Behavioral and metabolic characterisation of night eating sydrome

Le syndrome de fringale nocturne (SFN) est caractérisé par un retard de l'apport énergétique et se manifeste soit comme une hyperphagie en soirée et/ou des ingestions nocturnes. D’autres caractéristiques cliniques de ce syndrome ont été identifiées : anorexie du matin, l'insomnie, un désire intense de manger le soir, une humeur dépressive et/ou une humeur qui se détériore en soirée, et la conviction que la personne doit manger pour dormir. Bien que la recherche sur NES a progressé de façon constante depuis l’apparition de ce syndrome dans la littérature scientifique en 1955, plusieurs questions n’ont pas été étudiées. En effet, une seule étude a examiné les symptômes du SFN chez les enfants et aucune n’a examiné les comportements de santé associés aux symptômes. De plus, bien que deux études aient démontré que les ingestions alimentaires nocturnes prédisent une plus grande prise de poids, il n’est pas clair si le poids ou certains marqueurs de la santé métabolique ont été associée à d'autres symptômes du syndrome. Enfin, aucune étude n’a exploré le changement des symptômes au fil du temps. Ainsi, l'objectif de cette étude était de mieux caractériser les comportements de santé et le profil métabolique associés à des symptômes du SFN dans une cohorte familiale. Un objectif secondaire visait à valider certains aspects du questionnaire qui mesure les symptômes du SFN de façon auto-déclarées, le « night eating questionnaire » (NEQ). L'échantillon de l'étude comprenait des participants de l'étude de cohorte longitudinale de QUALITY (parents biologiques et leur enfant âgé de 8 - 10 ans) évalués à deux reprises : entre 2005 - 2008 et 2008 – 2010. Dans l'ensemble, cette thèse montre que peu de personnes répondent aux critères du SFN, que ces symptômes sont liés à un délai dans certains comportements de santé (activité physique et nutrition) chez les enfants et que certains symptômes sont reliés au profil métabolique et à un gain de poids chez les parents.Night eating syndrome (NES) is characterised by a delayed pattern of energy intake and manifests as either evening hyperphagia and/or nocturnal ingestions of food. Other clinical features of this syndrome have been identified and include morning anorexia, insomnia, strong evening cravings for food, a depressed and/or evening-worsening mood and a belief that one must eat in order to sleep. Research on NES has progressed steadily since the disorder first appeared in the scientific literature in 1955. However, there is much more to be learned on the topic of NES. There is only one published study that examined night eating symptoms in children. There are no published studies that have examined health behaviours associated with these symptoms in children and none that have examined changes in NES symptoms across time. Furthermore, although two studies have demonstrated that nocturnal ingestions of food predicted greater weight gain, they did not explore if weight gain or markers of metabolic health were associated with other NES symptoms. Thus, the objective of this study was to examine the behavioural and metabolic characterisation of night eating symptoms in a family cohort. Furthermore, a secondary objective was to validate certain aspects of the Night Eating Questionnaire (NEQ), a measure of self-reported NES symptoms. The study sample consisted of participants of the longitudinal QUALITY cohort study and included two biological parents and one child aged 8 – 10 years upon recruitment and data were collected at two time points, from 2005 - 2008 and from 2008 – 2010. This thesis demonstrates that few individuals meet criteria for NES.NES symptoms are related to a behavioural delay in children and may be associated with a less healthful diet. Furthermore, certain night eating symptoms are related to weight gain and metabolic health in adults

Characteristics of individuals who report present and past weight loss behaviours: results from a Canadian university community

Purpose: To characterise individuals who reported present and past weight loss behaviours on psycho-behavioural factors known to influence body weight, e.g. overeating, dietary restriction. Methods: An online questionnaire was distributed to a university community. Questions pertaining to present weight loss, previous weight loss, eating behaviour tendencies, perceived stress and sleep quality were answered by 3,069 individuals. Body weight and height were selfreported. Results: Present and past weight loss behaviours were prevalent in the sample, with 33.3 % of the participants who reported trying to lose weight, 33.1 % who reported having previously lost weight ([10 lbs), and 18.8 % who reported repeated weight loss behaviour (i.e. present and past weight loss behaviours). Trying to lose weight and previous weight loss were both independently associated with increased risk for psycho-behavioural characteristics known to be associated with obesity, e.g. overeating tendencies, perceived stress, short sleep duration. This risk was particularly elevated among the underweight/normalweight individuals who reported repeated weight loss behaviours. Indeed, adjusted odds ratios for reporting restrictive and overeating tendencies, perceived stress and short sleep for these individuals were significantly higher compared to their underweight/normal-weight peers who did not report repeated weight loss behaviours (adjusted odds ratios 4.7, 2.7, 1.8, and 1.8, respectively, p\0.01 to \0.0001). Conclusions: Normal-weight individuals reporting weight loss behaviours are characterised by a psycho-behaviour profile which may further increase their risk of weight gain

Past dieting is related to rigid control and disinhibition in adolescents from the Québec Family Study

Eating behaviour traits of rigid control and disinhibition have been associated with body weight in both adults and adolescents. Moreover, adults reporting a dieting history have increased levels of unhealthy eating behaviours. Against this background, the present study aimed to examine the relationship between dieting history and eating behaviour traits in adolescents. For the purpose of this research, a total of sixty adolescents (aged 15 (sem 2·4) years) from the Québec Family Study completed the Three-Factor Eating Questionnaire (TFEQ) and a questionnaire regarding eating habits. Self-reported current and past dieting were analysed against eating behaviour traits measured by the TFEQ, including all subscales. As the results revealed, few adolescents reported currently dieting (n 3). Adolescents who reported a dieting history (23·3 %) were older (16·9 v. 14·4 years, P < 0·001), were more likely to be female (78·6 v. 41·3 %, P < 0·05) but did not have a significantly higher BMI z-score (1·5 v. 0·9, P = 0·10), although they were more likely to be either overweight or obese (P < 0·01). After correcting for sex, BMI and age, adolescents who reported a dieting history had higher levels of rigid control and disinhibition (P < 0·05–0·0001) than those reporting no dieting history. A greater proportion of adolescents characterised by high rigid control and high disinhibition were past dieters, compared to those characterised by low levels of both behaviour traits (53 v. 4 %). The study arrived at the following conclusions: as observed in adults, adolescents with a history of dieting present unfavourable eating behaviour traits. These behavioural traits may represent an additional challenge to the long-term regulation of body weight

Régulation de la prise alimentaire consécutive à un travail mental exigeant

Knowledge-based work has been identified as a potential factor that might accentuate positive energy balance and weight gain. The reasons explaining this relationship and the gender differences previously observed are still unknown. To investigate the relationships between mental effort, cognitive restraint and motivation based on the Strength Model of Self-Regulation, in order to predict eating regulation following a demanding mental work. The protocol consists of a randomized crossover design including 3 conditions (knowledge-based work, exercise and control) followed by an ad libitum buffet measuring eating regulation. Mental effort is measured by the average reaction time (RT) to a second mental task. Questionnaires were administrated at baseline to evaluate global motivation and eating behaviour traits. Cognitive restraint, motivation and mental effort variables do not significantly moderate the relationship between experimental conditions and eating regulation. Controlled form of motivation is significantly correlated with flexible restraint, r = .3, p = .04, rigid restraint, r = .4, p = .03 and disinhibition, r = .3, p = .047. Controlled motivational variable is associated to behaviour traits likely to impair adequate eating regulation, but these associations do not seem to moderate acute food intake regulation following knowledge-based work. Knowledge-based work and flexible cognitive restraint independently increase mental effort, having the potential to weaken self-regulation.Le travail mental exigeant (TME) figure parmi les déterminants émergents ayant le potentiel d’influencer la prise alimentaire et le poids. Les facteurs explicatifs et les différences de genre observées précédemment sont toutefois méconnus. Examiner la validité du modèle de l’autorégulation pour prédire la régulation de la prise alimentaire consécutive à un TME, et ce, en évaluant la relation entre l’effort cognitif, la restriction cognitive et la motivation. Le devis de l’étude est un chassé-croisé aléatoire incluant trois conditions (TME, Activité physique, Repos), suivies d’un buffet servi à volonté. L’effort cognitif est mesuré en déterminant le temps de réaction à une deuxième tâche. La restriction cognitive et la motivation globale sont évaluées au moyen de questionnaires. La relation entre les trois conditions et la régulation de la prise alimentaire n’est pas influencée de façon significative par la restriction cognitive, la motivation ou l’effort cognitif (temps de réaction). Toutefois, la relation entre les conditions expérimentales et l’effort cognitif est influencée significativement par la restriction flexible (p = 0,005). La motivation contrôlée est significativement associée à la restriction flexible, r = 0,3, p = 0,04, la restriction rigide, r = 0,4, p = 0,03, et la désinhibition alimentaire, r = 0,3, p = 0,047. Malgré les associations observées entre la motivation contrôlée et certaines caractéristiques susceptibles de nuire à la régulation de la prise alimentaire, aucune d’entre elles ne semble expliquer directement la régulation de la prise alimentaire consécutive à un TME. Le TME et la restriction cognitive flexible augmentent tous deux l’effort cognitif de façon indépendante et ont le potentiel de diminuer l’autorégulation

Immunoaffinity chromatography: an introduction to applications and recent developments

Immunoaffinity chromatography (IAC) combines the use of LC with the specific binding of antibodies or related agents. The resulting method can be used in assays for a particular target or for purification and concentration of analytes prior to further examination by another technique. This review discusses the history and principles of IAC and the various formats that can be used with this method. An overview is given of the general properties of antibodies and of antibodyproduction methods. The supports and immobilization methods used with antibodies in IAC and the selection of application and elution conditions for IAC are also discussed. Several applications of IAC are considered, including its use in purification, immunodepletion, direct sample analysis, chromatographic immunoassays and combined analysis methods. Recent developments include the use of IAC with CE or MS, ultrafast immunoextraction methods and the use of immunoaffinity columns in microanalytical systems

Eating behaviours and body weight in adolescents

La plus grande augmentation de la prévalence d'obésité au Canada se retrouve parmi les adolescents. L'obésité chez les jeunes est associée à des problèmes de santé pendant l'adolescence et, parce qu'elle augmente fortement les chances d'être obèse à l'âge adulte, elle est aussi associée à des problèmes de santé plus tard dans la vie. Il y a plusieurs facteurs responsables de cette épidémie d'obésité. Les comportements alimentaires sont un aspect associé avec le poids chez les adultes, et moins connus, chez les jeunes. Le Three-Factor Eating Questionnaire, qui mesure le niveau de restriction, désinhibition et la susceptibilité à la faim, est le questionnaire le plus utilisé en recherche pour évaluer les comportements alimentaires. Toutefois, ce questionnaire n'a pas été beaucoup utilisé chez les adolescents et il n'y a aucune étude qui a mesuré les sous-échelles de comportements alimentaires chez cette population. Cette étude avait comme objectif d'identifier les comportements alimentaires associés au poids corporel chez un groupe d'adolescents faisant partie de l'Étude des familles de Québec. Le contrôle rigide, la désinhibition et la susceptibilité aux émotions étaient positivement associés à l'indice de masse corporelle (IMC; p < 0.05). L'association entre l'IMC et le contrôle rigide était plus forte pour les filles tandis que l'association entre l'IMC et la désinhibition était plus forte chez les garçons. Pour comparer l'interaction entre les comportements alimentaires et le poids corporel, les adolescents ont été classifies en catégories selon leur niveau de contrôle rigide et leur désinhibition. Les adolescents qui présentaient les plus hauts scores pour ces deux comportements avaient un IMC plus élevé (p < 0.05). La restriction flexible n'était pas associée à l'IMC chez ce groupe d'adolescents. La susceptibilité à la faim était le seul comportement alimentaire qui était relié à l'apport calorique. Les adolescents avec un surplus de poids présentaient des niveaux de désinhibition et de contrôle rigide plus élevés que les adolescents de poids normal. Ces résultats démontrent l'importance d'évaluer ces comportements alimentaires chez les jeunes afin de développer des stratégies d'intervention efficace dans le traitement et la prévention de l'obésité

Homeostatic and circadian control of food intake : clinical strategies to prevent overconsumption.

The current environment has a strong impact on the rise in population body weight as it provides ample opportunity to consume food, often beyond one’s metabolic requirement. The homeostatic processes that regulate food intake are often overlooked or weakened in such an environment, particularly among susceptible individuals. Moreover, there is strong circadian control over food intake and the circadian system is tightly entwined in body weight regulation. Clinical nutritional and behavioral strategies can strengthen homeostatic signals of satiation and satiety and improve appetite control. Synchronizing the circadian system through exercise and regular sleeping and meal patterns may also enhance these signals. Together, these strategies can help reduce overeating episodes, particularly among susceptible individuals, and may play a role in better long-term body weight regulation

The night eating syndrome and obesity

The rising prevalence of obesity is a global concern. Eating behaviour and circadian rhythm are proving to be important factors in the aetiology of obesity. The night-eating syndrome (NES) is characterized by increased late-night eating, insomnia, a depressed mood and distress. It is evident that prevalence is higher among weight-related populations than the general community. The exact relationship between this syndrome and obesity remains unclear. The reasons for the discrepancies found in the literature likely include varying diagnostic criteria and a wide range of study population characteristics. NES does not always lead to weight gain in thus certain individuals may be susceptible to night-eating-related weight gain. Weight loss through surgical and behavioural treatments has shown success in diminishing symptoms. The increasing literature associating obesity with circadian imbalances strengthens the link between the NES and obesity. Circadian genes may play a role in this syndrome. This review will examine different aspects of obesity in the context of the NES

Nutritional aspects of late eating and night eating

The timing of food intake has been investigated as a novel factor in the etiology, maintenance, and treatment of obesity. Indeed, consuming a large proportion of food later in the day and into the night has been associated with higher body weight and may even impair weight loss. The diet quality of late-eaters may be a factor involved in these relationships. Moreover, the nutritional characteristics of the foods consumed during the night may negatively affect metabolic and circadian rhythms that are required for optimal health. This review will first examine the diet quality of late-eaters and describe common foods consumed as nocturnal snacks. Second, this review will briefly acknowledge the potential adverse metabolic and circadian effects of consuming certain foods very late in the evening or during the night

The effectiveness of a school-based nutrition intervention on children’s fruit, vegetables, and dairy product intake

BACKGROUND : Most Canadian children do not meet daily recommendations for consumption of vegetables and fruits (V/F) and dairy products (DP). The aim of this study was to evaluate the impact of Team Nutriathlon on V/F and DP consumption of children. METHODS : Participants were 404 children from grades 5 and 6 (intervention group [IG] N = 242, control group [CG] N = 162). Teams of children were guided to increase their consumption and variety of V/F and DP over an 8-week period. Daily servings of V/F and DP were compared between groups at 4 time points: baseline (week 0), during (week 6), immediately after (week 9 or 10), and a follow-up 10 weeks after (week 20) the intervention. RESULTS : During and after the program and at follow-up, children in the IG consumed more servings of V/F and DP compared to the CG (group × time, p .05). CONCLUSIONS : Team Nutriathlon is an innovative school-based nutrition program that can help to increase the V/F and DP consumption of children