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Both parental education and the food environment influence dietary intake and may therefore contribute to childhood obesity.
We aimed to assess the consumption of ultraprocessed foods (UPFs) in a convenience sample of adolescents with obesity and to determine its association with the food educational style of their parent.
This observational study included 24 participants, 12 adolescents (8 boys and 4 girls) aged from 12 to 14 years and their 12 parents, who were followed in a specialized pediatric obesity clinic in the French-speaking part of Switzerland. The adolescents were asked to take a photograph with a smartphone application of all meals and beverages consumed in their daily routine over 14 consecutive days. They evaluated their parent’s food educational style using the Kids’ Child Feeding Questionnaire. The parent who was present at the study visits also completed the Feeding Style Questionnaire. A dietitian analyzed the pictures to extract food group portions and to identify UPFs using the NOVA classification. A nonparametric statistical test was used to investigate associations between UPF intake and food educational style.
Overall, the adolescents had unbalanced dietary habits compared to national recommendations. They consumed an insufficient quantity of vegetables, fruits, dairy products, and starchy foods and an excessive amount of meat portions and sugary and fatty products compared to the current Swiss recommendations. Their consumption of UPFs accounted for 20% of their food intake. All adolescents defined their parent as being restrictive in terms of diet, with a mean parental restriction score of 3.3±SD 0.4 (norm median=2.1). No parent reported a permissive food educational style. A higher intake of UPFs was associated with a lower parental restriction score (
Despite being followed in a specialized pediatric obesity clinic, this small group of adolescents had an unbalanced diet, which included 20% UPFs. The intake of UPFs was lower in participants whose parent was more restrictive, suggesting the importance of parents as role models and to provide adequate food at home.
ClinicalTrials.gov NCT03241121; https://clinicaltrials.gov/ct2/show/NCT03241121
Childhood obesity is a significant public health challenge, with an increasing prevalence worldwide and multiple long-lasting consequences [
In the past decades, the level of food processing has significantly increased [
Both the education and the environment influence dietary intake in general, and in addition, in children, parental education and the food environment provided are crucial. Ellyn Satter [
In this observational study, we aimed to assess the consumption of UPFs in a group of Swiss adolescents with obesity and to determine its association with the food educational style of their parent.
This observational study included adolescents aged 12-14 years who were followed in a specialized pediatric obesity clinic at the Lausanne University Hospital, Lausanne, Switzerland, and one of their parents. The study was an observational nested study of the SwissChronoFood trial [
The families were sent to the pediatric obesity clinic by their pediatrician. At the time of inclusion, the senior dietician (author SB) had followed the adolescents for several months. She invited all adolescents aged 12-14 years who had an appointment at the clinic from January to February 2019 to participate in the study. Of the 62 adolescents aged 12-14 years informed about the study, 37 declined because of a lack of interest or time to attend the study visits and 9 because of a language barrier or the lack of a parent available to attend the study visits (
Recruitment process of adolescents and one of their parents.
Demographic and anthropometric data were collected in the first visit. After 1 week, the dietician had a phone meeting with the adolescents to question them about the use of the smartphone application (explained later) and to encourage them to continue taking pictures conscientiously. At the last visit, the dietitian checked the pictures collected by the smartphone application and performed a 24-hour food recall.
The z score of the body mass index (BMI) according to age was used to define overweight and obesity. According to the World Health Organization [
All adolescents used a smartphone application to take pictures of all consumed food and beverages, except water, over 14 consecutive days. They could annotate each picture with a text description. We compared the food pictures collected by the food application and the 24-hour food recall performed at the second visit. The senior dietician (SB) manually counted the number of food portions consumed each day by each adolescent and estimated the number of servings from each picture. Food items were grouped according to the Swiss food pyramid [
The parental food education style was assessed from the perspectives of both the adolescents and their parent. At the first visit, the adolescents completed the Kids' Child Feeding Questionnaire in a separate room from the accompanying parent [
Although the adolescents were completing the questionnaire in a separate room, the parents answered the Feeding Style Questionnaire, which explores a parent’s perspective in eight problematic situations (eg, your child wants to eat pasta, when you intended to cook vegetables) and is also validated in French [
Data are reported as the mean±SD, unless stated otherwise. Nonparametric tests were used due to the small sample size. We compared the rank-sum test between UPF intake and food educational style (restriction, pressure to eat, and authoritarian, authoritative, and permissive dimensions) with the Wilcoxon-Mann-Whitney test. For analysis of the perceived parental dietary restriction, we defined groups of low restriction and high restriction using the median value of 3.25.
We included 12 adolescents, 8 boys and 4 girls, aged 12-14 years and 12 parents, 8 mothers and 4 fathers, aged 37-55 years. At the time of the study, the adolescents had been followed in the specialized pediatric obesity clinic for several months. Of the 12 adolescents, 11 (91.6%) were obese and 1 (8.4%) had lost weight, thus changing from the obese category to the overweight category. Most parents were overweight or obese (n=11), and 10 (83.3%) worked at an activity level of ≥70%, except for 2 (16.7%) parents on disability insurance. Five of the included parents (42%) were separated, but the adolescents spent almost all of their time with the parent who was present at the study visits.
Characteristics of adolescents and parents.
Characteristics | Value | |
|
||
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Number | 12 (4 girls/8 boys) |
|
Age (years) | 13.3±0.6 (12.0-14.3)b |
|
BMIa (kg/m2) | 30.0±2.6 (24.9-33.7)b |
|
BMI (z score)c | 2.7±0.4 (1.9-3.4)b |
|
||
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Number | 12 (8 mothers/4 fathers) |
|
Age (years) | 45.3±4.6 (37.0-55.0)b |
|
BMI (kg/m2) | 29.1±3.2 (23.2-35.8)b |
|
Married or in a relationship with the other parent (%) | 58.3 |
|
Time spent with child (%) | 97.9±7.0 (75-100)b |
|
Training after compulsory school (years) | 3.2±2.9 (0-7)b |
|
Professional activity rate (%) | 70.0±30.0 (0-100)b |
aBMI: body mass index.
bData are presented as the mean±SD (minimum-maximum range), unless stated otherwise.
cObesity in adolescents was defined as a z score of BMI>2.
Overall, the adolescents had unbalanced dietary habits compared to national recommendations (
Comparison of food consumption with the Swiss recommended daily portions [
Food groups | Number of portions per day (mean±SD) | Swiss national recommendations for 13-14-year-old adolescents (n) |
Fruita | 0.4±0.3 | 2 |
Vegetables | 1.2±0.6 | 3 |
Starchy foods | 2.5±0.8 | 4.5 |
Meat, fish, egg, tofu | 1.4±0.4 | 1 |
Dairy productsb | 1.1±0.3 | 3 |
Sugary productsc | 1.2±0.7 | 1 |
Fatty productsd | 1.3±0.7 | 1 |
Sweet beverages | 0.2±0.3 | 0 |
UPFe intake | 1.6±0.6 | —f |
UPF portions/total number of food portions (%) | 20.9±3.6 | — |
aIncluding a maximum of 1 glass of fruit juice per day and a maximum of 1 fruit compote per day.
bIncluding milk, yogurt, cheese, and milk drinks.
cIncluding jam, honey, chocolate, cookies, cakes, fruit yogurt, candies, sodas, ketchup, sweet sauce for nems.
dIncluding sausages, crisps, breaded meat, chocolate, cookies, raclette, fondue, fat-containing sauces (carbonara, mayonnaise), lasagna, and pizza.
eUPF: ultraprocessed food (includes industrial prepackaged snacks, sweets, commercial biscuits, chips, sausages, ham, sodas, filled croissants, ravioli, tortellinis, spätzlis, fajitas, ketchup, mayonnaise, sweet and sour sauce, nems, milk drinks [eg, Danao®, Actimel®], toasted bread, pizza, dessert cream, and chocolate spread).
fNo Swiss recommendations for UPF food group
According to the Kids’ Child Feeding Questionnaire [
(A) Food educational styles perceived by the adolescents. Results of the Kids’ Child Feeding Questionnaire [
The Feeding Style Questionnaire completed by the 12 parents showed that the most common dietary educational style was the authoritative style, with a mean score of 3.05±0.51, followed by the authoritarian style (2.82±0.57). The permissive style had the lowest score (1.67±0.52). The authoritative style was predominant in seven parents, and the authoritarian style was predominant in five parents (
When analyzing the adolescents’ dietary intake and the respective parent’s food educational styles, we found a significant association between the proportion of UPF intake compared to the total food intake and the level of parental dietary restriction (
Consumption of UPFs according to the parental dietary restriction perceived by the adolescents. Association between the proportion of UPF intake out of the total food intake and the level of parental dietary restriction (rank-sum
In this observational study conducted in the French-speaking part of Switzerland, the small group of adolescents with long-standing obesity had unbalanced eating habits, including excessive UPF consumption, despite being followed in a specialized pediatric obesity clinic. The adolescents perceived their parent as more restrictive than the norm, and none of the parents had a permissive food educational style. Lower UPF consumption was associated with a higher parental dietary restriction.
The reported diet was unbalanced, including 0.4 portions of fruit per day instead of the 2 portions recommended by the Swiss national recommendations [
In this study, UPF consumption was high, with 1.6 portions consumed per day, representing 20% of the foods consumed.
The comparison of these findings with other studies is limited, as UPF consumption is often reported as a percentage of daily energy intake and not in terms of portions per day. A study in adults found that UPFs reached an average 26% of daily energy intake, ranging from 10% to 50%, depending on the 19 European countries assessed [
UPFs contribute to an unbalanced diet due to their low nutritional quality, including a high content of added sugars, fats, or additives and a low content of fiber. The lack of prospective studies precludes a definitive conclusion on the causal relationship between UPF consumption and obesity [
A permissive food educational style is recognized as promoting obesity [
The main limitation of this study was the limited sample size, which included 12 adolescents and 12 parents. We contacted 62 adolescents followed in our pediatric obesity clinic and their parent to participate in the study. A total of 50 refused to participate, 37 due to a lack of interest or time and 9 due to a language barrier or the lack of a parent available to attend study visits; in addition, 4 families had to cancel their participation before the first visit. This shows the difficulty of recruiting this population in dietary studies involving longitudinal data collection. This could have led to a type I error, but our results are mostly exploratory and will help future studies in the form of preliminary results for sample size calculation and new hypotheses generation. Other limitations were the low response rate and the potential social desirability of participants who would only take pictures of the food they wished to show. Although the long duration of the data collection period provided detailed information about dietary habits and was a strength of this study, it might also be a limitation. Indeed, 2 weeks might have been too long for adolescents, leading to potential missing data, as shown by the comparison with the 24-hour food recall. The 24-hour food recall showed the consumption of more foods, such as highly processed foods, which accounted for 26% of the foods in the recall instead of 20% with the smartphone application. The data were collected between January and March, which might have affected the availability of fresh products. However, the availability and price of fresh products in Switzerland do not differ widely between seasons. Finally, the studied adolescents were followed in a specialized pediatric obesity clinic in the French-speaking part of Switzerland; thus, our findings may not be applicable to adolescent populations in other parts of the world or followed in other clinical settings. The main strengths of the study were the review of UPF consumption by a senior dietitian, which allowed an estimation of the number of UPFs compared to other foods; the use of a smartphone application to take food pictures; and the assessment of parental feeding practices, perceived by both the adolescents themselves and one of their parents. Our study relied on a smartphone application to collect data on eating behavior and food content. This is consistent with the current trend in remote data collection from patients, as recently demonstrated during the COVID-19 pandemic [
In our study, the small group of adolescents had unbalanced eating habits despite being in a treatment program. They all defined their parent as being restrictive in terms of diet, and no parent reported a permissive food educational style. The consumption of UPFs was lower among adolescents whose parent was more restrictive, suggesting that adolescents have fewer opportunities to eat when some degree of restriction is applied by their parent. The parent’s food educational style and food choices available at home, including UPFs, may be a key target for personalized nutritional interventions in adolescents with obesity.
body mass index
principal investigator
Swiss Nutrition Society
ultraprocessed food
The authors wish to thank the study volunteers for their participation, the research team involved in data management, and the clinicians from the pediatric obesity clinic who referred the patients, especially Dr M Hauschild, Dr T Bouthors, Dr I Ruiz, and S Petter. This study was performed as the master thesis of SB, supervised by CJC and SBDT. This study was part of the SwissChronoFood trial (ClinicalTrials.gov registry no. NCT03241121; principal investigator [PI], THC) funded by the Swiss National Science Foundation (grant no. PZ00P3-167826 to THC) and the Swiss Society of Endocrinology and Diabetes (2017 Young Investigator prize to THC). THC’s research is also funded by the Leenaards Foundation, the Vontobel Foundation, and the Medical Directorate of the Geneva University Hospitals, Switzerland.
SB, SBDT, CJC, and THC contributed to the design of the study; SB and THC collected the data; SB, THC, SBDT, and CJC performed data analysis and interpretation; SB drafted the manuscript; SB, SBDT, CJC, and THC contributed substantially to the revision of the final manuscript; and SB and THC had full access to the dataset and are guarantors of the data integrity. The datasets used during this study are available from the corresponding author upon reasonable request.
The authors declare that they have no potential competing interest.