Gary Goldfield | University of Ottawa | Université d'Ottawa (original) (raw)

Papers by Gary Goldfield

Research paper thumbnail of Effects of weight teasing and gender on body esteem in youth: A longitudinal analysis from the REAL study

Research paper thumbnail of Physical activity and cognition in children and youth: A systematic review

Journal of Exercise, Movement, and Sport (SCAPPS refereed abstracts repository), Oct 21, 2018

Research paper thumbnail of The Research on Eating and Adolescent Lifestyle (REAL) Study Protocol: A Shared Biopsychosocial Model for Predicting Eating Disorders and Obesity in Adolescents

This manuscript describes the rationale, design and methods of the Research on Eating and Adolesc... more This manuscript describes the rationale, design and methods of the Research on Eating and Adolescent Lifestyles Study (REAL), which from 2006-2013, aimed to test an integrative biopsychosocial model of cross-sectional and longitudinal predictors and developmental mechanisms for both eating disorders (EDs) and obesity in a large sample of Canadian youth. The present study examined predictors from four main areas of risk: biological (e.g. weight status, pubertal stage), environmental (e.g. societal influences), individual (e.g. self-perception), and eating and weight specific behaviors (e.g. disordered eating) to test direct and indirect paths for both ED and obesity simultaneously as outcomes. Participants were recruited based on a convenience sample from 43 urban and rural public schools, and data collection ran from 2006-2013. The cross sectional sample consisted of 3043 males and females in grades 7-12. The longitudinal sample was comprised of 1197 students in grades 7 and 9 who completed annual follow ups for 7 years. The REAL study is unique as it proposes a biopsychosocial model to explain EDs and obesity in adolescents under parallel processes within a single model, and is more integrative and comprehensive than previous models. Findings from this study were intended to inform prevention initiatives and further the understanding of the etiological similarities amongst EDs and obesity in a large sample of both male and female youth across adolescence.

Research paper thumbnail of Longitudinal association between movement behaviours and depressive symptoms among adolescents using compositional data analysis

Research paper thumbnail of Evaluating the psychometric properties of the parent-rated Strengths and Difficulties Questionnaire in a nationally representative sample of Canadian children and adolescents aged 6 to 17 years

Health Reports, Aug 19, 2020

Background: The Strengths and Difficulties Questionnaire (SDQ) is a brief measure of children's a... more Background: The Strengths and Difficulties Questionnaire (SDQ) is a brief measure of children's and adolescents' mental health. There are different versions of the questionnaire: a version for children and adolescents to complete by self-reporting, a version for parents and guardians to complete ("parent-rated"), and a version for teachers to complete. The purpose of this study was to examine the psychometric properties of the parent-rated SDQ with a nationally representative sample of Canadian children and adolescents. Data and methods: Data are from cycle 1 (2007 to 2009), cycle 2 (2009 to 2011), cycle 3 (2012 to 2013) and cycle 4 (2014 to 2015) of the Canadian Health Measures Survey. Data include 7,451 Canadian children and adolescents aged 6 to 17 years (49.3% female). Parents and guardians completed the SDQ by reflecting on their child's behaviour over the past six months. Factorial validity was examined via confirmatory factor analysis, which included testing the original five-factor SDQ model and alternative three-factor and higher-order models. Reliability was assessed through composite reliability scores. Measurement invariance across subgroups was also assessed. Results: The original five-factor (i.e., emotional symptoms, conduct problems, peer problems, hyperactivity and prosocial behaviour) SDQ fit the data satisfactorily, demonstrated evidence of reliability, and was invariant across sex (male vs. female), age (children vs. adolescents) and survey language (English vs. French). The higher-order solution fit the data acceptably, and the three-factor solution did not fit the data well. Discussion: The original five-factor, parent-rated SDQ demonstrates evidence of factorial validity and reliability as a population measure of mental health difficulties among Canadian children and adolescents.

Research paper thumbnail of Physical activity and brain structure, brain function, and cognition in children and youth: A systematic review of randomized controlled trials

Mental Health and Physical Activity, Mar 1, 2019

Research paper thumbnail of Systematic review of sedentary behaviour and health indicators in school-aged children and youth

International Journal of Behavioral Nutrition and Physical Activity, 2011

Research paper thumbnail of 24-HOUR Movement Guidelines and Suicidality Among Adolescents

Journal of Affective Disorders, Sep 1, 2020

BACKGROUND The 24-hour movement guidelines for children and youth recommend ≥60 min/day of modera... more BACKGROUND The 24-hour movement guidelines for children and youth recommend ≥60 min/day of moderate-to-vigorous physical activity, ≤2 h/day of screen time, 9-11 h/night of sleep for 11-13 years and 8-10 h/night for 14-17 years. The objectives of this study were to examine the associations between meeting combinations of the recommendations contained within the 24-hour movement guidelines for children and youth and suicidal ideation and suicide attempts, and test whether age and gender moderate these associations. METHODS Data on 10,183 students were obtained from the 2015-2017 Ontario Student Drug Use and Health Survey, a representative cross-sectional survey of Ontario students in grades 7-12 (mean [SD] age, 15.2 [1.8] years). RESULTS Suicidal ideation and suicide attempts were reported by 13.1% and 3.3% of students, respectively. Meeting individual recommendations or combinations of recommendations were differentially associated with suicidal ideation and suicide attempts between adolescent boys and girls and younger and older (three-way interactions statistically significant for both outcomes). Meeting all 3 recommendations was associated with lower odds of suicidal ideation (OR: 0.24, 95% CI: 0.09 - 0.69) and suicide attempts (OR: 0.08, 95% CI: 0.02 - 0.41) among boys aged 15 to 20 years, but not those aged 11 to 14 years nor girls in both age groups. LIMITATIONS The cross-sectional nature of the data precludes causal inferences and there is possibility of bias related to self-reports. CONCLUSIONS These findings suggest that adherence to the 24-hour movement guidelines among adolescents is related to lower odds of suicidality in older boys.

Research paper thumbnail of Electronic Maternal Health Survey

Research paper thumbnail of Effects of interactive video game cycling on overweight and obese adolescent health

Applied Physiology, Nutrition, and Metabolism, Dec 1, 2010

Research paper thumbnail of Screen Viewing and Diabetes Risk Factors in Overweight and Obese Adolescents

American Journal of Preventive Medicine, Apr 1, 2013

Sedentary behavior has been associated with deleterious cardiometabolic health indicators in adul... more Sedentary behavior has been associated with deleterious cardiometabolic health indicators in adults, but very little research has examined this relationship in youth. To examine the association between the duration and type of sedentary screen behavior with diabetes risk factors (fasting glucose, insulin, homeostasis model-insulin resistance [HOMA-IR], 2-hour postload glucose, hemoglobin A1c) in a sample of overweight and obese adolescents. A cross-sectional study of 307 overweight or obese adolescents aged 14-18 years (90 boys, 217 girls) assessed at baseline of a lifestyle intervention for weight control conducted from 2005 to 2010. Sedentary screen behaviors, defined as hours per day spent watching TV, playing seated video games, recreational computer use, and total screen time were measured by self-report. Data were analyzed using linear regression analyses in 2012. TV viewing was the only type of sedentary screen behavior associated with elevated diabetes risk factors before and after adjustment for confounders. Specifically, TV viewing remained positively associated with fasting insulin (adjusted r=0.11, β=0.10, p=0.048) and HOMA-IR (adjusted r=0.11, β=0.10, p=0.05) after adjustment for age, gender, waist-to-hip ratio, caloric intake, percentage of intake in carbohydrates, physical activity duration, and physical activity intensity. TV watching may be independently associated with an increase in diabetes risk factors in a high-risk sample of overweight and obese adolescents. These findings provide support for interventions designed to reduce time spent watching TV as a possible means to attenuating diabetes risk factors in this high-risk population.

Research paper thumbnail of Associations between the Canadian 24 h movement guidelines and different types of bullying involvement among adolescents

Child Abuse & Neglect, Oct 1, 2020

Research paper thumbnail of Combinations of physical activity, sedentary time, and sleep duration and their associations with depressive symptoms and other mental health problems in children and adolescents: a systematic review

International Journal of Behavioral Nutrition and Physical Activity, Jun 5, 2020

Research paper thumbnail of The Canadian 24-Hour Movement Guidelines and Psychological Distress among Adolescents: Les Directives canadiennes en matière de mouvement sur 24 heures et la détresse psychologique chez les adolescents

The Canadian Journal of Psychiatry, Nov 27, 2020

Research paper thumbnail of Brain on Fire: Incentive Salience, Hedonic Hot Spots, Dopamine, Obesity, and Other Hunger Games

Annual Review of Nutrition, Aug 21, 2017

This review examines human feeding behavior in light of psychological motivational theory and hig... more This review examines human feeding behavior in light of psychological motivational theory and highlights the importance of midbrain dopamine (DA). Prospective evidence of both reward surfeit and reward deficit pathways to increased body weight are evaluated, and we argue that it is more complex than an either/or scenario when examining DA's role in reward sensitivity, eating, and obesity. The Taq1A genotype is a common thread that ties the contrasting models of DA reward and obesity; this genotype related to striatal DA is not associated with obesity class per se but may nevertheless confer an increased risk of weight gain. We also critically examine the concept of so-called food addiction, and despite growing evidence, we argue that there is currently insufficient human data to warrant this diagnostic label. The surgical and pharmacological treatments of obesity are discussed, and evidence is presented for the selective use of DA-class drugs in obesity treatment.

Research paper thumbnail of 24-Hour Movement Behaviors and Impulsivity

Pediatrics, Sep 1, 2019

BACKGROUND: The objective of this study was to examine individual and concurrent associations bet... more BACKGROUND: The objective of this study was to examine individual and concurrent associations between meeting the Canadian 24-Hour Movement Guidelines for Children and Youth (9–11 hours of sleep per night, ≤2 hours of recreational screen time (ST) per day, and at least 60 minutes of moderate to vigorous physical activity per day) and dimensions of impulsivity. METHODS: Data from this cross-sectional observational study were part of the first annual curated release of the Adolescent Brain Cognitive Development Study. Participants included 4524 children between the ages of 8 and 11 years. RESULTS: In analyses, it was shown that adherence to individual movement behavior recommendations as well as combinations of adherence to movement behavior recommendations were associated with each dimension of impulsivity. Meeting all 3 movement behavior recommendations was associated with lower positive urgency (95% confidence interval [CI]: −0.12 to −0.05), negative urgency (95% CI: −0.04 to −0.08), Behavioral Inhibition System (95% CI: −0.08 to −0.01), greater perseverance (95% CI: 0.09 to 0.15), and better scores on delay-discounting (95% CI: 0.57 to 0.94). Meeting the ST and sleep recommendations was associated with less impulsive behaviors on all dimensions of impulsivity: negative urgency (95% CI: −0.20 to −0.10), positive urgency (95% CI: −0.16 to −0.08), perseverance (95% CI: 0.06 to 0.15), Behavioral Inhibition System (95% CI: −0.15 to −0.03), Behavioral Activation System (BAS) reward responsiveness (95% CI: −0.04 to −0.05), BAS drive (95% CI: −0.14 to −0.06), BAS fun-seeking (95% CI: −0.15 to −0.17), and delay-discounting task (95% CI: 0.68 to 0.97). CONCLUSIONS: Findings support efforts to determine if limiting recreational ST while promoting adequate sleep enhances the treatment and prevention of impulsivity-related disorders.

Research paper thumbnail of The association between social media use and physical activity among Canadian adolescents: a Health Behaviour in School-aged Children (HBSC) study

Canadian Journal of Public Health-revue Canadienne De Sante Publique, Mar 15, 2023

Research paper thumbnail of Mediating role of disordered eating in the relationship between screen time and BMI in adolescents: longitudinal findings from the Research on Eating and Adolescent Lifestyles (REAL) study

Public Health Nutrition, Aug 13, 2020

Objective:This study investigated whether the duration and type of screen time (ST) (TV viewing, ... more Objective:This study investigated whether the duration and type of screen time (ST) (TV viewing, recreational computer use, video gaming) is longitudinally associated with z-BMI and if these relationships are mediated by disordered eating (emotional, restrained).Design:At baseline, participants were n 1197 (T1; 60 % female) adolescents (mean age = 13·51 years) who completed surveys over 2 years. ST was assessed by a self-reported measure created by the investigative team, while emotional and restrained eating was measured by the Dutch Eating Behaviour Questionnaire (DEB-Q). Height and weight were objectively measured to quantify z-BMI.Setting:Thirty-one public and two private schools from the region of Ottawa, Canada.Participants:Students in grades 7–12.Results:Parallel multiple mediation analyses revealed that more time spent watching TV at baseline is associated with higher z-BMI at T3 (total effect; B = 0·19, se = 0·07, P = 0·01, 95 % CI 0·05, 0·34), but no relationships were observed for total ST exposure or other types of ST and z-BMI. Disordered eating did not mediate the positive association between baseline TV viewing and z-BMI at T3.Conclusions:TV viewing was longitudinally associated with higher z-BMI in a community-based sample of adolescents, but disordered eating behaviours did not mediate this relationship. However, other non-pathological eating behaviours may mediate the association between ST and obesity and warrant further investigation. Finding suggests that targeting reduction in youth’s TV viewing may be an effective component in the prevention of childhood obesity.

Research paper thumbnail of Associations of the BDNF Val66Met Polymorphism With Body Composition, Cardiometabolic Risk Factors, and Energy Intake in Youth With Obesity: Findings From the HEARTY Study

Frontiers in Neuroscience, Nov 12, 2021

Research paper thumbnail of Two-month administration of methylphenidate improves olfactory sensitivity and suppresses appetite in individuals with obesity

Canadian Journal of Physiology and Pharmacology, 2021

Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methyl... more Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methylphenidate (MPH) increases brain dopamine levels and has been shown to reduce appetite and promote weight loss in patients with attention deficit hyperactivity disorder. The objectives of this study were to test the effect of MPH on olfaction, appetite, energy intake, and body weight (BW) on individuals with obesity. In a randomized, double-blind study, 12 participants (age 28.9 ± 6.7 years) with a body mass index (BMI) of 36.1 ± 4.5 kg/m2 were assigned to MPH (0.5 mg/kg) (n = 5) or placebo (n = 7) twice daily for 2 months. Appetite (visual analog scale), odour threshold (Sniffin’ Sticks®), energy intake (food menu), and BW (DEXA scan) were measured at day 1 and day 60. MPH intake significantly increased odour threshold scores (6.3 ± 1.4 vs. 9.4 ± 2.1 and 7.9 ± 2.3 vs. 7.8 ± 1.9, respectively; p = 0.029) versus placebo. There was a significantly greater suppression of appetite sensations ...

Research paper thumbnail of Effects of weight teasing and gender on body esteem in youth: A longitudinal analysis from the REAL study

Research paper thumbnail of Physical activity and cognition in children and youth: A systematic review

Journal of Exercise, Movement, and Sport (SCAPPS refereed abstracts repository), Oct 21, 2018

Research paper thumbnail of The Research on Eating and Adolescent Lifestyle (REAL) Study Protocol: A Shared Biopsychosocial Model for Predicting Eating Disorders and Obesity in Adolescents

This manuscript describes the rationale, design and methods of the Research on Eating and Adolesc... more This manuscript describes the rationale, design and methods of the Research on Eating and Adolescent Lifestyles Study (REAL), which from 2006-2013, aimed to test an integrative biopsychosocial model of cross-sectional and longitudinal predictors and developmental mechanisms for both eating disorders (EDs) and obesity in a large sample of Canadian youth. The present study examined predictors from four main areas of risk: biological (e.g. weight status, pubertal stage), environmental (e.g. societal influences), individual (e.g. self-perception), and eating and weight specific behaviors (e.g. disordered eating) to test direct and indirect paths for both ED and obesity simultaneously as outcomes. Participants were recruited based on a convenience sample from 43 urban and rural public schools, and data collection ran from 2006-2013. The cross sectional sample consisted of 3043 males and females in grades 7-12. The longitudinal sample was comprised of 1197 students in grades 7 and 9 who completed annual follow ups for 7 years. The REAL study is unique as it proposes a biopsychosocial model to explain EDs and obesity in adolescents under parallel processes within a single model, and is more integrative and comprehensive than previous models. Findings from this study were intended to inform prevention initiatives and further the understanding of the etiological similarities amongst EDs and obesity in a large sample of both male and female youth across adolescence.

Research paper thumbnail of Longitudinal association between movement behaviours and depressive symptoms among adolescents using compositional data analysis

Research paper thumbnail of Evaluating the psychometric properties of the parent-rated Strengths and Difficulties Questionnaire in a nationally representative sample of Canadian children and adolescents aged 6 to 17 years

Health Reports, Aug 19, 2020

Background: The Strengths and Difficulties Questionnaire (SDQ) is a brief measure of children's a... more Background: The Strengths and Difficulties Questionnaire (SDQ) is a brief measure of children's and adolescents' mental health. There are different versions of the questionnaire: a version for children and adolescents to complete by self-reporting, a version for parents and guardians to complete ("parent-rated"), and a version for teachers to complete. The purpose of this study was to examine the psychometric properties of the parent-rated SDQ with a nationally representative sample of Canadian children and adolescents. Data and methods: Data are from cycle 1 (2007 to 2009), cycle 2 (2009 to 2011), cycle 3 (2012 to 2013) and cycle 4 (2014 to 2015) of the Canadian Health Measures Survey. Data include 7,451 Canadian children and adolescents aged 6 to 17 years (49.3% female). Parents and guardians completed the SDQ by reflecting on their child's behaviour over the past six months. Factorial validity was examined via confirmatory factor analysis, which included testing the original five-factor SDQ model and alternative three-factor and higher-order models. Reliability was assessed through composite reliability scores. Measurement invariance across subgroups was also assessed. Results: The original five-factor (i.e., emotional symptoms, conduct problems, peer problems, hyperactivity and prosocial behaviour) SDQ fit the data satisfactorily, demonstrated evidence of reliability, and was invariant across sex (male vs. female), age (children vs. adolescents) and survey language (English vs. French). The higher-order solution fit the data acceptably, and the three-factor solution did not fit the data well. Discussion: The original five-factor, parent-rated SDQ demonstrates evidence of factorial validity and reliability as a population measure of mental health difficulties among Canadian children and adolescents.

Research paper thumbnail of Physical activity and brain structure, brain function, and cognition in children and youth: A systematic review of randomized controlled trials

Mental Health and Physical Activity, Mar 1, 2019

Research paper thumbnail of Systematic review of sedentary behaviour and health indicators in school-aged children and youth

International Journal of Behavioral Nutrition and Physical Activity, 2011

Research paper thumbnail of 24-HOUR Movement Guidelines and Suicidality Among Adolescents

Journal of Affective Disorders, Sep 1, 2020

BACKGROUND The 24-hour movement guidelines for children and youth recommend ≥60 min/day of modera... more BACKGROUND The 24-hour movement guidelines for children and youth recommend ≥60 min/day of moderate-to-vigorous physical activity, ≤2 h/day of screen time, 9-11 h/night of sleep for 11-13 years and 8-10 h/night for 14-17 years. The objectives of this study were to examine the associations between meeting combinations of the recommendations contained within the 24-hour movement guidelines for children and youth and suicidal ideation and suicide attempts, and test whether age and gender moderate these associations. METHODS Data on 10,183 students were obtained from the 2015-2017 Ontario Student Drug Use and Health Survey, a representative cross-sectional survey of Ontario students in grades 7-12 (mean [SD] age, 15.2 [1.8] years). RESULTS Suicidal ideation and suicide attempts were reported by 13.1% and 3.3% of students, respectively. Meeting individual recommendations or combinations of recommendations were differentially associated with suicidal ideation and suicide attempts between adolescent boys and girls and younger and older (three-way interactions statistically significant for both outcomes). Meeting all 3 recommendations was associated with lower odds of suicidal ideation (OR: 0.24, 95% CI: 0.09 - 0.69) and suicide attempts (OR: 0.08, 95% CI: 0.02 - 0.41) among boys aged 15 to 20 years, but not those aged 11 to 14 years nor girls in both age groups. LIMITATIONS The cross-sectional nature of the data precludes causal inferences and there is possibility of bias related to self-reports. CONCLUSIONS These findings suggest that adherence to the 24-hour movement guidelines among adolescents is related to lower odds of suicidality in older boys.

Research paper thumbnail of Electronic Maternal Health Survey

Research paper thumbnail of Effects of interactive video game cycling on overweight and obese adolescent health

Applied Physiology, Nutrition, and Metabolism, Dec 1, 2010

Research paper thumbnail of Screen Viewing and Diabetes Risk Factors in Overweight and Obese Adolescents

American Journal of Preventive Medicine, Apr 1, 2013

Sedentary behavior has been associated with deleterious cardiometabolic health indicators in adul... more Sedentary behavior has been associated with deleterious cardiometabolic health indicators in adults, but very little research has examined this relationship in youth. To examine the association between the duration and type of sedentary screen behavior with diabetes risk factors (fasting glucose, insulin, homeostasis model-insulin resistance [HOMA-IR], 2-hour postload glucose, hemoglobin A1c) in a sample of overweight and obese adolescents. A cross-sectional study of 307 overweight or obese adolescents aged 14-18 years (90 boys, 217 girls) assessed at baseline of a lifestyle intervention for weight control conducted from 2005 to 2010. Sedentary screen behaviors, defined as hours per day spent watching TV, playing seated video games, recreational computer use, and total screen time were measured by self-report. Data were analyzed using linear regression analyses in 2012. TV viewing was the only type of sedentary screen behavior associated with elevated diabetes risk factors before and after adjustment for confounders. Specifically, TV viewing remained positively associated with fasting insulin (adjusted r=0.11, β=0.10, p=0.048) and HOMA-IR (adjusted r=0.11, β=0.10, p=0.05) after adjustment for age, gender, waist-to-hip ratio, caloric intake, percentage of intake in carbohydrates, physical activity duration, and physical activity intensity. TV watching may be independently associated with an increase in diabetes risk factors in a high-risk sample of overweight and obese adolescents. These findings provide support for interventions designed to reduce time spent watching TV as a possible means to attenuating diabetes risk factors in this high-risk population.

Research paper thumbnail of Associations between the Canadian 24 h movement guidelines and different types of bullying involvement among adolescents

Child Abuse & Neglect, Oct 1, 2020

Research paper thumbnail of Combinations of physical activity, sedentary time, and sleep duration and their associations with depressive symptoms and other mental health problems in children and adolescents: a systematic review

International Journal of Behavioral Nutrition and Physical Activity, Jun 5, 2020

Research paper thumbnail of The Canadian 24-Hour Movement Guidelines and Psychological Distress among Adolescents: Les Directives canadiennes en matière de mouvement sur 24 heures et la détresse psychologique chez les adolescents

The Canadian Journal of Psychiatry, Nov 27, 2020

Research paper thumbnail of Brain on Fire: Incentive Salience, Hedonic Hot Spots, Dopamine, Obesity, and Other Hunger Games

Annual Review of Nutrition, Aug 21, 2017

This review examines human feeding behavior in light of psychological motivational theory and hig... more This review examines human feeding behavior in light of psychological motivational theory and highlights the importance of midbrain dopamine (DA). Prospective evidence of both reward surfeit and reward deficit pathways to increased body weight are evaluated, and we argue that it is more complex than an either/or scenario when examining DA's role in reward sensitivity, eating, and obesity. The Taq1A genotype is a common thread that ties the contrasting models of DA reward and obesity; this genotype related to striatal DA is not associated with obesity class per se but may nevertheless confer an increased risk of weight gain. We also critically examine the concept of so-called food addiction, and despite growing evidence, we argue that there is currently insufficient human data to warrant this diagnostic label. The surgical and pharmacological treatments of obesity are discussed, and evidence is presented for the selective use of DA-class drugs in obesity treatment.

Research paper thumbnail of 24-Hour Movement Behaviors and Impulsivity

Pediatrics, Sep 1, 2019

BACKGROUND: The objective of this study was to examine individual and concurrent associations bet... more BACKGROUND: The objective of this study was to examine individual and concurrent associations between meeting the Canadian 24-Hour Movement Guidelines for Children and Youth (9–11 hours of sleep per night, ≤2 hours of recreational screen time (ST) per day, and at least 60 minutes of moderate to vigorous physical activity per day) and dimensions of impulsivity. METHODS: Data from this cross-sectional observational study were part of the first annual curated release of the Adolescent Brain Cognitive Development Study. Participants included 4524 children between the ages of 8 and 11 years. RESULTS: In analyses, it was shown that adherence to individual movement behavior recommendations as well as combinations of adherence to movement behavior recommendations were associated with each dimension of impulsivity. Meeting all 3 movement behavior recommendations was associated with lower positive urgency (95% confidence interval [CI]: −0.12 to −0.05), negative urgency (95% CI: −0.04 to −0.08), Behavioral Inhibition System (95% CI: −0.08 to −0.01), greater perseverance (95% CI: 0.09 to 0.15), and better scores on delay-discounting (95% CI: 0.57 to 0.94). Meeting the ST and sleep recommendations was associated with less impulsive behaviors on all dimensions of impulsivity: negative urgency (95% CI: −0.20 to −0.10), positive urgency (95% CI: −0.16 to −0.08), perseverance (95% CI: 0.06 to 0.15), Behavioral Inhibition System (95% CI: −0.15 to −0.03), Behavioral Activation System (BAS) reward responsiveness (95% CI: −0.04 to −0.05), BAS drive (95% CI: −0.14 to −0.06), BAS fun-seeking (95% CI: −0.15 to −0.17), and delay-discounting task (95% CI: 0.68 to 0.97). CONCLUSIONS: Findings support efforts to determine if limiting recreational ST while promoting adequate sleep enhances the treatment and prevention of impulsivity-related disorders.

Research paper thumbnail of The association between social media use and physical activity among Canadian adolescents: a Health Behaviour in School-aged Children (HBSC) study

Canadian Journal of Public Health-revue Canadienne De Sante Publique, Mar 15, 2023

Research paper thumbnail of Mediating role of disordered eating in the relationship between screen time and BMI in adolescents: longitudinal findings from the Research on Eating and Adolescent Lifestyles (REAL) study

Public Health Nutrition, Aug 13, 2020

Objective:This study investigated whether the duration and type of screen time (ST) (TV viewing, ... more Objective:This study investigated whether the duration and type of screen time (ST) (TV viewing, recreational computer use, video gaming) is longitudinally associated with z-BMI and if these relationships are mediated by disordered eating (emotional, restrained).Design:At baseline, participants were n 1197 (T1; 60 % female) adolescents (mean age = 13·51 years) who completed surveys over 2 years. ST was assessed by a self-reported measure created by the investigative team, while emotional and restrained eating was measured by the Dutch Eating Behaviour Questionnaire (DEB-Q). Height and weight were objectively measured to quantify z-BMI.Setting:Thirty-one public and two private schools from the region of Ottawa, Canada.Participants:Students in grades 7–12.Results:Parallel multiple mediation analyses revealed that more time spent watching TV at baseline is associated with higher z-BMI at T3 (total effect; B = 0·19, se = 0·07, P = 0·01, 95 % CI 0·05, 0·34), but no relationships were observed for total ST exposure or other types of ST and z-BMI. Disordered eating did not mediate the positive association between baseline TV viewing and z-BMI at T3.Conclusions:TV viewing was longitudinally associated with higher z-BMI in a community-based sample of adolescents, but disordered eating behaviours did not mediate this relationship. However, other non-pathological eating behaviours may mediate the association between ST and obesity and warrant further investigation. Finding suggests that targeting reduction in youth’s TV viewing may be an effective component in the prevention of childhood obesity.

Research paper thumbnail of Associations of the BDNF Val66Met Polymorphism With Body Composition, Cardiometabolic Risk Factors, and Energy Intake in Youth With Obesity: Findings From the HEARTY Study

Frontiers in Neuroscience, Nov 12, 2021

Research paper thumbnail of Two-month administration of methylphenidate improves olfactory sensitivity and suppresses appetite in individuals with obesity

Canadian Journal of Physiology and Pharmacology, 2021

Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methyl... more Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methylphenidate (MPH) increases brain dopamine levels and has been shown to reduce appetite and promote weight loss in patients with attention deficit hyperactivity disorder. The objectives of this study were to test the effect of MPH on olfaction, appetite, energy intake, and body weight (BW) on individuals with obesity. In a randomized, double-blind study, 12 participants (age 28.9 ± 6.7 years) with a body mass index (BMI) of 36.1 ± 4.5 kg/m2 were assigned to MPH (0.5 mg/kg) (n = 5) or placebo (n = 7) twice daily for 2 months. Appetite (visual analog scale), odour threshold (Sniffin’ Sticks®), energy intake (food menu), and BW (DEXA scan) were measured at day 1 and day 60. MPH intake significantly increased odour threshold scores (6.3 ± 1.4 vs. 9.4 ± 2.1 and 7.9 ± 2.3 vs. 7.8 ± 1.9, respectively; p = 0.029) versus placebo. There was a significantly greater suppression of appetite sensations ...