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Chaput J.-P.,Eastern Research Group | Despres J.-P.,Quebec Heart Institute | Bouchard C.,Pennington Biomedical Research Center | Tremblay A.,Laval University
International Journal of Obesity | Year: 2012

The objective of this longitudinal, observational study was to verify whether a favorable change in sleep duration over 6 years could impact objective indicators of adiposity in adults aged 18-64 years. Short-duration sleepers (≤6 h per day; n = 43) at baseline were divided into two groups: (i) those who increased their sleep duration to a 'healthy' length of 7-8 h per day at year 6 (mean increase: 1.52±0.66 h per day; n=23); and (ii) those who maintained their short sleep duration habits (mean change:-0.11±0.38 h per day; n = 20). Adult individuals who reported sleeping 7-8 h per day at both baseline and year 6 (n = 173) were used as a control group. Change in adiposity indicators for each sleep-duration group was compared by analysis of covariance. We observed that the two short-sleep-duration groups had similar baseline characteristics. However, short-duration sleepers who maintained their short sleep duration experienced a greater increase in body mass index (BMI) (difference: 1.1±0.36 kg m -2, P<0.05) and fat mass (difference: 2.4±0.64 kg, P<0.05) over the 6-year follow-up period than short-duration sleepers who increased their sleep duration, even after adjustment for relevant covariates. We did not observe any significant difference in adiposity changes between the control group and short-duration sleepers who increased their sleep duration. This study suggests for the first time that shifting sleep duration from a short to a healthier length is associated with an attenuation of fat mass gain.© 2012 Macmillan Publishers Limited. All rights reserved.


Chaput J.-P.,Eastern Research Group | Doucet E.,University of Ottawa | Tremblay A.,Laval University
Obesity Reviews | Year: 2012

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a 'collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population. © 2012 The Authors. obesity reviews © 2012 International Association for the Study of Obesity.


Winslow D.H.,Eastern Research Group | Bowden C.H.,VIVUS | DiDonato K.P.,Eastern Research Group | McCullough P.A.,Eastern Research Group
Sleep | Year: 2012

Study Objectives: To evaluate safety and efficacy of phentermine 15 mg plus extended-release topiramate 92 mg for treatment of moderate to severe obstructive sleep apnea (OSA) in obese adults. Design: This phase 2, randomized, double-blind, placebo-controlled study included 2-week screening and 28-week treatment periods. Overnight polysomnography was performed at baseline, Week 8, and Week 28. Setting: Single-center study conducted from August 2008 to September 2009. Participants: Forty-five subjects with moderate to severe OSA not receiving positive airway pressure (PAP) treatment with body mass index of 30-40 kg/m2. Interventions: Subjects were randomized to receive placebo (n = 23) or phentermine 15 mg plus extended-release topiramate 92 mg (n = 22). Both groups received lifestyle-modification counseling. Measurements and Results: Primary endpoint, change in apnea-hypopnea index (AHI), significantly favored phentermine 15 mg plus extendedrelease topiramate 92 mg (-31.5 events/h, 95% CI: -40.0, -22.9) over placebo (-16.6 events/h, 95% CI: -25.0, -8.2) at Week 28 (P = 0.0084). At Week 28, there was a 10.2% (95% CI: -12.7, -7.6; 10.8 kg, 95% CI: -13.5, -8.0) mean decrease in weight in the phentermine 15 mg plus extendedrelease topiramate 92 mg group compared with 4.3% (95% CI: -6.6, -2.0; 4.7 kg, 95% CI: -7.2, -2.2) in the placebo group (P = 0.0006) and a positive, significant (P = 0.0003) correlation between percent change in weight and change in AHI. Significant improvements in overnight oxygen saturation and reduction in blood pressure compared with placebo were observed. Phentermine 15 mg plus extended-release topiramate 92 mg was well tolerated with low adverse event rates. Conclusions: Phentermine 15 mg plus extended-release topiramate 92 mg induced significant weight reductions and concomitant improvements in OSA and related symptoms vs placebo. This suggests weight loss mediated by phentermine 15 mg plus extended-release topiramate 92 mg may be useful in treatment of moderate to severe OSA in obese subjects unable or unwilling to comply with PAP treatment.


Thivel D.,Clermont University | Thivel D.,Eastern Research Group | Chaput J.-P.,Eastern Research Group | Chaput J.-P.,University of Ottawa
Sports Medicine | Year: 2014

The effect of physical activity on energy balance is not restricted to its induced energy expenditure but also affects the control of energy intake and appetite. Although it is now clear that physical exercise affects subsequent energy intake and appetite, the mechanisms involved remain uncertain. Most previous studies have assessed both post-exercise energy intake and appetite but mainly focussed their analyses on food consumption, and it remains unclear whether changes in appetite provide an accurate reflection of changes in energy intake. This brief review aims to analyse conjointly the effective energy intake and appetite sensation responses to acute exercise in children and adolescents to examine whether or not these responses to exercise are coupled. After an overview of the available literature, we conclude that acute exercise has an uncoupling effect on energy intake and appetite sensations in both lean and overweight/obese youth. Although methodological issues between studies can be highlighted, lack of consideration of inter-individual variability in terms of energy intake and appetite could be one of the main explanations for such a conclusion. It now appears necessary to further consider the impact of acute exercise and then chronic physical activity on an individual basis in the regulation of energy balance to prescribe successful weight loss programmes. © 2014 Springer International Publishing Switzerland.


Gribbon A.,Eastern Research Group | McNeil J.,University of Ottawa | Jay O.,University of Sydney | Tremblay M.S.,Eastern Research Group | Chaput J.-P.,Eastern Research Group
American Journal of Clinical Nutrition | Year: 2015

Background: Active video games (AVGs) have been shown to acutely increase energy expenditure when compared with seated video games; however, the influence of AVGs on compensatory adjustments in energy intake and expenditure is largely unknown. Objective: The aim was to examine the acute effects of AVGs on energy intake and expenditure. Design: With the use of a randomized crossover design, 26 male adolescents (mean ± SD age: 14.5 ± 1.4 y) completed three 1-h experimental conditions: resting control, seated video game play (Xbox 360; Microsoft), and AVG play (Kinect Adventures on Xbox 360) followed by an ad libitum lunch. A validated food menu was used to assess food intake immediately after the conditions and for the remainder of the day, and a dietary record was used for the subsequent 3-d period. Energy expenditure was measured by using portable indirect calorimetry throughout each experimental condition, and an accelerometer was used to assess the subsequent 3-d period. Appetite sensations were assessed by using visual analog scales at different time points during the testing day. The primary outcomes were acute (immediately after the conditions and 24-h) and short-term (3-d) energy intake and expenditure. Results: Energy expenditure was significantly higher (∼145%; P < 0.001) during the AVG condition than during the resting control and seated video game conditions; however, no significant differences in energy expenditure were observed 24 h (∼6%; P > 0.49) and 3 d after the experimental conditions (∼3%; P > 0.82). No significant differences were observed in absolute energy intake immediately after the conditions (∼2%; P > 0.94) or in absolute energy intake 24 h (∼5%; P > 0.63) and 3 d (∼9%; P > 0.53) after the experimental conditions. Finally, appetite sensations were similar between conditions at all time points (P > 0.05). Conclusions: The increase in energy expenditure promoted by a single session of Kinect AVG play is not associated with increased food intake but is compensated for after the intervention, resulting in no measurable change in energy balance after 24 h. These results suggest that the potential of Kinect to reduce the energy gap underlying weight gain is offset within 24 h in male adolescents. This trial was registered at clinicaltrials.gov as NCT01655901. © 2015 American Society for Nutrition.


Shields M.,Health Information and Research Division | Tremblay M.S.,Eastern Research Group
International Journal of Pediatric Obesity | Year: 2010

Objective. This article compares prevalence estimates of excess weight among Canadian children and youth according to three sets of body mass index (BMI) reference cut-points. The cut-points are based on growth curves generated by the World Health Organization (WHO), the International Obesity Task Force (IOTF), and the US Centers for Disease Control (CDC). A secondary objective is to compare estimates by method of data collection. Methods. Prevalence estimates of overweight and obesity were produced for 2- to 17-year-olds using the three sets of BMI cut-points. Estimates are based on data from 8 661 respondents from the 2004 Canadian Community Health Survey and 1 840 respondents from the 1978/79 Canada Health Survey. In both surveys, the height and weight of children were measured. Results. The 2004 prevalence estimate for the combined overweight/obese category is higher (35%) when based on the WHO cut-points compared with the IOTF (26%) or CDC (28%) cut-points. Estimates of the prevalence of obesity are similar based on WHO and CDC cut-points (13%), but lower when based on IOTF cut-points (8%). Absolute differences in excess weight estimates between 1978/79 and 2004 are similar based on the three sets of cut-points, but the relative increase is greater when based on the IOTF cut-points. Estimates vary substantially by method of data collection. Conclusion. When interpreting prevalence estimates of overweight and obesity for children and youth, it is important to consider the definitions used and the method of data collection. © 2010 Informa UK Ltd.


Chaput J.-P.,Eastern Research Group
Physiology & behavior | Year: 2014

There is increasing evidence showing that sleep has an influence on eating behaviors. Short sleep duration, poor sleep quality, and later bedtimes are all associated with increased food intake, poor diet quality, and excess body weight. Insufficient sleep seems to facilitate the ingestion of calories when exposed to the modern obesogenic environment of readily accessible food. Lack of sleep has been shown to increase snacking, the number of meals consumed per day, and the preference for energy-rich foods. Proposed mechanisms by which insufficient sleep may increase caloric consumption include: (1) more time and opportunities for eating, (2) psychological distress, (3) greater sensitivity to food reward, (4) disinhibited eating, (5) more energy needed to sustain extended wakefulness, and (6) changes in appetite hormones. Globally, excess energy intake associated with not getting adequate sleep seems to be preferentially driven by hedonic rather than homeostatic factors. Moreover, the consumption of certain types of foods which impact the availability of tryptophan as well as the synthesis of serotonin and melatonin may aid in promoting sleep. In summary, multiple connections exist between sleep patterns, eating behavior and energy balance. Sleep should not be overlooked in obesity research and should be included as part of the lifestyle package that traditionally has focused on diet and physical activity. © 2013.


Tremblay A.,Laval University | Royer M.-M.,Laval University | Chaput J.-P.,Eastern Research Group | Doucet E.,University of Ottawa
International Journal of Obesity | Year: 2013

The decrease in energy expenditure that occurs during weight loss is a process that attenuates over time the impact of a restrictive diet on energy balance up to a point beyond which no further weight loss seems to be possible. For some health professionals, such a diminished energy expenditure is the normal consequence of a progressive decrease in the motivation to exercise over the course of a weight-reducing program. Another explanation of decreased energy needs during weight loss is the decrease in body energy stores (that is, fat mass and muscle mass) and its related obligatory costs of living. Many studies have also documented the existence of adaptive thermogenesis in the context of weight loss, which represents a greater-than-predicted decrease in energy expenditure. In this paper, we pursue the analysis of this phenomenon by demonstrating that an adaptive decrease in thermogenesis can have a major role in the occurrence of resistance to further lose fat in weight-reduced obese individuals. Evidence is also presented to support the idea of greater hunger sensations in individuals displaying more pronounced thermogenic changes. Finally, as the decrease in thermogenesis persists over time, it is also likely associated with a greater predisposition to body-weight regain after weight loss. Globally, these observations suggest that the adaptive reduction in thermogenesis that accompanies a prolonged negative energy balance is a major determinant of the ability to spontaneously lose body fat. © 2013 Macmillan Publishers Limited.


Chaput J.-P.,Eastern Research Group | Tremblay A.,Laval University
Obesity Facts | Year: 2012

Objective: To verify whether sleep quantity and quality at baseline predict the magnitude of fat loss in adults subjected to moderate caloric restriction. Methods: A total of 123 overweight and obese men and women (age, 41.1 ± 6.0 years; BMI, 33.2 ± 3.6 kg/m2 (mean ± SD)) underwent a weight loss intervention consisting of a targeted 600-700 kcal/day decrease in energy intake supervised by a dietician. The length of the intervention varied between 15 and 24 weeks. Body fat mass (dual-energy X-ray absorptiometry), sleep quality (total Pittsburgh Sleep Quality Index score) and sleep duration (h/night, self-reported from the Pittsburgh Sleep Quality Index) were assessed at both baseline and at the end of the weight loss program. Results: The mean weight loss over the dietary intervention was 4.5 ± 3.9 kg, 76% of which came from fat stores. Using a multiple linear regression analysis, we observed a significant positive relationship between sleep duration and the loss of body fat, both in absolute (adjusted β = 0.72 kg/h; p < 0.05) as well as in relative terms (adjusted β = 0.77%/h; p < 0.01), after adjusting for age, sex, baseline BMI, length of the intervention, and change in total energy intake. Furthermore, we observed that a better sleep quality at baseline was associated with greater fat mass loss. Conclusion: This study provides evidence that sleeping habits can influence the success of a weight loss intervention and should be taken into consideration when one decides to start a diet. Copyright © 2012 S. Karger GmbH, Freiburg.


Gorber S.C.,Health Information and Research Division | Tremblay M.S.,Eastern Research Group | Tremblay M.S.,University of Ottawa
Obesity | Year: 2010

The objective of this study was to determine whether the bias in self-reported estimates of obesity has changed over time and followed different patterns in Canada and the United States. Using age-standardized data from three waves of the National Health and Nutrition Examination Survey (NHANES) in the United States and the Canadian Community Health Survey (CCHS) and the Canadian Heart Health Survey (CHHS) in Canada, discrepancies were compared between reported and measured estimates of height, weight, and obesity (based on the BMI) from 1976 to 2005. Results indicated that obesity increased in both countries, but rates were higher in the United States. The discrepancy between self-reported and measured obesity was small in the United States with reported data underestimating measured prevalence by about 3%; this stayed relatively constant over time. In Canada, the discrepancy was large and doubled in the past decade (from 4 to 8%). In the United States, self-reported data may be more accurate in monitoring changes in obesity over time, as the estimates have consistently remained about 3% below the measured estimates, whereas in Canada, monitoring obesity based solely on self-reported height and weight may produce inaccurate estimates because of the increasing discrepancy between self-reported and measured data. © 2009 The Obesity Society.

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