Children and youth do not compensate for an imposed bout of prolonged sitting by reducing subsequent food intake or increasing physical activity levels: a randomised cross-over study

Abstract The behavioural impact of an imposed bout of prolonged sitting is yet to be investigated in the paediatric population. The objective of the present study was to determine the acute effect of prolonged sitting on ad libitum food intake and spontaneous physical activity (PA) levels in healthy children and youth. A total of twenty healthy youth (twelve males and eight females) aged 10 -14 years, with a mean BMI of 18·6 (SD 4·3) kg/m 2 , were exposed to three experimental conditions in a random order: (1) a day of uninterrupted sitting (Sedentary); (2) a day of sitting interrupted with a 2 min light-intensity walk break every 20 min (Breaks); (3) a day of sitting interrupted with a 2 min lightintensity walk break every 20 min as well as 2 £ 20 min of moderate-intensity PA (Breaks þ PA). Food intake (ad libitum buffet meal) and PA (accelerometry for 24 h) were assessed following exposure to each experimental condition. Despite significant differences in sedentary behaviour and activity levels during the three in-laboratory sessions (all P, 0·01), we did not observe any differences in ad libitum food intake immediately following exposure to each experimental condition or any changes in the levels of sedentary behaviour or PA in the 24 h following exposure to each experimental condition (all P.0·25). These findings suggest that children and youth may not compensate for an imposed bout of sedentary behaviour by reducing subsequent food intake or increasing PA levels

No association of the dopamine D2 receptor genetic bilocus score (rs1800497/rs1799732) on food addiction and food reinforcement in Chilean adults

Purpose: Different systems regulate food intake. In the reward system, dopamine (DA) is the main neurotransmitter, and a variety of genetic variants (rs1799732 and rs1800497) are associated with addiction. Addiction is a highly polygenic disease, where each allelic variant adds a small amount of vulnerability. Polymorphisms rs1799732 and rs1800497 are associated with eating behavior and hedonic hunger, but links to food addiction remain unclear.Aim: To evaluate the association between the bilocus profile (rs1799732-rs1800497) of the dopaminergic pathway with food reinforcement and food addiction in Chilean adults.Methods: A cross-sectional study recruited a convenience sample of 97 obese, 25 overweight, and 99 normal-weight adults (18–35 years). Anthropometric measurements were performed by standard procedures and eating behavior was assessed using the: Food Reinforcement Value Questionnaire (FRVQ) and Yale Food Addiction scale (YFAS). The DRD2 genotypes were determined by TaqMan assays (rs1800497 and rs1799732). A bilocus composite score was calculated.Results: In the normal weight group, individuals who were heterozygous for the rs1977932 variant (G/del) showed higher body weight (p-value 0.01) and abdominal circumference (p-value 0.01) compared to those who were homozygous (G/G). When analyzing rs1800497, a significant difference in BMI was observed for the normal weight group (p-value 0.02) where heterozygous showed higher BMI. In the obese group, homozygous A1/A1 showed higher BMI in comparison to A1/A2 and A2/A2 (p-value 0.03). Also, a significant difference in food reinforcement was observed in the rs1800497, where homozygous for the variant (A1A1) show less reinforcement (p-value 0.01).In relation to the bilocus score in the total sample, 11% showed “very low dopaminergic signaling”, 24.4% were “under”, 49.7% showed “intermediate signaling”, 12.7% showed “high” and 1.4% showed “very high”. No significant genotypic differences were observed in food reinforcement and food addiction by bilocus score.Conclusions: The results indicate that the genetic variants rs1799732 and rs1800497 (Taq1A) were associated with anthropometric measurements but not with food addiction or food reinforcement in Chilean university students. These results suggest that other genotypes, such as rs4680 and rs6277, which affect DA signaling capacity through a multilocus composite score, should be studied. Level V: Evidence obtained from a cross-sectional descriptive study

Screening for depression in children and adolescents in primary care or non-mental health settings: a systematic review update

Abstract Background The transition from childhood to adolescence is associated with an increase in rates of some psychiatric disorders, including major depressive disorder, a debilitating mood disorder. The aim of this systematic review is to update the evidence on the benefits and harms of screening for depression in primary care and non-mental health clinic settings among children and adolescents. Methods This review is an update of a previous systematic review, for which the last search was conducted in 2017. We searched Ovid MEDLINE® ALL, Embase Classic+Embase, PsycINFO, Cochrane Central Register of Controlled Trials, and CINAHL on November 4, 2019, and updated on February 19, 2021. If no randomized controlled trials were found, we planned to conduct an additional search for non-randomized trials with a comparator group. For non-randomized trials, we applied a non-randomized controlled trial filter and searched the same databases except for Cochrane Central Register of Controlled Trials from January 2015 to February 2021. We also conducted a targeted search of the gray literature for unpublished documents. Title and abstract, and full-text screening were completed independently by pairs of reviewers. Results In this review update, we were unable to find any randomized controlled studies that satisfied our eligibility criteria and evaluated the potential benefits and harms of screening for depression in children and adolescents. Additionally, a search for non-randomized trials yielded no studies that met the inclusion criteria. Conclusions The findings of this review indicate a lack of available evidence regarding the potential benefits and harms of screening for depression in children and adolescents. This absence of evidence emphasizes the necessity for well-conducted clinical trials to evaluate the effectiveness of depression screening among children and adolescents in primary care and non-mental health clinic settings. Systematic review registration PROSPERO CRD42020150373

THE RELATIVE REINFORCING VALUE OF SNACK FOOD IS A SIGNIFICANT PREDICTOR OF FAT LOSS IN WOMEN WITH OVERWEIGHT OR OBESITY

Reinforcing Relative Value (RRV) of food and impulsivity are associated with energy intake and obesity. The study investigated the degree to which changes in RRV and impulsivity independently or interactively predict change in body weight and composition in women with overweight or obesity engaged in either a fast or in a slow weight loss programs. Body weight, body composition, Impulsivity (Barratt Impulsiveness Scale), RRV snack (computerized Behavioural Choice Task) were measured at baseline and post-intervention in 30 women with obesity undergoing either slow (n= 14 -500 kcal/day, 20 weeks) or fast n=16 (-1000kcal/day, 10 weeks) weight reduction. No group*time effects were noted on body composition, impulsivity or RRV, so participants from both groups were pooled for analysis. Multiple regression analyses indicated that none of the impulsivity variables predicted weight- or fat mass (FM) loss. However, Δ RRV snack predicted ΔFM (r=0.40, P=0.046), whereby greater increases in RRV snack were associated with less FM loss. Results indicate that different rates of weight loss do not differentially affect RRV snack or impulsivity traits. However, changes in RRV snack predicted FM loss, suggesting that dietary interventions that either mitigate increases or foster reductions in the RRV snack may yield greater reductions in adiposity. Trial Registration clinicaltrials.gov identifier: NCT04866875 NOVELTY POINTS • No differences in RRV of food were noted between fast and slow weight loss • Weight loss from combined fast and slow groups led to a moderate-sized reduction in the total impulsivity • Greater diet-induced increases in RRV snack was associated with less body fat-lossThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Physical Activity Promotion in the Preschool Years: A Critical Period to Intervene

The primary aim of this paper is to provide a rationale for the necessity of intervening with a physical activity intervention in the preschool years and why the daycare environment is amenable to such intervention. We also review the prevalence of physical activity, sedentary behaviour and obesity in the preschool population and the impact that these lifestyle behaviours and conditions have on the health of preschool aged children, as secondary objectives. Moreover we discuss implications for intervention and research using a “lessons learned” model based on our research team’s experience of conducting a randomized controlled trial aimed at increasing physical activity, reducing sedentary behaviour and improving motor skill development and body composition in preschoolers. Lastly, we make conclusions based on the literature and highlight issues and directions that need to be addressed in future research in order to maximize health promotion and chronic disease prevention in the pediatric population

Problem Technology Use, Academic Performance, and School Connectedness among Adolescents

Background: Little is known about the association between problem technology use in adolescents and school-related outcomes. The purpose of this study was to determine the prevalence of problem technology use and examine its association with academic performance and school connectedness in a sample of students across Ontario, Canada. Methods: Self-reported data from a sample of 4837 students in grades 9 to 12 (mean age: 15.9 years; 49.5% females) were cross-sectionally analyzed. Ordered logistic regression models were adjusted for important covariates. Results: We found that 35.8% of students used their screen device for at least 5 h a day and about 18.6% had moderate-to-serious symptoms of problem technology use, a prevalence that was higher in females (22.4%) than males (14.9%). Heavy technology use was differentially associated with lower academic performance and lower levels of school connectedness in males and females. Having moderate-to-serious symptoms of problem technology use was associated with lower academic performance among males (AOR = 0.68, 95% CI = 0.53–0.87) and females (AOR = 0.66, 95% CI = 0.52–0.84). It was also associated with less school connectedness in both males (AOR = 0.65, 95% CI = 0.50–0.86) and females (AOR = 0.63, 95% CI = 0.51–0.78). Conclusion: Excessive use and problem technology use are highly prevalent among secondary school students, and they are associated with lower academic performance and lower levels of school connectedness

Fasting for 24 hours heightens reward from food and food-related cues.

We examined the impact of a 24 hour complete fast (vs. fed state) on two measures of food reward: 1) 'wanting', as measured by response to food images and by the relative-reinforcing value of food (RRV), and 2) 'liking', as measured by response to food images and the hedonic evaluation of foods consumed.Utilizing a randomized crossover design, 15 subjects (9 male; 6 female) aged 28.6±4.5 yrs with body mass index 25.3±1.4 kg/m(2) were randomized and counterbalanced to normal feeding (FED) and 24-hour fast (FASTED) conditions. Trait characteristics were measured with the Three Factor Eating Questionnaire. Two computer tasks measured food reward: 1) RRV progressive ratio task, 2) explicit 'liking' and 'wanting' (Leeds Food Preference Questionnaire, LFPQ). Also measured were ad libitum energy intake (EI; buffet) and food 'liking' (visual analogue scale) of personalized stimuli.There were no significant anthropometric changes between conditions. Appetite scores, hedonic ratings of 'liking', and ad libitum EI all significantly increased under the FASTED condition (p<0.05). Under the FASTED condition there were significant increases in the RRV of snack foods; similarly, explicit 'wanting' and 'liking' significantly increased for all food categories. 'Liking' of sweet foods remained high across-meals under FASTED, but savory foods decreased in hedonic saliency.Relative to a fed state, we observed an increase in hedonic ratings of food, the rewarding value of food, and food intake after a 24 hr fast. Alliesthesia to food and food cues is suggested by heightened hedonic ratings under the FASTED condition relative to FED