The aims of the study were to assess the effects of the brand when snacking in children 6-11 years old and to evaluate the effect of different levels of brand awareness on children’s intake. A 3x2 factorial design was adopted, and 96 children were randomized based on their brand awareness scores, assessed using the IBAI instrument and the study was conducted over two experimental sessions. First, 11 snacks were presented to the half of children laying on their own branded packages, whilst to the other half unbranded. In a second afternoon break, on a different day, the condition of branded/unbranded was crossed-over. Children were randomized in three groups based on combinations of concomitant TV and advertising exposure. Caloric intake (Kcal) of snacks eaten during sessions was taken as the main study outcome. No significant differences in energy intake were recorded according to brand visibility, both in children with high and low brand awareness. Exposure to TV and advertising showed no significant association with energy intake in the different groups and with the likelihood of being a high consumer. The present study suggested that brand visibility did not promote a higher caloric intake in 6-11 years old children during a snacking occasion.
Key words: Food brand, snacking, advertising, ad libitum, brand awareness, caloric intake.
Los objetivos del estudio fueron el evaluar los efectos de las marcas comerciales durante una merienda en niños de entre 6 y 11 años de edad, así como analizar el efecto de diferentes niveles de conciencia de marca en el consumo de los niños. Se utilizó un diseño factorial 3x2, y se asignó al azar a 96 niños según sus puntuaciones de conciencia de marca, que fueron evaluados mediante el instrumento IBAI. El estudio se realizó en dos sesiones experimentales. En primer lugar, se presentaron 11 bocadillos (alimentos), a la mitad de los niños colocando en sus propios paquetes de marca, mientras que a la otra mitad sin marca. En un segundo recreo de la tarde, otro día, se realizó un cruce en la condición de bocadillos de marca y sin marca. Los niños fueron asignados al azar en tres grupos, según combinaciones concomitantes de exposición a la televisión y a pautas publicitarias. La ingesta calórica (Kcal) de bocadillos consumidos durante las sesiones se adoptó como principal resultado del estudio. No se registraron diferencias significativas en el consumo de energía dependiendo de la visibilidad de la marca, ni en los niños con un alto o bajo reconocimiento de marcas. La exposición a la televisión y a la publicidad no mostró una asociación significativa con el consumo de energía en los diferentes grupos y ni con la probabilidad de ser un gran consumidor. El presente estudio sugiere que la visibilidad de las marcas no promueve una mayor ingesta calórica en niños de entre 6 y 11 años de edad en el contexto de una merienda.
Palabras clave: Marca de alimentos, refrigerio- colación, publicidad, a gusto, conocimiento de la marca, ingesta calórica.
Unit of Biostatistics, Epidemiology and Public Health, Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Italy. ZETA Research Ltd, Trieste, Italy. Department of Health Sciences, San Paolo Hospital, Pediatric Clinic, University of Milano, Italy. Department of Clinical and Biological Sciences, University of Torino, Torino, Italy.
The growing prevalence of overweight and obesity in children has gathered an extensive interest from the scientific community (1), shifting from an initial analysis dedicated to assess the present situation and its outcomes toward a broader research targeting potential risk factors involved in its development and maintenance. The increase in childhood and adolescent obesity is leading to adverse health outcomes in the short and in the long term (2, 3), since it is deleterious to individual health, and it also results in a rising cost for the public sector.
The multifactorial network characterizing obesity determinants has frequently been mentioned, in order to broaden research towards a complex scenario taking into account mutual influences and relationships (4, 5). Each node of this net is characterized by different factors, that are modified, switched, and triggered by several macro structures, like genetics, behavior, built and social environment.
Among various factors identified as possible causes for the increase of children’s obesity, television viewing and advertising aimed at children are among the most important factors that have been linked to a reduction in physical activity and an overconsumption of food high in fat and sugar (6, 7).
The mechanism is etiologically grounded on the lower caloric expenditure associated with TV viewing and the increased caloric intake due to TV-generated distraction and snack advertisements. In addition, recent studies have pointed out that, especially in overweight and obese children, preference for high carbohydrate and high fat foods is enhanced in children who are exposed to the greatest amounts of televisual media (8). Experimental studies in adults suggest that focusing attention on watching TV or listening to music while eating may disrupt the ability to regulate energy intake and promote overeating (9, 10). Similar associations were found in children, showing a positive association between TV viewing and childhood obesity (11, 12), but they failed to describe the mechanisms underlying these results. Costa showed the inverse association between screen time and daily consumption of fruits, concluding that the number of television in a household is positively related to BMI in children and adolescents (13).
Literature provides such heterogeneous results referring to the impact of food advertising on children’s food consumption (14). The effect of advertising and its interaction with brand visibility during afternoon snack time has not been yet jointly investigated. Indeed, afternoon snacking has not been very much studied, and its effects, both in terms of nutrient composition and caloric intake, on dinner eating habits or its impact on after-school physical activity are still not entirely known (15).
The primary aim of the present study was to assess the effect of having brands displayed in food packaging on children’s eating behavior during an afternoon snack time. The secondary objective is to evaluate the effect of different levels of brand awareness on children’s intake. By design, TV viewing and brand advertising (displayed both on food package and on TV commercials) were taken into account as potentially intervening factors and balanced during randomization.
The present study was a randomized, 3x2 factorial experimental study. For logistic purposes, the study was organized in three steps: assessment of brand awareness (Step 0), evaluation of brand visibility on children’s caloric intake (Step 1), repetition of Step 1 by crossing over the condition of branded/unbranded visibility (Step 2).
In Step 0 children were selected by means of the score reported from a modified version of the original IBAI questionnaire (16), assessing brand awareness. The total sample was then divided into two groups, one included high brand awareness (characterized by a total scoring ≥40 points) subjects, and the other, a low brand awareness (< 40 points) ones. Furthermore, each group was further assigned to one of three different conditions of TV exposure (No TV, TV, TV + advertising), resulting in 6 factorial combinations. In each category, the resulting 12 children were stratified for brand awareness, age, and gender (Table 1) and finally randomized to brand visibility. In summary, the experimental study developed in Step 1 had a 2x3 (Brand Visibility x TV and advertising exposure) full factorial design, blocked by age (two groups 6-8 and 9-11 years old), by gender (male and female) and by brand awareness. Specifically, the first factor was TV exposure, organized in 3 different levels: no TV exposure, exposure to cartoons, and exposure to cartoons and advertisements. The second factor was the presence of the brand on the snacks given to children, and was organized in two levels: presence of the brand (branded), absence of the brand (unbranded).
Step 2 was carried out equally to Step 1, but inverting the brand level in the two groups (branded snack were given to the subsample that had received an unbranded snack in Step 1, and vice versa).
Ninety-six children between 6 and 11 years of age were selected to have high and low level of brand awareness. Children were recruited as equally distributed by gender and age: fortyeight 6-8-year-olds (24 female) and fortyeight 9-11-year-olds (24 female). Children with cognitive disorders or metabolic diseases or allergies to the products offered during the experimental session were excluded. Parent informed consent was obtained for all children prior to each child’s participation in the study. Children’s participation followed the guidelines and ethics issued by APA (17). Parents were asked not to provide snacks to children in the hours before the experimental sessions.
The sample size of 96 children was computed with reference to an alpha equal to 0.05 and a power of 0.90, which aimed at detecting at least a difference of 20 Kcal of caloric intake (assuming an equal standard deviation in the two groups of approximately 30 Kcal) between the two groups of Brand Visibility in each of the 8 randomization cells (Age x Gender x Brand Awareness).
The two groups of children characterized by different brand awareness (high and low brand awareness) were randomized into 3 groups based on TV and advertising exposure: No TV, TV, TV and advertising. Within the “TV” subgroup, younger children watched a 16 min. episode of Disney© Lion King, while the older ones watched a 16 min. episode of Marvel© Spiderman. The advertising utilized in the third subgroup was embedded within the movies and consisted in 7 spots lasting for 3 minutes, referred to the products that children had on the tray they were facing.
All children were asked to eat ad libitum and to choose the snacks they preferred, being given 16 minutes from their first bite.
All the snacks were weighed with a highprecision balance before and after each session, in order to quantify the amount of snack not eaten, therefore estimating energy intake of each child.
Before the starting of the experimental session, parents were interviewed by the investigators in order to assess demographic parameters, children’s health status, behaviors, frequency of food consumption, food habits, physical activity, daily lifestyle (sleep, TV viewing, after- school care, etc.).
Food images represented in the 30 flash-cards of the IBAI were shown to the children (16), interviewing them on food images’ brand and product names and subsequently on the correct matching of each logo with the right food, between four choices of foods.
At the end, the interviewer asked the child on the specific name of the product. Brand Awareness Scores (IBAI-score) could range from a minimum of 0 to a maximum of 90, with a cutoff set at 40 points which was used to define the two groups: low brand awareness children (<40) and high brand awareness (≥ 40) (16).
At the beginning of the study, every snack was assigned with a specific code and was weighed in order to record these data in the software used for the study. At the end of every session, each snack the child had had was weighed once again in order to calculate the difference in terms of eaten products. All weights were collected by means of an Acculab© precision weighing scale with the capacity of 510g of and 0.1g readability.
A basic exploratory data analysis was performed on the sample and it was reported using the median (I-III quartile) for continuous variables and the percentages (absolute numbers) for categorical variables, as appropriate.
The main analysis has been based on a linear model for caloric intake where the blocking factors (i.e., Gender, Age in two classes according to the randomization procedure, and Brand Awareness) have been forced to stay in the models. Repeated measurements were taken into account using the sandwich estimator of Huber-White (18, 19). Specific investigations on single factor-level effects have been conducted using appropriate linear contrasts.
To check for additional confounding factors, a further model, in addition to the base one has been developed, performing a selection among the candidate variables using the AIC criterion in the backward fashion, still forcing the inclusion of the design variables in the model.
In addition, children were identified as “high consumers” if their caloric intake during the experimental session exceeded the top quartile of the observed distribution. The variables related to the probability of being a high consumer were modelled using a logistic regression model, again using the Huber-White estimator for accounting for repeated measurements, and selected via the AIC criterion in a backward fashion.
The analyses have been performed using the R System (20).
Ninety-six children were assessed using the IBAI questionnaire and were selected to participate to the following phases, equally divided by age (6-8 and 9-11 years), gender, (male and females) and brand awareness score. They were unselected for overweight or obesity. The highest median brand awareness score was retrieved in older males (47.00), while the lowest was measured in the younger female group (26.58).
Sample characteristics (assessed by children questionnaire), in accordance to brand visibility and also to TV exposure (no TV, only TV, TV+advertising) are summarized in Table 1 along with their main characteristics in Table 2.
Comparing the caloric intake of the three groups of children (no TV exposure, only TV
exposure, TV+advertising exposure) when both snacks were branded and unbranded, no significant differences were recorded (Table 3), neither in Step 1 and Step 2. Despite no significant differences, we found out that, in the group of non-visible brand (Step 1), children not exposed to TV presented an intake of 100 kcal higher than those exposed to TV+spot.
Referring to the multivariable model, even after adjustment for potential confounders, we showed no significant association between increased caloric intake and Brand visibility (Table 4).
Figure 2 and Figure 3 report the trends among the two brand awareness groups of total grams intake in children, exposed or not exposed to TV viewing. Children reporting high brand awareness and not exposed to TV showed lower snacks intake when brand was not visible (Figure 2), while children exposed to TV+advertising showed the same snacks intake when both the snacks were branded and unbranded, this probably because of children’s prior preferences towards the snacks, even if we did not investigate them. Additionally, among children with low brand awareness (Figure 3) exposed to TV and TV+advertising, the snack intake was lower when the brand of the snack was visible, this could be related to the fact that TV and TV+ advertising exposure was distracting.
The top quartile of energy intake corresponded to 319 Kcal. This value has been chosen as the cut-off to identify the subgroup of 21 children with higher energy intakes during the experimental session in order to investigate factors associated to higher energy intake in this snacking occasion. Table 5 shows the main characteristics of these “high consumer” children. At the multivariable analysis, no significant association was found for the experimental factor TV (p-value 0.251), Brand Visibility (p-value 0.328) or their interaction (p-value 0.177) with the “high consumer” status. The only variable associated with this status turned out to be the age group of the child. Taking the 6-8 yearold age group as reference, the Odds Ratio (OR) of being a “high consumer” was 0.45 (95% C.I. 0.23-0.89) for older children in the age group 9-11 years.
This study was conducted among a sample of Italian children, where TV advertising it is demonstrated to be similar to those in other countries and in particularly in US. A study published in 2010 (21), comparing food advertising in children’s TV channels of Europe, America, Australia and Asia, demonstrated that food is one of the most advertised products in all the countries involved in the study. However, regarding the type of food advertised, it found differences among Italian and US advertising, showing that fast food and chocolate/confectionary are the most common marketed products in US and Italy respectively. These results are consistent with a study (22) conducted on Italian food advertising for children which revealed that sweets were the products most frequently advertised.
The existence of an association between TV, advertising and risk of being overweight or obese has been evaluated in numerous studies(23-25), obtaining contrasting results. This study aimed at understanding the association between food consumption during snacking times, brand visibility and TV viewing.
With respect to the primary objective of the study, the assessment of the effect of TV viewing and brand advertising, the present study showed no significant effect on total energy intake. The secondary objective was to evaluate the effect of different levels of brand awareness on children’s intake. Similarly to the previous results, no significant association of increased intake was recorded in any of the two brand awareness groups, showing similar trends also for brand and TV exposure.
The results of the present study disagreed with previous research studies, where a positive association was found between advertising and TV viewing and increased energy intake. Halford and colleagues showed that 9-11- yearold (26) and 5-7 year-old (27) children increased their intake of most food types after viewing food adverts, and that the ability to correctly recognize these food adverts was significantly associated with higher food intake following food advert exposure. Similar conclusions were found by Lobstein, that in 2004 stated that the overall findings justified the need for taking precautionary measures to reduce children’s exposure to obesogenic marketing practices (11).
In our study, no significant association between brand visibility and increased caloric intake was found, neither in children with high brandawareness nor in those with low brand-awareness. Children showed a somewhat homogeneous overall intake with a median of 3 snacks per child.
When considering solely the effect of a brand on children’s snack intake, it resulted that if the packages were unbranded, children (in particular, males) tended to consume a higher number of grams of snacks, therefore increasing their caloric intake. These findings were consistent with those in Anschutz’s research, which highlighted in boys an increased susceptibility to food cues in food commercials (28).
As suggested also from the research of Francis, TV viewing could either increase or decrease children’s food intakes (25). Specifically, our study showed that in low awareness children, both TV groups experienced a decreased intake of snack when switching from unbranded towards branded packages. Additionally, children not exposed to TV showed an increased intake with branded snacks in comparison with unbranded snacks. Results were nonetheless not significant. Children seemed to be more prone to eat when they weren’t distracted from any other factor, while TV viewing and brand presence didn’t modify their eating behavior towards a larger request of snacks. These findings were not in line with previous ones, which associated increased snacking behavior with screen time (29).
A multivariable model was used to assess the association between increased caloric intake and other parameters recorded with children questionnaires. In the present sample, confectionery’s habitual consumption appeared to be a protective factor, showing a decreasing effect on overall caloric intake, while being a male and belonging to an older group showed a boosting effect on energy intake.
As a study limitation, it must be taken into consideration that this body of evidence emerges from an experimental study whose results can be extrapolated in the real life with caution. Nevertheless, all efforts were made to minimize biases. All the participating children attended the same school, attending the same meal supply chain and were brought in to the experimental area by their parents, not having eaten any other item before the study. In addition, the ad libitum method allowed us to focus our attention on the children’s satiety point, giving them complete freedom while they were eating the chosen snacks, without any intervention of the interviewer in terms of neither limiting their choices nor highlighting the presence of the brand on the children’s trays. Finally, we did not investigate children’s preferences towards the snacks presented in the study and consequently we could not evaluate the effect of children’s attitudes on energy intake.
The present study failed to prove, in an afternoon snacking occasion, an effect of TV viewing and advertising in children, even when considering the high brand awareness subgroup. While breakfast habits and their effects have been largely investigated, the role of afternoon snacking has been less studied, both from nutritional and from behavioral point of view. However, it’s crucial to widely study this snacking occasion in children, because afternoon snack presents unique characteristics that differentiate it from morning snack, especially in Italian context. While in the morning children have snack at school (which could also provide snacks, such as fruits or yogurt, as in some Italian school facilities implementing project for healthy nutrition), in the afternoon children have snacks usually outside school so they could be exposed to TV viewing (and consequently to TV spot).
Our results might indicate that children’s attitudes to food during afternoon snacking is less modified by exposure to known and common factors like television and advertising. Further research is needed in order to guide health policies aimed at fighting childhood obesity epidemic.
The work has been partially supported by an unrestricted grant from the Italian Ministry of Foreign Affairs under the programs “Programmi di alta rilevanza scientifica e tecnologica” Italia-Messico and Italia-Argentina, and from Prochild ONLUS (Italy).
The study group gratefully acknowledges Ferrero Inc. and Barilla S.p.A. for having provided all the experimental food. All authors declare to not have any conflict of interest.
The authors have no competing interests