From MED4Youth, one of the main objectives is to demonstrate that a Mediterranean diet enriched with products typical of the Mediterranean, such as pomegranate, chickpeas/hummus, nuts and sourdough bread, is more effective in maintaining an optimal weight and healthy habits than a conventional low-fat diet among adolescents.
In this sense, the an interventional nutrition study was carried out to assess and generate evidence of the benefits of the Mediterranean Diet to tackle youth obesity and associated comorbidities in adolescents of three Mediterranean countries (Spain, Italy and Portugal).
We interviewed Eurecat, University of Coimbra and University of Parma team carrying out the study to learn more about the research conducted, the study phases and the volunteers enrolled.
How was the study designed?
As part of the MED4Youth project, a single-blind, randomized, parallel-group and controlled multicentre study was proposed. It involved adolescents with overweight or obesity (>90th percentile) which were randomly allocated to receive an energy-restricted Mediterranean Diet or a traditional low-fat diet as control diet.
The Mediterranean Diet group included Mediterranean foods with satiate characteristics such as sourdough bread, chickpea/hummus, mix of natural nuts, and pomegranate juice. Both dietary interventions were combined with an educational web-application to increase engagement and knowledge of adolescents through a “learning-through-playing” approach, using educational materials and games.
To assess the efficacy of the intervention, anthropometric and biochemical parameters, as well as adherence to the Mediterranean Diet, physical activity, food frequency, sociodemographic, and quality of life questionnaires were evaluated during different in-person visits performed at the research centres. Additionally, omics technologies and a system biology approach were applied to elucidate whether the Mediterranean Diet can shape the gut microbiota and gut-derived metabolites and unravel the mechanisms by which Mediterranean Diet exerts its beneficial effects against youth obesity.
How many people are participating in the study?
Overall, including the studies carried out in Spain, Portugal and Italy, a total of 148 adolescents were recruited and randomized in one of the intervention groups (Mediterranean Diet or control group). So far, 110 adolescents have finished the four-months of treatment.
In Spain, 42 participating adolescents have been assigned in a balanced manner in the Mediterranean Diet group and the low-fat diet group. In Portugal, the clinicians have pre-selected around 60 potential participants. From those, 26 participants were enrolled, and 22 of them have concluded the intervention period. Finally, in Italy, 80 children and adolescents with overweight or obesity were recruited, 54 of them have completed the intervention period (4 month) and 43 attended also the follow-up visits (5 will finish in the upcoming weeks).
Which requirements participants have to meet?
To be included in the MED4Youth study, participants had to be between 11 and 17 years old, had access to a mobile phone, computer and/or tablet with Internet and had to meet the following inclusion and exclusion criteria:
- Inclusion criteria: subjects were eligible for enrolment into the study if they were boys and girls defined as an age-and sex-specific BMI in the 95th percentile or greater or having great overweight (age-and sex-specific BMI in the ≥90th to <95th percentile). To be enrolled volunteers’ parents or holders of parental responsibility had to provide written informed consent.
- Exclusion criteria: participants had been excluded if they suffer diabetes and other metabolic, endocrine and chronic disorders; intake of antibiotics, drug, probiotics or nutritional supplements in the last month; prescribed medicine to control hypertension, inflammation or dyslipidaemia; following a prescribed diet for any reason, including weight loss in the last 3 months; following a religion-restricted diet; and having allergies or food intolerances to any of the study products.
Can you explain a bit on how were the participants recruited?
Eurecat: The recruitment in Spain was conducted through various channels, including the communication channels of the Technology Centre of Catalonia – Eurecat, leader of the Spanish study, the MED4Youth project’s website and Social Media accounts, press releases sent to general and specialised media outlets, TikTok videos, and different posters, flyers and brochures displayed in Catalan healthcare centres. Additionally, professionals in the healthcare field, such as dietitians – nutritionists working in hospitals and public health clinics, were actively involved in the recruitment process.
Furthermore, informative talks were held at healthcare centres to introduce the study to healthcare professionals, and local television interviews were conducted to increase the study’s visibility. These additional initiatives helped expand the dissemination of the study and engage more adolescents interested in participating.
University of Coimbra: at the beginning of the study, the clinicians from the Obesity Service and the Cardiovascular Service from the Paediatric Hospital of Coimbra Hospital and University Centre pre-selected the potential participants by the inclusion and exclusion criteria. After that, clinicians contacted the parents of the potential participants to ask for permission to be contacted by the research team.
Afterwards, the research team contacted the potential participants to explain the study and to assess if both the adolescents and the parents wanted to participate and if they could be committed to the study. All the participants that accepted to participate have been given informed consent that has been read and signed by the legal tutors.
University of Parma: the recruitment was possible thanks to the collaboration between the Human Nutrition Unit of the University of Parma and the Unit of Pediatrics of the University Hospital of Parma.
Paediatricians pre-selected potential participants checking the inclusion/exclusion criteria of the MED4Youth intervention study of children and adolescents entering the hospital. If a patient met all inclusion criteria, parents were contacted by phone and explained about the intervention study. If they and their child agreed to participate, they were invited at the hospital to receive detailed information about the study procedures and to sign an informed consent
Can you explain a bit about the different phases of the study?
The study consisted of four in-person visits during an intervention’s duration of four months: a preselection visit and three visits during the dietray intervention. After the intervention phase concluded, participants were scheduled for a follow-up visit four months later, resulting in a total study duration of eight months from the beginning to the end.
The first visit served as an informative session where participants were provided with an overview of the study and had the opportunity to address any doubts or concerns. During this visit, both the adolescent participant and their parents were introduced to the study’s app.
If the adolescent met the eligibility criteria, they and their parents were scheduled for a first intervention visit. During the first intervention visit, some biological samples were collected for further analysis, including blood tests, fresh morning urine samples, and stool samples. In this visit, the family was informed whether the adolescent had been assigned to the low-fat diet group or the Mediterranean diet group. They were provided with an individualized meal plan based on the exchange system, which offered flexibility to accommodate the specific needs and preferences of the adolescent. In addition, they were given some instructions on the dietary guidelines they needed to follow during the study.
Between the first intervention visit and the second in-person visit, both the participant and their family received a follow-up phone call to address any questions or concerns related to the study. Then, they attended another in-person follow-up visit (at 2 months after the beginning of the intervention), during which the 3-day dietary record, anthropometric changes, and study questionnaires were evaluated.
The final intervention visit took place at the study centre (after 4 months of the beginning of the intervention), and the participant’s dietary record and anthropometric measurements were evaluated again, as well as the biological samples. The intervention phase concluded at this visit, and the participant was scheduled for a follow-up visit four months later to assess their adherence to the proposed diet. This last follow-up visit focused on evaluating the 3-day dietary record, study questionnaires, and anthropometric measurements.