1. Introduction
On December 2019, an outbreak of pneumonia of then unknown etiology emerged in Wuhan City, Hubei Province in China, alerting the medical and scientific communities [
1]. The causal agent was later identified in a new betacoronavirus called SARS-CoV-2, which can affect the lower respiratory tract and provoke bilateral pneumonia in humans [
1]. This pathology—termed COVID-19 by the World Health Organization (WHO)—infected and killed thousands of people throughout the world; extraordinary measures have been taken in most countries, including Spain, Italy, Brazil, Chile, and Colombia. One of the containment measures was the total confinement of the population in their homes, also known as lockdown. This led to the disruption of most daily activities [
2]. Different governments took different measures, yet all promulgated lockdown policies. On 9 March 2020, a national quarantine was imposed for Italy. A state of alarm and national lockdown was imposed on 14 March in Spain. A nationwide quarantine started in Colombia on 24 March 2020. On 27 March, Brazil announced a temporary ban on foreign air travelers and most state governors have imposed isolation policies. No national lockdown has been established in Chile, but some communities and urban areas did declare a mandatory quarantine at different times. However, on 16 March 2020, schools were closed in that country too (
Supplementary Materials Table S1).
Confinement influences lifestyle, especially diet and physical activity. The World Health Organization and the Spanish Academy of Nutrition and Dietetics (2020) indicate that a healthy diet can help in the prevention and treatment of the disease [
3]. Thus, recommendations have been published for food and nutrition during the period of confinement of the population, because there is a close relationship between the quality of a population’s food and its health [
4]. Adequate nutrition is considered a potential factor for health in the early stages of life and adolescence [
5]. At this stage, i.e., the transition period from childhood to adulthood, it is essential to acquire good eating behaviors that can concomitantly influence current health status and predisposition to diseases, e.g., obesity, diabetes, cardiovascular pathologies, etc., in adulthood. It is worth mentioning that the WHO implements and maintains health risk factor monitoring systems in adolescents [
6].
It should be noted that, during confinement, it could become difficult to shop for fresh groceries and shortages of certain food products might happen. As recognized by The Food and Agriculture Organization (FAO), the COVID-19 pandemic has caused disruptions in food chains around the world, affecting both supply and demand [
7]. Further, COVID-19 has made visible and magnified social inequalities, with the poorest families being the most affected ones [
7].
On the other hand, there is the possibility that closer contact with family members and more home cooking due to COVID-19 confinement could teach adolescents skills that could improve their nutrition knowledge and behaviors, as several studies have indeed reported [
8,
9].
Therefore, in view of the current pandemic—when the population is suffering from social isolation—it is necessary to carry out research on the influence of this confinement on the quality of adolescents’ diet, considering some markers of healthy food intake. This could help public health authorities shape their recommendations, in terms of nutrition policies for adolescents, for future lockdown policies. Indeed, lifestyle lessons from the COVID-19 pandemic should prepare the whole population for the next one [
10].
We aimed to assess the effects of COVID-19-induced confinement policies on self-reported nutritional habit modifications in adolescents from the five above-mentioned countries compared with their usual diet and with the dietary guidelines. Moreover, we aimed to identify potential variables that may have influenced this change.
2. Materials and Methods
2.1. Participants
This project was undertaken between 17 April 2020 and 25 May 2020. The target population was adolescents aged 10 to 19 years from several regions of Spain, Italy, Brazil, Colombia, and Chile (
Supplementary Materials Table S2). The participants consented to participate in the study, with a digital informed consent form.
2.2. Study Design
This cross-sectional study used data collected via an anonymous online questionnaire consisting of more than 30 questions about dietary habits during COVID-19 confinement and the previous period. We distributed the questionnaire via social media, e.g., Twitter, WhatsApp or others (see below). In addition, researchers involved in this project distributed the survey to work colleagues.
Dietary practices were evaluated using a standardized adolescent questionnaire, the National School Health Survey–PeNSE; Pesquisa Nacional de Saúde do Escolar [
11], which was slightly modified. Data collection was performed through a questionnaire divided into modules: sociodemographic and family features and dietary practices before and during confinement. The adolescent recorded the number of days on which they consumed the following foods or food groups during the week before confinement (BEFORE) and one week during confinement (COVID19): legumes; vegetables; fruit; sweet food; fried food (including packaged potatoes); processed meat (burger, sausage, mortadella, salami, ham, chicken nuggets, or sausages); sugar-sweetened beverages (SSB), and fast food. The PeNSE survey allows us to compare international indicators, especially those of the Global School-Based Student Health Survey [
12], developed by the WHO, used in more than 90 countries around the world.
2.3. Data Collection
Data collection was carried out through a structured questionnaire created in Google Forms (Google LLC, Menlo Park, CA, USA). The questionnaire was divided into modules by subject: sociodemographic characteristics, dietary and lifestyle practices. The invitation to participate in the survey was made by social media (Facebook, Instagram and WhatsApp) or by e-mail to municipal authorities’ parents. The flow chart of participants of the study is depicted in
Supplementary Figure S1.
2.4. Data Analysis
Initially, we compared the average intake of different food groups among the participants during COVID-19 confinement (COVID19) versus the previous period (BEFORE) by paired two-way Student’s t-test. The comparison of mean intake of different food groups during COVID-19 confinement classified by sociodemographic and family variables was assessed by two-way ANOVA. The independent categorical variables in Table of percentage of adolescents that maintain adequate food intake according to dietary guidelines by sociodemographic and familiar variables were assessed by chi-square test. A 95% confidence interval (95%CI) was adopted. To do this, two variables were created: a variable quantifying servings of legume, fruit, vegetables, fried food, sugary drinks, processed meat, and fast food intake per week, with seven categories (once, two, three, four, five, six and seven times per week) (this was the more important variable of this study); and a binary variable indicating if these adolescents met the WHO recommended diet during self-quarantine or longer home stays (yes/no). Socio-demographic variables collected were categorized as: gender: female and male; age: ≤14 years, 15–16 years and ≥17 years; number of people living at home: ≤3 people, 4–6 people and ≥7 people; watching TV during mealtimes: always, sometimes and never; and maternal education: none, primary, secondary, professional formation and complete university. A significance level of p < 0.05 was applied to all statistical analyses. GraphPad Prism 8 (version 8.3.0; Graph Pad Software Inc. San Diego, CA, USA) was used for all statistical analyses.
2.5. Ethical Approval
Ethical approval was obtained by the appropriate Ethical Committees of each country where the survey was performed. Specifically, by the IMDEA Food Research Ethics Committee in Spain (code IMD: PI-043); by the Ethical Committee of Human Inspired Technology Research Centre-Padova University in Italy (HIT Ethical Committee 33035 22 April 2020); by the Research Ethics Committee of IPPMG–Federal University of Rio de Janeiro in Brazil (approval number: 3,975,744); by the Cartagena committee and the University of Cartagena in Colombia (acta N° 134) and by the University of Concepción School of Medicine Bioethical Committee in Chile (CEBB 646-2020). The study is in accordance with the ethical principles of non-maleficence, beneficence, justice and autonomy, contained in the ethical resolutions of each country, according to the Helsinki declaration. An informed consent form was signed digitally by one of the participants’ guardians before initiating the survey.
4. Conclusions
In conclusion, our findings provide the first description of how the COVID-19 pandemic has modified dietary trends of adolescents from Spain, Italy, Brazil, Colombia, and Chile. These new habits could be acquired and have some later impact on health. Due to confinement, it appears that families had more time to cook and improve eating habits by increasing legume, fruit, and vegetable intake, even though this, apparently, did not increase the overall diet quality. Further, adolescents also exhibited a higher sweet food consumption, likely due to boredom and stress produced by COVID-19 confinement. This study shows the association between gender, country of residence, family members at home, watching TV during mealtimes and maternal education variables with adequate nutrition during COVID-19 confinement. Therefore, it is important to generate future large-scale studies that analyze eating habits to encourage the adoption of healthy diets among adolescents, especially after this period of confinement. Understanding the present adolescent’s nutrition behavior during Covid-19 lockdown will help public health authorities reshape future policies on adolescents’ nutritional recommendations, when new pandemics arrive and lockdown policies are implemented.