional composition found on food labels in order to estimate what consumers actually buy and eat. This combination is highly relevant since it could contribute to better target products for reformulation. Indeed, it may help to focus policy-makers efforts on the types of products that sell the most, since a small improvement in nutrient content of great sellers can have a large and significant impact on public health^{(Reference Korošec and Pravst12)}. Furthermore, it may allow to monitor and assess the impact of the introduction of new regulations (i.e. nutrition facts table, front-of-pack (FOP) labelling) on food purchases. Except for Na^{(Reference Arcand, Jefferson and Schermel13)} and sugar^{(Reference Bernstein, Christoforou and Weippert14)}, no study reporting overall nutritional value of food products in Canada has been yet published, which supports the relevance of monitoring the food environment and the nutritional quality of the food supply in provinces such as Quebec.

In 2016, the Quebec government created the very first government health prevention policy⁽¹⁵⁾, a policy of major importance aiming to improve population health and quality of life. Several actions have been established within a framework to improve the nutritional quality of the food supply and further encourage food companies to improve the nutritional quality of their products. Meanwhile, the implementation of an Observatory aiming to monitor the nutritional quality of the food supply was deemed a priority for a network of researchers and knowledge users (representatives from governmental, non-governmental, parapublic and private organisations). Hosted by the Institute of Nutrition and Functional Foods at Université Laval, the Food Quality Observatory (henceforth Observatory) was thus officially launched in 2016 and is currently supported by the Quebec’s Ministry of Health and Social Services as well as the Quebec’s Ministry of Agriculture, Fisheries and Food. By generating reliable and useful information on the nutritional quality of food products available, the Observatory aims to contribute to the creation of healthier food environments, which will in turn facilitate healthier food choices and likely improve the overall health of the population.

The food category of RTE breakfast cereals has been selected to test the methodology and the feasibility of the studies to be undertaken by the Observatory. Indeed, breakfast is an important meal of the day^{(Reference Barr, Vatanparast and Smith16–Reference Gibson and Gunn20)}, and RTE breakfast cereals are part of the daily diet of a large proportion of the population^{(Reference Leech, Boushey and McNaughton21 ,Reference Albertson, Anderson and Crockett22)} . Several studies which have analysed the impact of RTE breakfast cereals on dietary intakes and human health show variations in their nutritional value. Despite many positive impacts on diet quality (since they may provide whole grains, nuts, fruits, fibre, etc.) and cardiometabolic health^{(Reference Williams19,Reference Gibson and Gunn20,Reference Albertson, Thompson and Franko23–Reference Holmes, Kaffa and Campbell27)} , some RTE breakfast cereals are highly processed and high in some nutrients of public health concern (e.g. added sugar, Na and preservatives)^{(Reference Maschkowski, Hartmann and Hoffmann28,Reference Cordain, Eaton and Sebastian29)} .

It is also known that information on processed food products such as nutrition facts table, claims and other nutritional information can be difficult to understand for consumers^{(Reference Campos, Doxey and Hammond30)}. Strategies have been implemented to facilitate consumers’ food choices and to improve the nutritional quality of the food supply. Among these strategies, UK adopted in 2006 a voluntary FOP traffic light system coded for fat, saturated fat, sugar and Na^{(Reference Sacks, Rayner and Swinburn31)}. In 2013, the UK government published guidelines for uniform FOP colour-coded labelling⁽³²⁾. Since then, most of the UK supermarkets and many food manufacturers provide that label⁽³³⁾. Australia and New Zealand adopted in 2014 a voluntary Health Star Rating FOP system⁽³⁴⁾. Two years after the adoption of the FOP system, energy density and Na content were found to be lower whereas fibre content was higher in labelled products compared with their composition prior to the adoption of the FOP system^{(Reference Mhurchu, Eyles and Choi35)}. In 2016, Chile adopted a FOP warning symbol for food products exceeding specified amounts of energy, saturated fat, sugar and Na⁽³⁶⁾. After implementation, Chile observed that food companies reformulated products to adapt to the new regulation^{(Reference Quintiliano Scarpelli, Pinheiro Fernandes and Rodriguez Osiac37)}. All food categories combined, total sugar content showed the highest reduction after the FOP implementation, suggesting that sugar content of RTE breakfast cereals would thus be of major interest. The number of products with FOP ‘high in sugar’ before (with a simulation) and after implementation in Chile was significantly reduced in cereal products (e.g. cookies, crackers, cakes, breads) which included breakfast cereals. Indeed, median of total sugar almost had dropped by 50 % between 2013 and 2019, with 51 % of cereal products having a warning symbol in 2013 in comparison to 47 % in 2019. In 2017, a voluntary FOP label using letters from A to E was adopted to characterise the nutritional quality of food products in France (Nutri-Score)^{(Reference Ducrot, Méjean and Julia38)}. Since then, Belgium, Switzerland and Spain also adopted the Nutri-Score. In Canada, a standardised FOP warning symbol on food exceeding 15 % of the daily value (DV) for saturated fats, total sugar and Na is currently under consideration by the government^{(Reference Taillie, Hall and Popkin39)}. While it remains difficult at this point to confirm if nutrient-specific warning labels are more successful than summary labels^{(Reference Temple40)}, such a warning symbol could potentially act as a nudge for the food industry to reformulate their products while easily and rapidly informing consumers about less healthy food options. Moreover, this warning symbol would target specifically nutrients of interest which are known to be consumed in excess by consumers. In the case of RTE breakfast cereals, a FOP warning symbol – particularly for total sugar which is a nutrient of interest in this food category – could potentially affect a large number of products, including great sellers^{(Reference Goglia, Spiteri and Menard41)}.

Therefore, the aims of the present study were to generate a methodology to (1) test the use of sales data combined with nutrient values to characterise the nutritional composition of RTE breakfast cereals offered and purchased in the province of Quebec (Canada) and (2) verify the extent to which a FOP label based on the percentage of DV for total sugar, as a strategy to improve the food supply, would be distributed in this food category.

Results

A total of 331 different RTE breakfast cereals were identified in the Quebec food supply. Nutritional value and all packaging information were referenced for these cereals. Using the UPC, this dataset was merged with the sales database which contains more than 700 RTE breakfast cereals sold over 1 year. A total of 306 products with sales information were successfully cross-referenced with the 331 cereals identified in the food supply representing 92 % of RTE breakfast cereals identified in the Quebec food supply. The sales volume of products for which nutritional and purchasing information were both available amounted to CAD$ 230 million which represents 90 % of all sales of RTE breakfast cereals in Quebec. Products present in the sales database but missing in the nutritional database were mostly multiple packages with several varieties, discontinued products or different sizes of the products already included in the study.

Table 1 shows the variety of RTE breakfast cereals according to their type and purchase percentage. The most represented types of cereals were granola (36·6 %), sweetened (19·6 %), plain (15·4 %) and muesli cereals (10·3 %), whereas the most purchased were the sweetened (40·9 %) and the granola type (19·8 %).

Table 1 Availability and purchases of ready-to-eat (RTE) breakfast cereals according to their type

Table 2 shows the nutritional value and price per portion of all types of RTE breakfast cereals for both offered (as found on the shelves; n 331) and purchased RTE breakfast cereals (weighted by sales volume; n 306). A large variability was observed in saturated fat, total sugar and Na content of the different types of cereals. The variability was even higher in purchased than offered RTE breakfast cereals, emphasising once again on the importance of monitoring both food offered and purchased at the same time. Mean saturated fat content weighted for sales varied between 0·1 g (plain) and 2·7 g (granola) per 55 g of RTE breakfast cereals, while mean total sugar content varied between 6 g (plain) and 18 g (chocolate) and mean Na between 117 mg (granola) and 328 mg (plain). More particularly, when compared with others, granola cereals purchased had a higher energy, fat, saturated fat, protein content, a lower Na content and a similar total sugar content. Results remained similar when the unweighted nutritional composition of cereals was considered. Selling price of granola cereals was higher than other RTE breakfast cereals. When compared with others, sweetened cereals purchased had a higher total sugar content, and lower energy, fat and protein content. In addition to the previous results, when the unweighted nutritional composition was considered, Na content was higher and saturated fat and fibre contents were lower. Selling price of sweetened cereal was similar to others.

Table 2 Nutritional value and price (per 55 g serving) of ready-to-eat (RTE) breakfast cereals according to their type†,‡

* Significantly different from other cereals (P < 0·00078). This threshold equals to the Bonferroni correction for supply and purchases separately.

† Supply represents the average nutritional value of the cereals found on the shelves (n 331).

‡ Purchases represents the average nutritional value of cereals weighted by sales volume (n 306).

Figure 1 shows the large variation of total sugar content between the different types of cereal as well as between products within the same category. One RTE breakfast cereal out of five exceeded 15 % of the DV for total sugar (i.e. 15 g) and would get a FOP warning symbol according to Health Canada policy under review. More specifically, chocolate (65 %) and sweetened cereals (49 %) were those exceeding 15 % DV most often. Moreover, this figure illustrates the sales for each product and shows that many important sellers were sweetened cereals and most of them exceeded 15 % of the DV for total sugar. Actually, 65 % of sweetened cereals’ sales are above the 15 % of DV for total sugar.

Fig. 1 Distribution of sugar content of different types of ready-to-eat (RTE) breakfast cereals and their sales volume. The bigger the circles, the higher the sales (kg). Signs + represent RTE breakfast cereals for which sales data were not available