The Mediterranean diet (MedDiet) is a traditional dietary pattern based on a high consumption of plant-based foods (vegetables, fruits, nuts, legumes and minimally processed cereals); low consumption of meat and meat products; moderate-to-high consumption of fish and low consumption of dairy products (with the exception of yogurt and the long-preservable cheeses). The total fat intake may be high, but the ratio of the beneficial monounsaturated to the non-beneficial saturated lipids is high as well. This is due to the high monounsaturated content of liberally consumed olive oil, which represents a hallmark of the MedDiet as the main culinary fat(Reference Trichopoulou, Martínez-González and Tong1).
The cultural heritage aspect of the (MedDiet) was officially recognised by UNESCO in 2010(Reference Willett, Sacks and Trichopoulou2,Reference Bach-Faig, Berry and Lairon3) . However, in many Mediterranean countries the MedDiet is gradually being replaced by western dietary patterns, which are primarily based on animal products and ultra-processed foods (UPF), resulting in high intakes of refined carbohydrates, added sugar, saturated fats and Na(Reference Pereira-Da-Silva, Rêgo and Pietrobelli4). Spain is one of those Mediterranean countries. Over the last two decades, the dietary pattern of Spanish children has shifted drastically, with an alarming substitution of fresh foods with UPF like snacks, sugar-sweetened beverages and ready-to-eat meals(Reference Latasa, Louzada and Steele5).
The transition from a traditional to a Western dietary pattern has been promoted by the sociocultural changes that accompanied industrialisation, which, together with the globalisation of food production, resulted in shared food behaviours worldwide(Reference Popkin, Adair and Ng6). Far from meeting the world’s dietary needs, global food systems are determining the world’s dietary pattern, with three-quarters of total sales coming from UPF in the food market worldwide(Reference Stuckler and Nestle7).
UPF are formulations of ingredients, which are created from extracted isolated substances derived or not from food constituents and added additives whose function is to make the food product palatable or often hyper-palatable(Reference Monteiro, Cannon and Levy8,Reference Monteiro, Cannon and Levy9) . These substances are primarily used for exclusive industrial purposes and their production involves several industrial processes among different industries(Reference Monteiro, Cannon and Levy9). UPF also contain a wide variety of flavouring and colouring agents in order to imitate, intensify or improve the sensory qualities of the final product. Therefore, UPF are generally rich in free sugar, oils, fats, salt, synthetic antioxidants, stabilisers and chemical additives(Reference Monteiro, Cannon and Levy8,Reference Monteiro, Cannon and Levy9) . Previous studies have reported that higher consumption of UPF was associated with lower intakes of polyunsaturated fats, vitamins A, B12, C and E, Ca, Zn and fibre, and higher intakes of Na, free sugar and trans fats(Reference Cornwell, Villamor and Mora-Plazas10–Reference Martínez Steele, Popkin and Swinburn16).
Recent studies among Spanish populations found that 31·7 % of the daily energy household availability came from UPF(Reference Latasa, Louzada and Steele5) and a higher consumption of UPF was associated with a greater risk of overweight and obesity(Reference Mendonça, Pimenta and Gea17), hypertension(Reference Mendonça, Lopes and Pimenta18) and all-cause mortality(Reference Rico-Campà, Martínez-González and Alvarez-Alvarez19,Reference Blanco-Rojo, Sandoval-Insausti and López-Garcia20) . Within this context, we hypothesised that higher adherence to the MedDiet may lead to lower consumption of UPF. Therefore, the main objective of this study was to assess whether higher adherence to the traditional MedDiet was associated with lower consumption of UPF in Spanish pre-schoolers. As a secondary objective, we aimed at quantifying the reduction in free sugar intake associated with higher adherence to the traditional MedDiet.
Methods
Selection of participants
The SENDO project (Seguimiento del Niño para un Desarrollo Óptimo) is a prospective and dynamic paediatric cohort of Spanish children focused on assessing the impact of children’s diet and lifestyle on their health during childhood and adolescence. This project started in 2015 as an initiative of the Department of Preventive Medicine and Public Health of the University of Navarra and the Public Health Service of Navarra. The recruitment in this cohort is permanently open. The inclusion criteria are: (1) age: 4 to less than 6 years old and (2) residence: Spain. The only exclusion criterion is inaccessibility to internet. All of the participants’ parents signed an informed consent at recruitment. Sociodemographic, dietary and lifestyle information is gathered at baseline and updated every year through online questionnaires. Further information on this cohort study design has previously been reported in detail elsewhere(Reference Romanos-Nanclares, Zazpe and Santiago21).
Of the 485 children eligible for the analyses, 91 (18·7 %) were excluded due to missing data on dietary information and 8 (2·0 %) more due to reported energy intakes out of the predefined limits (below percentile 1 or above percentile 99). Thus, the final sample consisted of 386 participants with complete information.
Data collection
The participants’ parents completed a self-administered online questionnaire on sociodemographic, lifestyle and dietary habits at baseline. For this study, we used information on participant’s sex (male or female), age (quantitative), breast-feeding history (yes or no) and physical activity (quintiles of Metabolic Equivalent of Task (MET)-h/week). Physical activity was collected with a questionnaire that included fourteen activities and ten response categories, from never to eleven or more hours per week. MET-h/week for each activity were calculated by multiplying the number of MET of each activity(Reference Ainsworth, Haskell and Leon22) by the weekly frequency of participation in that activity, weighted according to the number of months dedicated to it. Total physical activity was quantified by summing the MET-h/week dedicated to all activities performed during leisure time. Regarding parental data, we used information on maternal age (quantitative), family history of obesity (yes or no) and parent’s maximum education level (high school or lower, university graduate or university master/doctorate).
Dietary information was collected through a semi-quantitative FFQ which included 149 food items. For each food item, a portion size was specified. Parents reported how often their child had consumed each of the food items over the previous year by choosing one out of nine frequencies of consumption ranging from ‘never or almost never’ to ‘6 or more times per day’. Nutrient content of each food item was calculated by a team of specialised dietitians by multiplying the frequency of consumption, by the edible portion and the nutrient composition of the specified portion size, using data from updated Spanish food composition tables(Reference Tuni, Carbajal and Forneiro23) and online databases. We considered free sugar as those added to foods and beverages by the industrial processing industrial or homemade preparation and those naturally present in honey, syrups and fruit juices(24).
All food items were classified by their type of processing according to the NOVA classification (Box 1). Food processing, as identified by NOVA, involves physical, biological and chemical processes that occur after foods are separated from nature, and before they are acquired and submitted to culinary preparation or directly consumed as such(Reference Monteiro, Cannon and Moubarac25). The first group includes unprocessed or minimally processed foods (MPF): no processing or mostly physical processes used to make single whole foods more durable, accessible, convenient, palatable or safe. The second group contains processed culinary ingredients: refined substances obtained by extraction and purification of foods or other natural resources that are used, in combination with foods in group 1, in the preparation of meals in households or traditional restaurants. The third group comprises processed foods: relatively simple products made by adding sugar, oil, salt or other ingredients in group 2 to foods in group 1. Processing includes several preservations, cooking or fermentation methods. And the fourth group comprises UPF and drink products: typically industrial formulations made by adding sugar, oils, fats, salt, synthetic antioxidants and stabilisers to foods in group 1, which represent only a small proportion of the final product(Reference Monteiro, Cannon and Levy9,Reference Monteiro, Cannon and Moubarac25) . UPF are made from isolated substances, derived or not from foods constituents, which are primarily for exclusive industrial use and several chemical additives, resulting in a product with no (or almost no) identifiable intact food within it. Examples include sugar-sweetened beverages, fast food products (sausages, burgers), cookies, candy sweet or savoury packaged snacks, and sugared milk and fruit drinks(Reference Monteiro, Cannon and Levy9).
Box 1 Classification of foods in the SENDO food frequency questionnaire according to the degree of processing by NOVA
* There are foods that could have different ratings depending on the way they are prepared: homemade or industrialised. In these cases, we chose to classify them as ultra-processed foods because most traditional foods have been replaced by industrial food products in supermarkets
Total energy intake (TEI) was obtained summing the energy content of each food item. To calculate the percentage of energy from each group of the NOVA classification, we divided the energy content of each group by TEI.
Adherence to the MedDiet was calculated with the KIDMED index (Box 2), a previously validated index(Reference Serra-Majem, Ribas and Ngo26) that assesses the adherence to the MedDiet by children and adolescents. The KIDMED consists of sixteen questions: negative connotations regarding MedDiet (items 6, 12, 14 and 16) were assigned a score of –1 and those with positive connotations (the rest of the items) scored +1. The score of the KIDMED index ranges from –4 to +12 points. According to their score, participants were classified as having low (≤3 points), medium (4–7 points) or high (≥8 points) adherence to the Mediterranean dietary pattern(Reference Serra-Majem, Ribas and Ngo26). The KIDMED index in general and that classification, in particular, were consistently reported to be good predictors of diet quality(Reference Mariscal-Arcas, Rivas and Velasco27,Reference Peng, Berry and Goldsmith28) , body composition(Reference Galan-Lopez, Sánchez-Oliver and Ries29,Reference Archero, Ricotti and Solito30) and health-related outcomes(Reference Martino, Puddu and Lamacchia31,Reference Salcin, Karin and Damjanovic32) in children and adolescent.
Box 2 KIDMED index to assess adherence to Mediterranean diet in children and adolescents scoring
Information about physical activity was reported by the participants’ parents at baseline. It was gathered using a validated questionnaire which consisted of fourteen activities, including sports and games, and nine response categories from ‘never’ to ‘more than 11 hours per week’(Reference Ainsworth, Haskell and Leon22).
Statistical analysis
We described participants’ main characteristics by sex. The results are presented as frequency (percentages) for categorical variables, and means and sd for continuous variables. χ 2 tests or Student’s t tests were used to assess the statistical significance of the differences of proportions and means, respectively.
Linear trend tests by adherence to MedDiet were calculated to analyse the contribution of each food item and each group (according to NOVA classification) to TEI.
Generalised estimating equations with Gaussian distribution were used to evaluate the association between adherence to the MedDiet (as a continuous variable and categorised in three levels) and the energy intake from UPF (continuous), while accounting for intra-cluster correlation between siblings. We calculated crude and multivariable adjusted differences (95 % CI) in the percentage of energy intake from UPF associated with (1) two additional points in the KIDMED score and (2) medium and high adherence compared with low adherence to the MedDiet. The multivariable adjusted model was controlled for sex (male or female), participant’s age (continuous), total dietary energy intake (quintiles), physical activity (quintiles of MET-h/week), breastfeeding (yes or no), maternal age (continuous), family history of obesity (yes or no) and parents’ maximum education level (high school or lower, university graduate or university/doctorate). To assess the robustness of our findings, we repeated the analyses moving the food item ‘yogurts’ from the MPF group to the UPF group, considering most yogurt consumed by children is sweetened and artificially flavoured, which changes its classification according to NOVA.
Additional analyses were performed to further describe the importance of classifying yogurts as an UPF, considering their Ca and free sugar content. We assessed the correlation between Ca (mg/d) from UPF and the percentage of total energy from (1) energy from total free sugar and (2) free sugar from UPF. We also calculated the contribution of all foods to the variability in free sugar and Ca intakes using stepwise regression analyses.
In sensitivity analyses, we considered other potentially controversial items of the KIDMED index such as number 9, 13 and 15 (Box 2). We calculated the percentage of UPF included in those items and corrected the original score of each participant taking into account that percentage. Therefore, the higher the proportion of MPF or processed foods, the lower the modification of the original score. On the other hand, when the proportion of UPF included in those items of the KIDMED index was high, the original score of each participant was more severely penalised.
We considered P values lower than 0·05 to be statistically significant. Analyses were performed using STATA version 12.0 (StataCorp).
Results
We included in our analyses 386 participants, 52·0 % boys, with mean age 5·3 (sd 1·0) years old. Table 1 shows participants’ main characteristics overall and by sex. Girls showed higher BMI z-score (0·2 (sd 1·1)) and lower physical activity (32·7 (sd 21·0)) than boys (–0·1 (sd 1·0) and 46·6 (sd 32·8), respectively). Although most participants had a normal weight status, we observed significant differences by sex, with a higher percentage of girls being overweight or obese (18·5 v. 9·7 %). Most participants (74·4 %) reported moderate adherence to the MedDiet (KIDMED: 4–7 points). Mean energy intake was 2216 (sd 489·6) [9272 kJ/d (sd 2048)] and mean percentages of energy from unprocessed food or MPF, processed culinary ingredients, processed foods and UPF were 47·5, 10·3, 10·0 and 32·2 %, respectively. Between-sex differences were neither observed for adherence to the MedDiet, TEI, nor the percentage of energy from food groups by NOVA classification.
Table 1 Baseline main characteristics of the 386 participants in the SENDO project 2015–2018†
† P-values were obtained with Student’s t-test for quantitative variables and χ 2 test for qualitative variables.
‡ To convert energy values from kcal to kJ, multiply it by 4·183.
*P < 0·05, **P < 0·01, ***P < 0·001.
The contribution of each food item and each food group to the TEI (%TEI), overall and by level of adherence to the MedDiet, is shown in Table 2. Higher adherence to the MedDiet was associated with higher energy intake from unprocessed food or MPF (P < 0·01) and lower energy intake from UPF (P < 0·001). Participants in the highest category of the KIDMED score reported higher consumption of fruit, yogurt, vegetable, rice, nuts, fruit juices, processed cheese and cured ham but a lower consumption of ultra-processed meat, chocolate, ready-to-eat meals, snacks and candies.
Table 2 Contribution to total energy intake (%) of each food group according to its processing degree by adherence to the Mediterranean dietary pattern of the participants in the SENDO project 2015–2018
† To convert to kJ/person, multiply kcal/person values by 4·184.
‡ Viscera, seafood.
§ Sugary chocolate drinks and products.
‖ Sweetened petit suisse, fermented milk, custard.
¶ Gelatine, popcorn and nougat.
Linear trend test. P-values: *P < 0·05, **P < 0·01, ***P < 0·001.
We found a significant inverse association between adherence to the MedDiet and the percentage of energy from UPF (Table 3). Two additional points in the KIDMED score were associated with a 2·8 % (95 % CI 1·9, 3·7) lower contribution of UPF to the TEI in the crude model. The difference was even higher after adjusting for potential confounders (difference 3·1 % (95 % CI 2·1, 4·0)). Furthermore, compared with children in the lowest category of adherence to the MedDiet, those in the highest category showed 6·6 % (95 % CI 3·2, 10·0) lower contribution of UPF to the TEI in the crude model and 8·5 % (95 % CI 5·2, 11·9) in the multivariable adjusted model. A significant linear trend was observed for the contribution of UPF to the TEI across the categories of adherence to the MedDiet (P < 0·0001). Similar results were found when yogurt was moved from the group of unprocessed food or MPF to the group of UPF.
Table 3 Change (β coefficient and 95 % CI) in the percentage of total energy intake from ultra-processed foods associated with higher adherence to the Mediterranean dietary pattern of the participants in the SENDO project 2015–2018*
* Model 1: Change associated with a two-point increase in the KIDMED score (continuous), with yogurts classified as minimally processed foods. Model 2: Change associated with a two-point increase in the KIDMED score (continuous), with yogurts classified as UPF. Model 3: Change associated with a higher adherence to the Mediterranean dietary pattern with KIDMED index as a categorical variable and yogurts classified as minimally processed foods. Model 4: Change associated with a higher adherence to the Mediterranean dietary pattern with KIDMED index as a categorical variable and yogurts classified as UPF.
† Generalised estimating equation adjusted for sex, age (continuous), total energy intake (quintile), physical activity (quintile), breast-feeding (dichotomous), mother’s age (continuous), maternal education (categorical), paternal education (categorical), family history of obesity (dichotomous) and accounting for intra-cluster correlation between siblings.
In sensitivity analyses, we found that the proportions of cereals, milk and cheese/yogurt that could be considered as UPF were 33, 36 and 99 % (considering yogurts as UPF). After the penalisation, the mean score in the KIDMED index decreased to 5·2 (sd 1·5; P < 0·0001) and the proportion of children with moderate and low adherence to the MedDiet increased to 76·30 and 21·10 %, respectively (data not shown in tables). In this scenario, considering the KIDMED index score as both a quantitative and categorical variable, higher adherence to the MedDiet resulted in a slightly lower contribution of UPF to TEI (online supplementary material, Supplemental Table 1).
In further analyses, considering yogurt as an UPF, we found that free sugar contribution to TEI was 11·0 %, with 9·4 % of it coming from UPF alone. In this context, we observed a direct and moderate correlation between Ca from UPF and both total free sugar (r = 0·57) and free sugar from UPF (r = 0·68) (Fig. 1). Furthermore, 71·6 % of the variability in free sugar intake was explained by the variability in the consumption of UPF, with sweetened dairy products being the most important contributor to that variability (24·3 %), closely followed by yogurts (16·3 % change in R 2). However, the variability in the consumption of sweetened dairy products and yogurt only explained the 5·2 and 8·6 %, respectively, of the variability in Ca intake from UPF (Table 4).
Fig. 1 Pearson’s correlation (r) between Ca (mg/d) from UPF and percentage of total energy intake (%TEI) from total free sugar (mean 11 %) and free sugar from ultra-processed foods (mean = 9·4 %) in the SENDO project 2015–2018
Table 4 Contribution of the ultra-processed foods to the intake of total free sugar and Ca of the participants in the SENDO project 2015–2018*
* Cumulative R 2 values were determined with the use of nested regression analyses after a stepwise selection.
† The order of stepwise analysis of Ca: All unprocessed or minimally processed foods, yoghurt, UPF cheese (R 2 = 7·69), sweetened dairy products, all processed culinary ingredients and processed foods, sugar-sweetened beverages, chocolate.
‡ Sweetened petit suisse, fermented milk, custard.
§ Sweetened yogurts.
‖ Sugary chocolate drinks and products.
Discussion
In the present study of 386 Spanish pre-schoolers, we found that children with higher adherence to the MedDiet reported a healthier dietary profile, with higher consumption of unprocessed food or MPF and processed culinary ingredients, which together made up 50·6 % of energy intake. This suggests that children with higher adherence to the traditional MedDiet obtained most of their energy content from handmade meals, in which the preparation of MPF is combined with culinary ingredients, such as salt, table sugar and oils or animal fats(Reference Monteiro, Cannon and Levy8,Reference Louzada, Martins and Canella33) . Our results showed that compared with low adherence, high adherence to the MedDiet was associated with an 8·5 % (95 % CI 5·2, 11·9) decrease in energy intake from UPF, after adjusting for potential confounders and accounting for intra-cluster correlations between siblings.
The industrialisation of dietary patterns has led to a higher intake of UPF and consequently a higher intake of free sugar, which has been associated with an increased risk of CVD, adiposity and dyslipidemia(Reference Vos, Kaar and Welsh34). In our sample, free sugar accounted for 11·0 % of TEI, which is above the 5–10 % upper threshold recommended by the WHO(24). 71·6 % of the free sugar intake in our sample came from UPF. These findings agree with the last Spanish Household Budget Survey, which estimated that 13·0 % of the TEI of Spanish households came from free sugar and of which 80·4 % came from UPF(Reference Latasa, Louzada and Steele5). Furthermore, data from the USA indicated free sugar accounted for 13·7 % of TEI (Reference Steele, Baraldi and Laura35), with 89·7 % coming from UPF.
Yogurt represents an important food item in children’s diet because many families consider it a main source of Ca in their diet. However, a recent study with Spanish schoolchildren found that the consumption of dairy products was insufficient to impact total Ca intake(Reference Rubio-López, Llopis-González and Picó36). To further investigate the role of yogurts in children’s diet, we presented two scenarios: (1) yogurts were classified as unprocessed food or MPF (unsweetened) or (2) yogurts were classified as UPF (sweetened). In the first scenario, we found high adherence to the MedDiet was associated with an 8·5 % lower energy intake from UPF. However, in the second scenario, the reduction was slightly lower (8·0 %). We favoured the second scenario and, based on the correlation and regression analyses (Fig. 1, Table 4), concluded that the contribution of sweetened dairy products (including yogurts) to the total variability in Ca intake should be confronted with their contribution to the variability in total and free sugar intake.
Regardless of the classification of yogurts, most of the children in our study reported moderate adherence to the MedDiet, and the mean energy intake from UPF was 32·2 %. Previous studies in Spanish population found that, in the period between 1990 and 2010, the contribution of UPF to the total household food increased from 11·0 to 31·7 %(Reference Latasa, Louzada and Steele5), and adherence to the MedDiet decreased(Reference Bach-Faig, Fuentes-Bol and Ramos37). In Europe, outside the Mediterranean region, the contribution of UPF to household availability of food ranges from 10·2 % in Portugal to the alarming peak of 51 % in the United Kingdom(Reference Monteiro, Moubarac and Levy38), where it has also impacted the nutritional quality of the whole nation(Reference Cornwell, Villamor and Mora-Plazas10,Reference Louzada ML da, Ricardo and Steele11,Reference Vandevijvere, De Ridder and Fiolet39) . This change in the dietary pattern may be key to explaining the growing prevalence of childhood obesity and obesity-related complications(Reference Costa, Rauber and Leffa40,Reference Rauber, Campagnolo and Hoffman41) . The association between the consumption of UPF and obesity has been reported in a prospective cohort of Spanish adults(Reference Mendonça, Pimenta and Gea42), but the evidence in pediatric populations is still scarce. Nevertheless, the transformation of the food environment that followed industrialisation is becoming more and more evident as with UPF dominate the food market and replace, more and more, fresh and MPF. Since young generations will be exposed to this food environment for a longer period of time, it is logical to expect the impact on their health to be greater.
In the sensitivity analysis, we used a more conservative KIDMED index, since we penalised the score in those items that, under our consideration, included UPF (items 9, 13 and 15). Using that corrected score, we found that the magnitude of the association between the adherence to the MedDiet and the contribution of UPF to TEI was even higher (more negative). These results not only reinforce our hypothesis but also point out the need to update the KIDMED index to make it more suitable for capturing true adherence to the traditional MedDiet of children and adolescents.
We have previously published that higher adherence to the MedDiet in children was directly associated with parental healthy eating habits but not with parental nutritional knowledge(Reference Romanos-Nanclares, Zazpe and Santiago21). These findings suggest that, beyond individual knowledge, several factors that impact an individual’s food choices must be considered. The regulation of the production, marketing and advertising of UPF should be a priority for public health policies. Strategies such as front of package labelling with clear information on sugar content(Reference Arrúa, MacHín and Curutchet43–Reference Neal, Crino and Dunford45) or sweetened beverages taxation could be helpful in improving individual choices(Reference Backholer, Sarink and Beauchamp46,Reference Ng, Rivera and Popkin47) .
Our study has several strengths. First, to the best of our knowledge, no other study has associated the MedDiet with the consumption of UPF in children. Second, we have identified that the KIDMED, one of the most extensive indexes for assessing children’s adherence to the MedDiet, might present some drawbacks related to insufficient information on the food processing type. Third, in all analyses, we accounted for intra-cluster correlation between siblings, which is a common limitation of cohort studies in children. Lastly, our results are consistent in a sensitivity analysis aimed at evaluating whether the classification of yogurts would impact the magnitude of the observed difference.
Nevertheless, we must acknowledge some limitations as well. First, a 24-h recall is better than a FFQ for estimating usual intake. As a consequence, food consumption in our study may be overestimated(Reference Cade, Thompson and Burley48,Reference Steinemann, Grize and Ziesemer49) . Nevertheless, previous studies have concluded that the information provided by FFQs is valid for use in epidemiological research(Reference Vioque, Gimenez-Monzo and Navarrete-Muñoz50) and that self-administration reduces cost and facilitates long-term follow-up. Second, we used self-reported information, which might lead to measurement errors. However, since it is unlikely that misclassification of UPF consumption was associated with the adherence to the MedDiet, the most probable classification bias is non-differential, which would bias the estimate towards the null. Third, FFQ are not expected to collect information about food processing; thus, misclassification of some food items cannot be discarded. However, to minimise misclassification bias, food classification was performed by two independent researchers and disagreements were solved by consensus. We also acknowledge that our sample was homogeneous, with a large proportion of participants being highly educated and white families. Although this factor may hamper the generalisability of our results, it also has some benefits, such as higher validity of the self-reported information and the reduction of potential confounding by socio-economic variables. Finally, we used a cross-sectional design; therefore, prospective studies with large sample size and adequate retention rates are needed before causality can be inferred.
Conclusion
Our study provides evidence that higher adherence to MedDiet is associated with a significantly lower percentage of energy intake from UPF. The consumption of unprocessed food and MPF (‘real foods’) should be encouraged as a strategy to regain traditional dietary patterns. Moreover, Spain should promote public health strategies that have been successful in reducing the consumption of UPF such as the regulation of television advertising content during children’s programmes, the implementation of a user-friendly nutritional front labelling, the taxation of sugar-sweetened beverages and the reduction of UPF vending machines in school areas.
Acknowledgements
Acknowledgements: None. Financial support: The support was offered in the form of a scholarship by the Coordination for the Improvement of Higher Education Personnel Foundation – CAPES, Ministry of Education of Brazil, Brazil (grant numbers 88881.187964/2018-01). Conflict of interest: None. Authorship: B.R.S.R. provided specific input on the categorisation of foods, analysed the data and drafted the manuscript; A.R.-C. contributed to the categorisation of foods and analysis; A.R.-N. and E.C. collaborated in data collection; M.Á.M.-G. and K.B.F.B. contributed to the analysis and interpretation of the results and N.M.C. designed the study, coordinated data collection and supervised the analyses. All authors critically reviewed and commented on the manuscript. Ethics of human subject participation: This study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving research study participants were approved by the Clinical Research Ethics Committee of the Government of Navarra (Pyto2016/122). Written informed consent was obtained from all subjects.
Supplementary material
For supplementary material accompanying this paper visit https://doi.org/10.1017/S1368980020001524
