Educational Nutritional Intervention Program for Adolescents Based on Social Cognitive Theory: Pilot Study of a Cluster Randomized Controlled Trial.

The eating habits of adolescents are often inadequate, with high consumption of unhealthy foods and low consumption of healthy foods. It is necessary to design and implement effective interventions to improve eating habits at this age and evaluate their feasibility, acceptability, and effectiveness. The use of theories for behavior change in health interventions favors the adoption of healthy behaviors. Due to this, the objective was set to determine the feasibility, acceptability, and effect on food consumption of a new educational nutritional intervention program for adolescents based on the Social Cognitive Theory (SCT) and supported by the Trans-theoretical Model (TTM) and identify areas of improvement in study design and intervention for future larger-scale studies. A pilot study of a cluster randomized controlled trial was conducted in adolescents of both sexes, 12 to 15 years of age, students from a public secondary school in Tonala, Jalisco, Mexico. The results show that a nutritional education intervention for adolescents, based on SCT and supported by the TTM, is feasible, acceptable, and with positive results in the modification of the consumption of ultra-processed foods, vegetables/fruits, and water. This pilot study identified some aspects that could be improved to enhance the effectiveness of the interventions in future studies.

A systematic review of educational nutrition interventions based on behavioral theories in school adolescents.

The purpose of this study was to summarize the evidence from studies conducted on adolescents, evaluating educational nutrition interventions for the modification of food consumption through controlled trials based on behavior change theories or models and implemented in school settings. A systematic search was carried out through PubMed and ERIC databases between November and December 2020, and updated in February 2023; English-language keywords were used, and no publication date limits were applied. Two authors independently performed the search, data extraction, data synthesis and risk of bias assessment. Twelve studies meeting the inclusion criteria were included. The interventions were based on different theories; the most used was the Social Cognitive Theory. Eleven of the twelve studies showed favorable modifications in the consumption of at least two of the food groups. Most studies were at low risk of bias, and only one was classified as high risk. It is concluded that educational nutrition interventions based on behavior change theories/models and implemented in the school setting influence positive changes in adolescents eating behavior.

Effect of flaxseed (Linum usitatissimum) supplementation on glycemic control and insulin resistance in prediabetes and type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Prediabetes and type 2 Diabetes Mellitus (T2DM) are characterized by increased blood sugar concentration and insulin resistance. Although there are only a few reports of potential benefits of flaxseed's consumption on different metabolic parameters, there is no evidence of its effect among people with these conditions. OBJECTIVES: The present systematic review and meta-analysis aimed to assess the effect of flaxseed supplementation on glycemic control variables and insulin resistance in prediabetes and T2DM. METHODS: A literature search was conducted through PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science, to identify Randomized Control Trials (RCTs) that evaluated the effect of milled or ground flaxseed supplementation on fasting blood glucose, HbA1c, insulin concentrations, or HOMA-IR. The data were analyzed using Comprehensive Meta-Analysis (CMA) software version 3.3 in a fixed-effect model. RESULTS: Seven studies were included in the systematic review and the meta-analysis, the results showed a significant reduction on fasting blood sugar (SMD: -0.392, 95% CI: -0.596, -0.187, p = <0.001, I2 = 64.81%) insulin concentrations, (SMD: -0.287, 95% CI: -0.534, -0.041, p = 0.022, I2 = 32.53%), HbA1c (SMD: -0.442, 95% CI: -0.770, -0.114, p = 0.008, I2 = 11.058%), and HOMA-IR (SMD: -0.284, 95% CI: -0.530, -0.038, p = 0.024, I2 = 0.00%) after flaxseed supplementation. CONCLUSIONS: Flaxseed supplementation seems to improve glycemic control variables and insulin resistance in prediabetes and T2DM; however, more RCTs are needed to have more decisive evidence about doses, method of supplementation, and the possible effect of synergy with the dietetic treatment.

The Reproducibility and Relative Validity of a Food Frequency Questionnaire for Identifying Iron-Related Dietary Patterns in Pregnant Women.

Analyzing pregnant women's iron intake using dietary patterns would provide information that considers dietary relationships with other nutrients and their sources. The objective of this study was to evaluate the reproducibility and relative validity of a Qualitative Food Frequency Questionnaire to identify iron-related dietary patterns (FeP-FFQ) among Mexican pregnant women. A convenience sample of pregnant women (n = 110) completed two FeP-FFQ (FeP-FFQ1 and FeP-FFQ2) and a 3-day diet record (3DDR). Foods appearing in the 3DDR were classified into the same food groupings as the FeP-FFQ, and most consumed foods were identified. Exploratory factor analysis was used to determine dietary patterns. Scores were compared (FeP-FFQ for reproducibility and FeP-FFQ1 vs. 3DDR for validity) through intraclass correlation coefficients (ICC), cross-classification, Bland−Altman analysis, and weighed Cohen kappa (κw), using dietary patterns scores tertiles. Two dietary patterns were identified: "healthy" and "processed foods and dairy". ICCs (p < 0.01) for "healthy" pattern and "processed foods and dairy" pattern were 0.76 for and 0.71 for reproducibility, and 0.36 and 0.37 for validity, respectively. Cross-classification and Bland−Altman analysis showed good agreement for reproducibility and validity; κw values showed moderate agreement for reproducibility and low agreement for validity. In conclusion, the FeP-FFQ showed good indicators of reproducibility and validity to identify dietary patterns related to iron intake among pregnant women.

Eating control and eating behavior modification to reduce abdominal obesity: a 12-month randomized controlled trial.

BACKGROUND/OBJECTIVES: Abdominal obesity is associated with metabolic disorders, and, in recent years, its prevalence in Korea has continuously increased. The change of lifestyle, particularly diet, is critical for the reduction of abdominal obesity. This study evaluated the effectiveness of an intervention focused on dietary self-efficacy and behaviors on the improvement of abdominal obesity. SUBJECTS/METHODS: Abdominally obese adults with additional cardiovascular risk factors were recruited through 16 medical facilities in South Korea from the year 2013 to 2014. The participants were randomly divided into 2 groups: an intensive intervention group (IG) that received a multi-component intervention to reduce abdominal obesity, by mainly focusing on dietary attitude and dietary behavior change, and a minimal information intervention group (MG) that received a brief explanation of health status and a simple recommendation for a lifestyle change. The interventions were provided for 6 mon, and health examinations were conducted at baseline, 3-, 6-, and 12-mon follow-ups. A path analysis was conducted to identify the process governing the changes in abdominal obesity. RESULTS: The IG showed an improvement in self-efficacy for eating control and diet quality at 6-mon follow-up. Abdominal obesity improved in both groups. Waist circumference was observed to be decreased through the path of "improved self-efficacy for eating control in food availability-eating restriction-improved dietary quality" in IG. Most changes in follow-ups were not significantly different between two groups. CONCLUSIONS: The intensive program targeting the modification of dietary behavior influenced management of abdominal obesity, and the effect occurred through a step-by-step process of change in attitude and behavior. Generally, improvements were also seen in the MG, which supports the necessity of regular health check-ups and brief consultation. The results can be used for further development and implementation of more successful interventions. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0000762.

eHealth Interventions for Fruit and Vegetable Intake: A Meta-Analysis of Effectiveness.

Background. An adequate intake of fruits and vegetables (FVI) has shown benefits for reduced risk of manifesting chronic diseases. Thus, development of effective interventions to promote FVI is paramount. Aim. To assess the effectiveness of eHealth interventions for FVI targeted to healthy population, in comparison with control groups, and identify the moderators contributing to their effectiveness. Method. A database search was conducted in April 2016 and July 2018 using MEDLINE, PsycINFO, ERIC, Google Scholar, SciELO, and RISS, yielding 19 eligible studies. Risk of bias was assessed using Cochrane's Risk of Bias Tool. Random-effects model was used to calculate effect sizes (ES) by weighted standardized mean differences. Results. This meta-analysis includes 19 studies and 6,894 participants. The most common eHealth tool used was Internet-based interventions (n = 10). Most of studies were conducted in adults (n = 11), followed by children (n = 4), and adolescents (n = 4). The minimum number of behavior change techniques (BCTs) used was one, and the maximum seven. The overall ES was small (0.26, p < .001), favoring eHealth interventions. The between-studies heterogeneity was large (I2 = 62.77%, p < .001). Subgroup analyses showed that the components with larger ES were tailored interventions (0.27, p < .001), computer-based interventions (0.44, p < .001), and use of ≥7 BCTs (0.42, p < .001). Discussion. All studies showed a positive ES favoring interventions. Large heterogeneity could be explained in part by the number of BCTs and type of eHealth tool used. Nonetheless, more concrete evidence regarding other intervention components effectiveness was limited by small sample size. Conclusion. The use of eHealth tools for the improvement of FVI showed to be more effective compared with nonintervention and interventions not using these technologies. Nonetheless, more research is needed to determine the specific combination of intervention components that could translate into larger effectiveness.

Validation of a semi-quantitative food frequency questionnaire to assess food groups and nutrient intake / Validación de un cuestionario semi-cuantitativo de frecuencia de consumo de alimentos para determinar la ingestión de grupos de alimentos y nutrientes

Introduction: Semi-quantitative Food Frequency Questionnaires (FFQs) analyze average food and nutrient intake over extended periods to associate habitual dietary intake with health problems and chronic diseases. A tool of this nature applicable to both women and men is not presently available in Mexico. Objective: To validate a FFQ for adult men and women. Methods: The study was conducted on 97 participants, 61% were women. Two FFQs were administered (with a one-year interval) to measure reproducibility. To assess validity, the second FFQ was compared against dietary record (DR) covering nine days. Statistical analyses included Pearson correlations and Intraclass Correlation Coefficients (ICC). The de-attenuation of the ICC resulting from intraindividual variability was controlled. The validity analysis was complemented by comparing the classification ability of FFQ to that of DR through concordance between intake categories and Bland-Altman plots. Results: Reproducibility: ICC values for food groups ranged 0.42-0.87; the range for energy and nutrients was between 0.34 and 0.82. Validity: ICC values for food groups ranged 0.35-0.84; the range for energy and nutrients was between 0.36 and 0.77. Most subjects (56.776.3%) classified in the same or adjacent quintile for energy and nutrients using both methods. Extreme misclassification was <6.3% for all items. Bland-Altman plots reveal high concordance between FFQ and DR. 
Conclusions: FFQ produced sufficient levels of repro-ducibility and validity to determine average daily intake over one year. These results will enable the analysis of possible associations with chronic diseases and dietary diagnoses in adult populations of men and women (AU)

Introducción: Los cuestionarios semicuantitativos de frecuencia de consumo (CFC) analizan ingestión promedio de alimentos y nutrimentos en períodos extensos para asociar consumo habitual con problemas de salud, como enfermedades crónicas. En México, no existe una herramienta similar, aplicable en mujeres y hombres. Objetivo: Validar un CFC en mujeres y hombres adultos. Métodos: El estudio incluyó 97 participantes (61% mujeres). Dos CFC fueron aplicados (un año entre ambos) para medir reproducibilidad. Para validez, se comparó el segundo CFC con registros dietéticos de nueve días. Los análisis incluyeron correlaciones de Pearson y coeficientes de correlación intraclase (CCI). Se controló desatenuación de CCI provocada por la variabilidad intraindividual. El análisis de validez se complementó con la comparación de la capacidad de clasificación entre CFC y registros dietéticos, mediante concordancia de categorías de consumo y gráficos de Bland y Altman. Resultados: Reproducibilidad: los CCI para grupos de alimentos oscilaron entre 0,42-0,87 y para nutrimentos entre 0,34-0,82. Validez: los CCI para grupos de alimentos variaron entre 0,35-0,84 y para nutrimentos entre 0,360,77. La mayoría de sujetos (56,7-76,3%) clasificaron en el mismo quintil o adyacente por ambos métodos (media 66,1%), para energía y nutrimentos. La mala clasificación extrema para todos los ítems fue <6,3%. El análisis con gráficos de Bland y Altman determinó una buena capacidad de acuerdo del CFC, respecto a registros dietéticos. Conclusiones: El CFC obtuvo reproducibilidad y validez adecuadas para determinar ingestión diaria promedio, en un año. Esto permitirá analizar posibles asociaciones con enfermedades crónicas y diagnósticos dietéticos poblacionales en mujeres y hombres adultos (AU)

Validation of a semi-quantitative food frequency questionnaire to assess food groups and nutrient intake.

INTRODUCTION: Semi-quantitative Food Frequency Questionnaires (FFQs) analyze average food and nutrient intake over extended periods to associate habitual dietary intake with health problems and chronic diseases. A tool of this nature applicable to both women and men is not presently available in Mexico. OBJECTIVE: To validate a FFQ for adult men and women. METHODS: The study was conducted on 97 participants, 61% were women. Two FFQs were administered (with a one-year interval) to measure reproducibility. To assess validity, the second FFQ was compared against dietary record (DR) covering nine days. Statistical analyses included Pearson correlations and Intraclass Correlation Coefficients (ICC). The de-attenuation of the ICC resulting from intraindividual variability was controlled. The validity analysis was complemented by comparing the classification ability of FFQ to that of DR through concordance between intake categories and Bland-Altman plots. RESULTS: Reproducibility: ICC values for food groups ranged 0.42-0.87; the range for energy and nutrients was between 0.34 and 0.82. VALIDITY: ICC values for food groups ranged 0.35-0.84; the range for energy and nutrients was between 0.36 and 0.77. Most subjects (56.7-76.3%) classified in the same or adjacent quintile for energy and nutrients using both methods. Extreme misclassification was <6.3% for all items. Bland-Altman plots reveal high concordance between FFQ and DR. CONCLUSIONS: FFQ produced sufficient levels of reproducibility and validity to determine average daily intake over one year. These results will enable the analysis of possible associations with chronic diseases and dietary diagnoses in adult populations of men and women.

Introducción. Los cuestionarios semicuantitativos de frecuencia de consumo (CFC) analizan ingestión promedio de alimentos y nutrimentos en períodos extensos para asociar consumo habitual con problemas de salud, como enfermedades crónicas. En México, no existe una herramienta similar, aplicable en mujeres y hombres. Objetivo. Validar un CFC en mujeres y hombres adultos. Métodos. El estudio incluyó 97 participantes (61% mujeres). Dos CFC fueron aplicados (un año entre ambos) para medir reproducibilidad. Para validez, se comparó el segundo CFC con registros dietéticos de nueve días. Los análisis incluyeron correlaciones de Pearson y coeficientes de correlación intraclase (CCI). Se controló desatenuación de CCI provocada por la variabilidad intraindividual. El análisis de validez se complementó con la comparación de la capacidad de clasificación entre CFC y registros dietéticos, mediante concordancia de categorías de consumo y gráficos de Bland y Altman. Resultados. Reproducibilidad: los CCI para grupos de alimentos oscilaron entre 0.42-0.87 y para nutrimentos entre 0.34-0.82. Validez: los CCI para grupos de alimentos variaron entre 0.35-0.84 y para nutrimentos entre 0.36-0.77. La mayoría de sujetos (56.7-76.3%) clasificaron en el mismo quintil o adyacente por ambos métodos (media 66.1%), para nutrimentos. La mala clasificación extrema para todos los ítems fue.