Context: Adolescence is a critical developmental stage in which increasing concerns about body image (BI) coincide with the consolidation of dietary habits (DHs). Multiple studies have sought robust associations between BI and DHs to prevent unhealthy behaviors.Objective: The aim of this systematic review was to examine the available literature on the association between BI perception (BIP) and/or satisfaction (BIS) and DHs in adolescents.Data Sources: A search was carried out of 5 electronic databases (PubMed, SciELO, Cochrane, Embase, and PsycInfo) using a combination of keywords (and synonyms) related to adolescence, BI, and diet.Data Extraction: Data screening, extraction, and quality assessment were performed independently by 2 investigators using the PRISMA and AXIS guidelines.Data Analysis: Of 2496 articles screened, 30 articles, published in English or Spanish, that evaluated the relationship between BI and DHs in adolescents aged between 10 years and 18 years, were included. A relationship between accurate BI perception in adolescents and healthy DHs was reported in 5 articles (16.2%). A relationship between overestimation of body weight in adolescents and healthy DHs was reported in 4 articles (13.3%). A relationship between underestimation of body weight and unhealthy DHs was reported in 8 articles (26.7%). In addition, 4 articles (13.3%) reported a relationship between BIS and healthy DHs. The desire to gain weight was associated with unhealthy DHs in 3 (10%) of the articles, while the desire to lose weight was related to healthy DHs in 3 (10%) of the articles and to unhealthy DHs in 3 (10%) other articles. There were also gender differences in the relationship between BIP or BIS and DHs.Conclusion: Adolescents who underestimate their body weight tend to report less healthy DHs than body weight overestimators. Adolescents unsatisfied with their BI and with a drive for thinness frequently engage in DHs linked to losing weight.Systematic Review Registration: PROSPERO registration no. CRD42020184625.

Unhealthy habits in adolescents are increasing at an alarming rate. The school offers a promising environment in which to implement effective preventive strategies to improve adolescents' lifestyle behaviors. The SI! Program is a multilevel multicomponent school-based health-promotion intervention aimed at all stages of compulsory education in Spain. We present the study design of the SI! Program for Secondary Schools, targeting adolescents aged 12 to 16 years. The main goal of this study is to evaluate the impact of the SI! Program educational intervention on adolescent lifestyle behaviors and health parameters. The study was designed as a cluster-randomized controlled intervention trial and enrolled 1326 adolescents from 24 public secondary schools in Spain, together with their parents/caregivers. Schools and their students were randomly assigned to the intervention group (the SI! curriculum-based educational program over 2 or 4 academic years) or to the control group (usual curriculum). The primary endpoint will be the change from baseline at 2-year and 4-year follow-up in the composite Ideal Cardiovascular Health (ICH) score, consisting of four health behaviors (body mass index, dietary habits, physical activity, and smoking) and three health factors (blood pressure, total cholesterol, and glucose). Secondary endpoints will include 2-year and 4-year changes from baseline in ICH score subcomponents, the Fuster-BEWAT health scale, adiposity markers (waist circumference and body composition), polyphenol and carotenoid intake, and emotion management. The overarching goal of the SI! Program is to instill healthy behaviors in children and adolescents that can be sustained into adulthood. The SI! Program for Secondary School is a comprehensive health-promotion intervention targeting 12-16-year-old adolescents and their immediate environment. The present study addresses the optimal timing and impact of the educational intervention on health in adolescence.

Unhealthy habits in children are increasing at an alarming rate. The school provides a promising setting for effective preventive strategies to improve children's lifestyle behaviors. The SI! Program is a multilevel multicomponent school-based educational intervention aimed at all stages of compulsory education in Spain. Here, we present the design of the SI! Program for Elementary School cluster-randomized controlled trial, targeting children aged 6 to 11 years. This trial aims to study the impact of different timings and intensities of exposure to SI! Program activities on elementary school children and their immediate environment (parents/caregivers, teachers, and school). The trial includes 1770 children from 48 public elementary schools in Madrid (Spain), together with their parents and teachers. Schools and their children were randomly assigned to the intervention group (the SI! curriculum-based educational program over 3 or 6 academic years) or to the control group (standard curriculum). The primary outcomes are the change from baseline at 3-year and 6-year follow-up in children's scores for knowledge, attitudes, and habits (KAH) and health factors (blood pressure, height, weight, waist circumference, and skinfold thickness). Secondary outcomes include 3-year and 6-year changes from baseline in lifestyle questionnaire scores for parents/caregivers and teachers, and in the school environment questionnaire. The overarching goal of the SI! Program is to provide an effective and sustainable health promotion program for the adoption of healthy behaviors in children. The present trial will address the impact and the optimal timing and duration of this educational intervention in the elementary school setting.

This study aimed to develop and validate a liquid chromatography/electrospray ionization-linear ion trap quadrupole-Orbitrap-high-resolution mass spectrometry (HPLC/ESI-LTQ-Orbitrap-HRMS) method to identify and quantify urinary microbial phenolic metabolites (MPM), as well as to explore the relationship between MPM and dietary (poly)phenols in Spanish adolescents. A total of 601 spot urine samples of adolescents aged 12.02 ± 0.41 years were analyzed. The quantitative method was validated for linearity, limit of detection, limit of quantification, recovery, intra- and inter-day accuracy and precision, as well as postpreparative stability according to the criteria established by the Association of Official Agricultural Chemists International. A total of 17 aglycones and 37 phase II MPM were identified and quantified in 601 spot urine samples. Phenolic acids were the most abundant urinary MPM, whereas stilbenes, hydroxytyrosol, and enterodiol were the least abundant. Urinary hydroxycoumarin acids (urolithins) were positively correlated with flavonoid and total (poly)phenol intake. An HPLC-ESI-LTQ-Orbitrap-HRMS method was developed and fully validated to quantify MPM. The new method was performed accurately and is suitable for MPM quantification in large epidemiological studies. Urinary lignans and urolithins are proposed as potential biomarkers of grain and nut intake in an adolescent population.