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Bariatric surgery results in increased intestinal secretion of hormones GLP-1 and anorexigenic PYY, which is believed to contribute to the clinical efficacy associated with the procedure. This observation raises the question whether combination treatment with gut hormone analogs might recapitulate the efficacy and mitigate the significant risks associated with surgery. Despite PYY demonstrating excellent efficacy and safety profiles with regard to food intake reduction, weight loss, and glucose control in preclinical animal models, PYY-based therapeutic development remains challenging given a low serum stability and half-life for the native peptide. Here, combined peptide stapling and PEG-fatty acid conjugation affords potent PYY analogs with >14 h rat half-lives, which are expected to translate into a human half-life suitable for once-weekly dosing. Excellent efficacy in glucose control, food intake reduction, and weight loss for lead candidate 22 in combination with our previously reported long-acting GLP-1 analog is demonstrated in a diet-induced obesity mouse model.

Objective: To investigate the independent associations between objectively measured levels of movement intensity (i.e., time spent sedentary and at light, moderate and vigorous intensities) and indicators of adiposity in a cohort of Canadian children., Methods: A cross-sectional study was conducted in 550 Caucasian children aged 8-10 years with at least one obese biological parent. Physical activity and sedentary time (accelerometer over 7 d) and indicators of adiposity (% body fat measured by dual-energy X-ray absorptiometry and waist-to-height ratio) were objectively measured. We examined the associations between levels of movement intensity and adiposity in multi-level linear regression models adjusted for age, sex, sleep duration, energy intake, sexual maturation, parental socioeconomic status and parental body mass index., Results: Objectively measured sedentary time was not associated with adiposity indicators in this cohort (unadjusted and adjusted models). However, moderate-to-vigorous physical activity (MVPA) was inversely associated with % body fat (adj. β = -0.047; P = 0.02) and waist-to-height ratio (adj. β = -0.071; P < 0.001), independent of sedentary time and other covariates. Additionally, we observed that children who did not accumulate ≥60 min d(-1) of MVPA were more likely to be overweight or obese compared to those who met the recommendation (odds ratio [OR] 2.22, 95% confidence interval [CI] 1.45-3.38). In contrast, there was no difference in the likelihood of being categorized as overweight or obese between those who met the recommendation of ≤2 h d(-1) of screen time and those who did not meet this recommendation (OR 1.27, 95% CI 0.75-2.01)., Conclusion: The present study suggests that MVPA is independently associated with adiposity indices in this sample of children while sedentary time is not. Future studies should examine the best approach to increase MVPA in children and youth., (© 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.)

Objective: To assess the feasibility of employing an ecologically guided childhood obesity relevant surveillance system., Methods: Cross-sectional qualitative and quantitative data were collected from 31 organizational representatives across 28 unique organizations and/or departments from three purposively sampled communities in the Capital Health Region in Alberta, Canada., Results: All the organizational representatives surveyed reported awareness of childhood obesity and 36% reported participation in child obesity initiatives. Data to support a surveillance system are available but not in a suitable format, and privacy legislation present significant barriers. Interest in developing and sustaining an ecologically based surveillance system was low (18%)., Conclusion: Due to the heterogeneity of available data and limited vision for the development and implementation of a surveillance system, the application of an ecologically based surveillance system relevant to childhood obesity may be constrained. Broad-based awareness of childhood obesity by a wide range of organizations could assist in establishing an effective coalition to address this issue over the long term by supporting the establishment of a surveillance system.

Obesity is a rapidly increasing public health problem, with surveillance most often based on self-reported values of height and weight. We conducted a systematic review to determine what empirical evidence exists regarding the agreement between objective (measured) and subjective (reported) measures in assessing height, weight and body mass index (BMI). Five electronic databases were searched to identify observational and experimental studies on adult populations over the age of 18. Searching identified 64 citations that met the eligibility criteria and examined the relationship between self-reported and directly measured height or weight. Overall, the data show trends of under-reporting for weight and BMI and over-reporting for height, although the degree of the trend varies for men and women and the characteristics of the population being examined. Standard deviations were large indicating that there is a great deal of individual variability in reporting of results. Combining the results quantitatively was not possible because of the poor reporting of outcomes of interest. Accurate estimation of these variables is important as data from population studies such as those included in this review are often used to generate regional and national estimates of overweight and obesity and are in turn used by decision makers to allocate resources and set priorities in health.

Objective: This study examined the relation among children's physical activity, sedentary behaviours, and body mass index (BMI), while controlling for sex, family structure, and socioeconomic status., Design: Epidemiological study examining the relations among physical activity participation, sedentary behaviour (video game use and television (TV)/video watching), and BMI on a nationally representative sample of Canadian children., Subjects: A representative sample of Canadian children aged 7-11 (N=7216) from the 1994 National Longitudinal Survey of Children and Youth was used in the analysis., Measurements: Physical activity and sport participation, sedentary behaviour (video game use and TV/video watching), and BMI measured by parental report., Results: Both organized and unorganized sport and physical activity are negatively associated with being overweight (10-24% reduced risk) or obese (23-43% reduced risk), while TV watching and video game use are risk factors for being overweight (17-44% increased risk) or obese (10-61% increased risk). Physical activity and sedentary behaviour partially account for the association of high socioeconomic status and two-parent family structure with the likelihood of being overweight or obese., Conclusion: This study provides evidence supporting the link between physical inactivity and obesity of Canadian children.

Objective: To assess changes in the prevalence of overweight and obesity among Canadian children and adults between 1981 and 1996 using recent recommendations for the classification of overweight and obesity., Design: Epidemiological study comparing the prevalence of overweight and obesity from the 1981 Canada Fitness Survey (CFS) to the 1996 National Longitudinal Survey of Children and Youth (NLSCY) and the 1996 National Population Health Survey (NPHS)., Subjects: Adults 20-64 y of age and children 7-13 y of age from the CFS, NLSCY and NPHS., Measurements: BMI was calculated from directly measured or self-reported body mass and height. For adults 20-64 y of age, overweight and obesity were defined as BMI > or = 25 kg/m2 and BMI > or = 30 kg/m2, respectively. Age- and sex-specific cut-off points for children that correspond to the adulthood categories were used to define overweight and obesity for children 7-13 y of age., Results: The prevalence of overweight increased from 48 to 57% among men and from 30 to 35% among women, while the prevalence of obesity increased from 9 to 14% in men and from 8 to 12% in women. The corresponding increases were from 11 to 33% in boys and from 13 to 27% in girls for overweight and from 2 to 10% in boys and from 2 to 9% in girls for obesity., Conclusion: The results indicate dramatic increases in the prevalence of both overweight and obesity in Canada over the last 15 y, and the problem is particularly pronounced among children.

Background: Various changes in society have created the opportunity for more sedentary behaviour and the consumption of food that is high in kilojoules, which may lead to a progressive increase in body mass over time. The purpose of this study was to examine secular changes in the body mass index (BMI) of Canadian children between 1981 and 1996., Methods: Nationally representative data from the 1981 Canada Fitness Survey, the 1988 Campbell's Survey on the Well-being of Canadians and the 1996 National Longitudinal Survey of Children and Youth were used in the analysis. Regression analyses were used to assess population changes in BMI from 1981 to 1996 for children aged 7-13 years. Changes in the distribution of BMI results were evaluated by plotting the residuals from regression analyses of BMI on age, assessed separately by sex, using the 1981 data as baseline. The proportions of children exceeding the 85th and 95th age- and sex-specific percentiles from the 1981 (baseline) data were also calculated., Results: Since 1981, BMI has increased at the rate of nearly 0.1 kg/m2 per year for both sexes at most ages, indicating a clear secular trend toward an increase in BMI of Canadian children. The prevalence of overweight among boys increased from 15% in 1981 to 28.8% in 1996 and among girls from 15% to 23.6%. The prevalence of obesity in children more than doubled over that period, from 5% to 13.5% for boys and 11.8% for girls., Interpretation: Secular trends indicate that Canadian children aged 7-13 years are becoming progressively overweight and obese.

Protein tyrosine phosphatase-1B (PTP-1B) has been implicated in the negative regulation of insulin signaling. Disruption of the mouse homolog of the gene encoding PTP-1B yielded healthy mice that, in the fed state, had blood glucose concentrations that were slightly lower and concentrations of circulating insulin that were one-half those of their PTP-1B+/+ littermates. The enhanced insulin sensitivity of the PTP-1B-/- mice was also evident in glucose and insulin tolerance tests. The PTP-1B-/- mice showed increased phosphorylation of the insulin receptor in liver and muscle tissue after insulin injection in comparison to PTP-1B+/+ mice. On a high-fat diet, the PTP-1B-/- and PTP-1B+/- mice were resistant to weight gain and remained insulin sensitive, whereas the PTP-1B+/+ mice rapidly gained weight and became insulin resistant. These results demonstrate that PTP-1B has a major role in modulating both insulin sensitivity and fuel metabolism, thereby establishing it as a potential therapeutic target in the treatment of type 2 diabetes and obesity.

Summary: Background: The relationship between children's adiposity and lifestyle behaviour patterns is an area of growing interest. Objectives: The objectives of this study are to identify clusters of children based on lifestyle behaviours and compare children's adiposity among clusters. Methods: Cross‐sectional data from the International Study of Childhood Obesity, Lifestyle and the Environment were used. Participants: the participants were children (9–11 years) from 12 nations (n = 5710). Measures: 24‐h accelerometry and self‐reported diet and screen time were clustering input variables. Objectively measured adiposity indicators were waist‐to‐height ratio, percent body fat and body mass index z‐scores. Analysis: sex‐stratified analyses were performed on the global sample and repeated on a site‐wise basis. Cluster analysis (using isometric log ratios for compositional data) was used to identify common lifestyle behaviour patterns. Site representation and adiposity were compared across clusters using linear models. Results: Four clusters emerged: (1) Junk Food Screenies, (2) Actives, (3) Sitters and (4) All‐Rounders. Countries were represented differently among clusters. Chinese children were over‐represented in Sitters and Colombian children in Actives. Adiposity varied across clusters, being highest in Sitters and lowest in Actives. Conclusions: Children from different sites clustered into groups of similar lifestyle behaviours. Cluster membership was linked with differing adiposity. Findings support the implementation of activity interventions in all countries, targeting both physical activity and sedentary time. [ABSTRACT FROM AUTHOR]

The purposes of this study were to: (i) provide contemporary estimates of the prevalence of abdominal obesity, as assessed by waist circumference (WC), in Canadian adolescents and adults; (ii) provide estimates of the prevalence of abdominal obesity within normal weight, overweight and obese body mass index categories and (iii) examine secular changes in abdominal obesity. Data were based on three national health surveys conducted in 1981, 1988 and 2007-2009. WC was measured at the mid-point between the last rib and iliac crest in all three surveys. The prevalence of Canadians with abdominal obesity increased with age and was higher in females than in males. In 12- to 19-year-old adolescents, the estimated prevalence of abdominal obesity was 1.8% in 1981, 2.4% in 1988 and 12.8% in 2007-2009. The corresponding values for 20- to 69-year-old adults were 11.4%, 14.2% and 35.6%. Between 1981 and 2007-2009, mean WC values increased by 4.2 cm in adolescent males, 6.7 cm in adolescent females, 6.5 cm in men and 10.6 cm in women. Within the 2007-2009 survey, 2.6% of normal weight adults had abdominal obesity, 35.3% of overweight adults had abdominal obesity and 93.0% of obese adults had abdominal obesity. [ABSTRACT FROM AUTHOR]

Obesity is a rapidly increasing public health problem, with surveillance most often based on self-reported values of height and weight. We conducted a systematic review to determine what empirical evidence exists regarding the agreement between objective (measured) and subjective (reported) measures in assessing height, weight and body mass index (BMI). Five electronic databases were searched to identify observational and experimental studies on adult populations over the age of 18. Searching identified 64 citations that met the eligibility criteria and examined the relationship between self-reported and directly measured height or weight. Overall, the data show trends of under-reporting for weight and BMI and over-reporting for height, although the degree of the trend varies for men and women and the characteristics of the population being examined. Standard deviations were large indicating that there is a great deal of individual variability in reporting of results. Combining the results quantitatively was not possible because of the poor reporting of outcomes of interest. Accurate estimation of these variables is important as data from population studies such as those included in this review are often used to generate regional and national estimates of overweight and obesity and are in turn used by decision makers to allocate resources and set priorities in health. [ABSTRACT FROM AUTHOR]

Background: Various changes in society have created the opportunity for more sedentary behaviour and the consumption of food that is high in kilojoules, which may lead to a progressive increase in body mass over time. The purpose of this study was to examine secular changes in the body mass index (BMI) of Canadian children between 1981 and 1996.Methods: Nationally representative data from the 1981 Canada Fitness Survey, the 1988 Campbell's Survey on the Well-being of Canadians and the 1996 National Longitudinal Survey of Children and Youth were used in the analysis. Regression analyses were used to assess population changes in BMI from 1981 to 1996 for children aged 7-13 years. Changes in the distribution of BMI results were evaluated by plotting the residuals from regression analyses of BMI on age, assessed separately by sex, using the 1981 data as baseline. The proportions of children exceeding the 85th and 95th age- and sex-specific percentiles from the 1981 (baseline) data were also calculated.Results: Since 1981, BMI has increased at the rate of nearly 0.1 kg/m2 per year for both sexes at most ages, indicating a clear secular trend toward an increase in BMI of Canadian children. The prevalence of overweight among boys increased from 15% in 1981 to 28.8% in 1996 and among girls from 15% to 23.6%. The prevalence of obesity in children more than doubled over that period, from 5% to 13.5% for boys and 11.8% for girls.Interpretation: Secular trends indicate that Canadian children aged 7-13 years are becoming progressively overweight and obese. [ABSTRACT FROM AUTHOR]