Évaluation d'une intervention visant la promotion de comportements alimentaires favorables à une saine gestion du poids chez les jeunes athlètes féminines

Ce mémoire présente, premièrement, une étude qui avait pour but d’évaluer les connaissances en nutrition et leur association avec la qualité de l’alimentation d’athlètes féminines de niveau secondaire. Les résultats démontrent que les adolescentes athlètes semblent avoir de meilleures connaissances en nutrition que les adolescentes non-athlètes. Cependant, un meilleur niveau de connaissance ne se traduit pas par une meilleure qualité de l’alimentation. Deuxièmement, un article concernant l’évaluation d’une intervention basée sur la théorie du comportement planifié (TCP) et visant à diminuer l’intention d’utiliser des méthodes alimentaires restrictives chez les adolescentes athlètes pratiquant des sports à dominance esthétique est présenté. Les résultats démontrent que l’ajout de composantes issues de la TCP à une intervention visant à augmenter les connaissances en nutrition semble avoir un effet favorable à court terme pour diminuer l’intention d'utiliser des comportements alimentaires restrictifs chez cette population

Validation of a newly automated web-based 24-hour dietary recall using fully controlled feeding studies

BACKGROUND: Assessment of food intake is a cornerstone of nutritional research. However, the use of minimally validated dietary assessment methods is common and can generate misleading results. Thus, there is a need for valid, precise and cost-effective dietary assessment tools to be used in large cohort studies. The objective is to validate a newly developed automated self-administered web-based 24-h dietary recall (R24W), within a population of adults taking part in fully controlled feeding studies. METHODS: Sixty two adults completed the R24W twice while being fed by our research team. Actual intakes were precisely known, thereby allowing the analysis of the proportion of adequately self-reported items. Association between offered and reported portion sizes was assessed with correlation coefficients and agreement with the kappa score while systematics biases were illustrated with Bland-Altman Plot. RESULTS: Participants received an average of 16 food items per testing day. They reported 89.3% of the items they received. The more frequently omitted food categories were vegetables included in recipes (40.0%) as well as side vegetables (20.0%) and represented less than 5% of the actual daily energy intake. Offered and self-reported portion sizes were significantly correlated (r = 0.80 P < 0.001) and demonstrated a strong agreement as assessed by the kappa score of 0.62. Reported portion sizes for individual food items were on average 3.2 g over the offered portion sizes. Portions of 100 g and above were on average underestimated by 2.4% (r = 0.68 P < 0.01; kappa score = 0.50) while small portions (less than 100 g) were overestimated by 17.1% (r = 0.46 P < 0.01; kappa score = 0.43). A nonsignificant underestimation (−13.9 kcal ± 646.3 kcal; P = 0.83) of energy intake was noted. CONCLUSION: R24W performed well as participants were able to report the great majority of items they ate and selected portion size strongly related to the one they received. This suggests that food items are easily to find within the R24W and images of portion sizes used in this dietary assessment tool are adequate and can provide valid food intake evaluation

Validation of a french-canadian adaptation of the intuitive eating scale-2 for the adult population

Intuitive eating is an adaptive eating style based on the reliance on physiological cues to determine when, what, and how much to eat. The Intuitive Eating Scale-2 (IES-2) is a validated four-subscale tool measuring the degree of adherence to intuitive eating principles. The present series of studies aimed at evaluating the psychometric properties of a French-Canadian adaptation of the IES-2 for the adult population. The factor structure, the reliability (internal consistency and test-retest), the construct validity, and the discriminant validity were evaluated in 334 women and 75 men from the Province of Québec, Canada, across two studies. A confirmatory factor analysis upheld that the four-factor structure of the original IES-2 was adequate for the present sample of French-Canadians. The scale demonstrated adequate internal consistency and test-retest reliability. Construct validity evidence was obtained with the significant associations between intuitive eating and psychological and eating-related variables. Intuitive eating was negatively associated with eating disorder symptomatology and with food- and weight-preoccupation, and positively associated with body-esteem and well-being. The French-Canadian IES-2 was also able to discriminate between genders and body mass index categories. The properties of this new version of the IES-2 are demonstrative of a reliable and valid tool to assess intuitive eating in the French-Canadian adult population of the Province of Québec

Evaluation of a theory-based intervention aimed at reducing intention to use restrictive dietary behaviors among adolescent female athletes

Objective: To evaluate the effectiveness of a theory-based intervention to reduce the intention to use restrictive dietary behaviors for losing weight among adolescent female athletes involved in aesthetic sports. Design: Cluster randomized controlled trial. Setting: Aesthetic sport teams of adolescent (age 12-17) female athletes. Participants: Two teams (n=37 athletes) in the intervention group and 3 teams (n=33) in the comparison group. Interventions: The 2 groups received nutrition education during 3 weekly 60-min sessions. The intervention group was further exposed to a theory-based intervention targeting the specific determinant of intention to use restrictive dietary behaviors for losing weight, namely attitude. Main Outcome Measures: Difference over time between groups in intention to use restrictive dietary behaviors for losing weight and in nutrition knowledge. Analysis: Mixed models for repeated measures. Results: The theory-based intervention contributed to maintaining a low intention of using restrictive dietary behaviors for losing weight over time in the intervention group compared to the comparison group. Nutrition knowledge score increased equally in both groups. Conclusion and implications: Complementing nutrition education with theory-based behavior change intervention may help maintain a low intention of using restrictive dietary behaviors for losing weight among high-school female athletes involved in aesthetic sport

Determinants of restrictive dietary behaviors among female high school athletes

This study assessed the determinants of intention to adopt restrictive dietary behaviors to lose weight among high school female athletes. Methods: Female athletes (N = 255) and non-athlete controls (N = 91) completed a questionnaire based on the theory of planned behavior. Results: Intention to adopt restrictive dietary behaviors to lose weight, which had a prevalence of 22%-29% among athletes and controls, was correlated primarily with attitude towards this behavior (R2 = 45%, p < .0001). Attitude was in turn correlated with improvement in appearance (R2 = 37%, p < .0001). Conclusions: Improvement in appearance is a key belief to address in interventions aimed at decreasing the intention to use restrictive dietary behaviors to lose weight among adolescent female athletes

Intakes of total, free, and naturally occurring sugars in the french-speaking adult population of the province of Québec, Canada : the PREDISE study

The objective of this study was to characterize the intakes of different types of sugars in an age- and sex-representative sample of French-speaking adults from five regions of the Province of Québec, Canada, enrolled in the cross-sectional PREDISE (PRÉDicteurs Individuels, Sociaux et Environnementaux) study (n = 1147, 18–65 years old; 50.2% women). Because only total sugar content of foods and beverages is available in the Canadian Nutrient File (CNF) 2015, the initial step of this study was thus to build a database of free and naturally occurring sugars content of each food item and recipe included in the R24W, which is an automated, self-administered, web-based, 24-h dietary recall validated to estimate nutrient intakes in French-speaking adults of the Province of Québec. Total sugars were manually differentiated into free and naturally occurring sugars using a systematic algorithm based on previously published systematic algorithms. The World Health Organization (WHO)’s free sugar definition was used to differentiate total sugars into free and naturally occurring sugars. Dietary intake estimates were assessed using three 24-h dietary recalls completed with the R24W. Mean total, free, and naturally occurring sugar intakes were 116.4 g (19.3% of daily energy intake (%E)), 72.5 g (11.7%E), and 44.0 g (7.5%E), respectively. Over half (57.3%) of the overall sample did not meet the WHO’s recommendation to consume less than 10%E from free sugars. Women had a higher %E from naturally occurring sugars than men and being younger was associated with a greater %E from free sugars. Sugar intakes among French-speaking adults from the Province of Québec were mainly in the form of free sugars, with the majority of the population exceeding the WHO recommendation regarding free sugar intake. This suggests that public health efforts towards reducing free sugar intake in this population are relevant and necessary, considering that overconsumption of free sugars negatively influences health outcomes

Strange Attractors

Catalog for the exhibition Strange Attractors held at the Seton Hall University Walsh Gallery, January 16 - March 8, 2019. Curated by Taney Roniger and Jeanne Brasile

Electrospinning of highly crystalline polymers for strongly oriented fibers

Electrospun nanofibers (NFs) often demonstrate an exponential increase in mechanical and other properties at reduced diameters. Molecular orientation emerges as a key parameter for the performance of amorphous and low crystallinity polymers, but single-fiber structural investigations are still lacking for highly crystalline polymers. Herein, polarized confocal Raman spectroscopy reveals that fibers of highly crystalline poly(ethylene oxide) (PEO) maintain a high orientation over a broad range of diameters, in strong contrast with the usual exponential trend. This observation stands for five electrospinning solvents of widely different properties. By comparison, poly(oxymethylene) (POM) NFs also show a high orientation at low diameters, but it decreases substantially for diameters larger than ∼1400 nm, a result attributed to the lower crystallinity of POM compared to that of PEO. The results show that the exponential orientation dependence on fiber diameter is not universal and stress the importance of polymer crystallinity on the structure and properties of electrospun nanofibers. This work guides the preparation of fibers with optimal orientation-dependent properties and shows that high crystallinity can afford more robust materials whose performance is less affected by variations in experimental conditions, a valuable feature for most applications