Metabolic responses to the acute ingestion of two commercially available carbonated beverages: A pilot study

<p>Abstract</p> <p>Background</p> <p>The purpose of this placebo-controlled, double-blind cross-over study was to compare the effects of two commercially available soft drinks on metabolic rate.</p> <p>Methods</p> <p>After giving informed consent, twenty healthy men and women were randomly assigned to ingest 12 ounces of Celsius™ and, on a separate day, 12 ounces of Diet Coke®. All subjects completed both trials using a randomized, counterbalanced design. Metabolic rate (via indirect calorimetry) and substrate oxidation (via respiratory exchange ratio) were measured at baseline (pre-ingestion) and at the end of each hour for 3 hours post-ingestion.</p> <p>Results</p> <p>Two-way ANOVA revealed a significant interaction (p < 0.001) between trials in metabolic rate. Scheffe post-hoc testing indicated that metabolic rate increased by 13.8% (+ 0.6 L/min, p < 0.001) 1 hr post, 14.4% (+0.63 L/min, p < 0.001) 2 hr post, and 8.5% (+0.37 L/min, p < 0.004) 3 hr post Celsius™ ingestion. In contrast, small (~4–6%) but statistically insignificant increases in metabolic rate were noted following Diet Coke^®ingestion. No differences in respiratory exchange ratio were noted between trials.</p> <p>Conclusion</p> <p>These preliminary findings indicate Celsius™ has thermogenic properties when ingested acutely. The effects of repeated, chronic ingestion of Celsius™ on body composition are unknown at this time.</p

A randomized controlled trial to evaluate self-determination theory for exercise adherence and weight control: rationale and intervention description

<p>Abstract</p> <p>Background</p> <p>Research on the motivational model proposed by Self-Determination Theory (SDT) provides theoretically sound insights into reasons why people adopt and maintain exercise and other health behaviors, and allows for a meaningful analysis of the motivational processes involved in behavioral self-regulation. Although obesity is notoriously difficult to reverse and its recidivism is high, adopting and maintaining a physically active lifestyle is arguably the most effective strategy to counteract it in the long-term. The purposes of this study are twofold: i) to describe a 3-year randomized controlled trial (RCT) aimed at testing a novel obesity treatment program based on SDT, and ii) to present the rationale behind SDT's utility in facilitating and explaining health behavior change, especially physical activity/exercise, during obesity treatment.</p> <p>Methods</p> <p>Study design, recruitment, inclusion criteria, measurements, and a detailed description of the intervention (general format, goals for the participants, intervention curriculum, and main SDT strategies) are presented. The intervention consists of a 1-year group behavioral program for overweight and moderately obese women, aged 25 to 50 (and pre-menopausal), recruited from the community at large through media advertisement. Participants in the intervention group meet weekly or bi-weekly with a multidisciplinary intervention team (30 2 h sessions in total), and go through a program covering most topics considered critical for successful weight control. These topics and especially their delivery were adapted to comply with SDT and Motivational Interviewing guidelines. Comparison group receive a general health education curriculum. After the program, all subjects are follow-up for a period of 2 years.</p> <p>Discussion</p> <p>Results from this RCT will contribute to a better understanding of how motivational characteristics, particularly those related to physical activity/exercise behavioral self-regulation, influence treatment success, while exploring the utility of Self-Determination Theory for promoting health behavior change in the context of obesity.</p> <p>Trial Registration</p> <p><b>Clinical Trials Gov. Identifier </b>NCT00513084</p

Between-Monitor Differences in Step Counts Are Related to Body Size: Implications for Objective Physical Activity Measurement

The quantification of the relationships between walking and health requires that walking is measured accurately. We correlated different measures of step accumulation to body size, overall physical activity level, and glucose regulation.Participants were 25 men and 25 women American Indians without diabetes (Age: 20-34 years) in Phoenix, Arizona, USA. We assessed steps/day during 7 days of free living, simultaneously with three different monitors (Accusplit-AX120, MTI-ActiGraph, and Dynastream-AMP). We assessed total physical activity during free-living with doubly labeled water combined with resting metabolic rate measured by expired gas indirect calorimetry. Glucose tolerance was determined during an oral glucose tolerance test.Based on observed counts in the laboratory, the AMP was the most accurate device, followed by the MTI and the AX120, respectively. The estimated energy cost of 1000 steps per day was lower in the AX120 than the MTI or AMP. The correlation between AX120-assessed steps/day and waist circumference was significantly higher than the correlation between AMP steps and waist circumference. The difference in steps per day between the AX120 and both the AMP and the MTI were significantly related to waist circumference.Between-monitor differences in step counts influence the observed relationship between walking and obesity-related traits

Design and evaluation protocol of "FATaintPHAT", a computer-tailored intervention to prevent excessive weight gain in adolescents

<p>Abstract</p> <p>Background</p> <p>Computer tailoring may be a promising technique for prevention of overweight in adolescents. However, very few well-developed, evidence-based computer-tailored interventions are available for this target group. We developed and evaluated a computer-tailored intervention for adolescents targeting energy balance-related behaviours: i.e. consumption of snacks, sugar-sweetened beverages, fruit, vegetables, and fibre, physical activity, and sedentary behaviours. This paper describes the planned development of a school-based computer-tailored intervention aimed at improving energy balance-related behaviours in order to prevent excessive weight gain in adolescents, and the protocol for evaluating this intervention.</p> <p>Methods/design</p> <p>Intervention development: Informed by the Precaution Adoption Process Model and the Theory of Planned Behaviour, the computer-tailored intervention provided feedback on personal behaviour and suggestions on how to modify it. The intervention (VETisnietVET translated as 'FATaintPHAT') has been developed for use in the first year of secondary school during eight lessons.</p> <p>Evaluation design: The intervention will be evaluated in a cluster-randomised trial including 20 schools with a 4-months and a 2-years follow-up. Outcome measures are BMI, waist circumference, energy balance-related behaviours, and potential determinants of these behaviours. Process measures are appreciation of and satisfaction with the program, exposure to the program's content, and implementation facilitators and barriers measured among students and teachers.</p> <p>Discussion</p> <p>This project resulted in a theory and evidence-based intervention that can be implemented in a school setting. A large-scale randomised controlled trial with a short and long-term follow-up will provide sound statements about the effectiveness of this computer-tailored intervention in adolescents.</p> <p>Trial Registration</p> <p>ISRCTN15743786</p

The effect of two different health messages on physical activity levels and health in sedentary overweight, middle-aged women

Background: Most public health guidelines recommend that adults need to participate in 30 minutes of moderate intensity physical activity on most days of the week to maintain good health. Achieving the recommended 30 minutes of exercise a day can be difficult in middle aged, overweight women. This 12 week study evaluated whether a 10,000 steps per day message was more effective than a 30 minutes a day message in increasing physical activity in low active, overweight women. Methods: Thirty participants were randomized into 2 groups: Group 1 was asked to undertake 30 minutes of walking/day, whereas Group 2 was asked to accumulate 10,000 steps/day using their pedometers. Results: Results showed that there were no changes in anthropometric and blood pressure measures between or within groups. However, the 10,000 step and the 30 minutes groups’ daily average number of steps/day were significantly higher than baseline at week 6 (p = 0.038 and p = 0.039 respectively) and at week 12 (p = 0.028 and p = 0.038 respectively). At week 12, the 10,000 steps group were taking an average of 4616 steps per day more (43% increase) than at baseline and the 30 minutes group were taking an average of 2761 steps per day more (35% increase) than at baseline. There was a significant difference in the number of steps with the 10,000 steps group versus 30 minutes group at 12 weeks (p = 0.045).Conclusions: This study found that low active, overweight women undertook significantly more physical activity when they had a daily 10,000 step goal using a pedometer, than when they were asked to achieve 30 minutes of walking/day. Therefore we suggest that a public health recommendation of “10,000 steps/day”, rather than the “30 min/day” could be applied to promote increased physical activity in sedentary middle aged women

Physical activity and nutrition behaviour outcomes of a cluster-randomized controlled trial for adults with metabolic syndrome in Vietnam

Background: Metabolic syndrome is prevalent among Vietnamese adults, especially those aged 50-65 years. This study evaluated the effectiveness of a 6 month community-based lifestyle intervention to increase physical activity levels and improve dietary behaviours for adults with metabolic syndrome in Vietnam. Methods: Ten communes, involving participants aged 50-65 years with metabolic syndrome, were recruited from Hanam province in northern Vietnam. The communes were randomly allocated to either the intervention (five communes, n = 214) or the control group (five communes, n = 203). Intervention group participants received a health promotion package, consisting of an information booklet, education sessions, a walking group, and a resistance band. Control group participants received one session of standard advice during the 6 month period. Data were collected at baseline and after the intervention to evaluate programme effectiveness. The International Physical Activity Questionnaire - Short Form and a modified STEPS questionnaire were used to assess physical activity and dietary behaviours, respectively, in both groups. Pedometers were worn by the intervention participants only for 7 consecutive days at baseline and post-intervention testing. To accommodate the repeated measures and the clustering of individuals within communes, multilevel mixed regression models with random effects were fitted to determine the impacts of intervention on changes in outcome variables over time and between groups. Results: With a retention rate of 80.8%, the final sample comprised 175 intervention and 162 control participants. After controlling for demographic and other confounding factors, the intervention participants showed significant increases in moderate intensity activity (P = 0.018), walking (P &lt; 0.001) and total physical activity (P = 0.001), as well as a decrease in mean sitting time (P &lt; 0.001), relative to their control counterparts. Significant improvements in dietary behaviours were also observed, particularly reductions in intake of animal internal organs (P = 0.001) and in using cooking oil for daily meal preparation (P = 0.001). Conclusions: The prescribed community-based physical activity and nutrition intervention programme successfully improved physical activity and dietary behaviours for adults with metabolic syndrome in Vietnam. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12614000811606. Registered on 31 July 201

Agreement between pedometer and accelerometer in measuring physical activity in overweight and obese pregnant women

<p>Abstract</p> <p>Background</p> <p>Inexpensive, reliable objective methods are needed to measure physical activity (PA) in large scale trials. This study compared the number of pedometer step counts with accelerometer data in pregnant women in free-living conditions to assess agreement between these measures.</p> <p>Methods</p> <p>Pregnant women (n = 58) with body mass index ≥25 kg/m²at median 13 weeks' gestation wore a GT1M Actigraph accelerometer and a Yamax Digi-Walker CW-701 pedometer for four consecutive days. The Spearman rank correlation coefficients were determined between pedometer step counts and various accelerometer measures of PA. Total agreement between accelerometer and pedometer step counts was evaluated by determining the 95% limits of agreement estimated using a regression-based method. Agreement between the monitors in categorising participants as active or inactive was assessed by determining Kappa.</p> <p>Results</p> <p>Pedometer step counts correlated moderately (r = 0.36 to 0.54) with most accelerometer measures of PA. Overall step counts recorded by the pedometer and the accelerometer were not significantly different (medians 5961 vs. 5687 steps/day, p = 0.37). However, the 95% limits of agreement ranged from -2690 to 2656 steps/day for the mean step count value (6026 steps/day) and changed substantially over the range of values. Agreement between the monitors in categorising participants to active and inactive varied from moderate to good depending on the criteria adopted.</p> <p>Conclusions</p> <p>Despite statistically significant correlations and similar median step counts, the overall agreement between pedometer and accelerometer step counts was poor and varied with activity level. Pedometer and accelerometer steps cannot be used interchangeably in overweight and obese pregnant women.</p

Secular trends: a ten-year comparison of the amount and type of physical activity and inactivity of random samples of adolescents in the Czech Republic

BACKGROUND: An optimal level of physical activity (PA) in adolescence influences the level of PA in adulthood. Although PA declines with age have been demonstrated repeatedly, few studies have been carried out on secular trends. The present study assessed levels, types and secular trends of PA and sedentary behaviour of a sample of adolescents in the Czech Republic. METHODS: The study comprised two cross-sectional cohorts of adolescents ten years apart. The analysis compared data collected through a week-long monitoring of adolescents' PA in 1998-2000 and 2008-2010. Adolescents wore either Yamax SW-701 or Omron HJ-105 pedometer continuously for 7 days (at least 10 hours per day) excluding sleeping, hygiene and bathing. They also recorded their number of steps per day, the type and duration of PA and sedentary behaviour (in minutes) on record sheets. In total, 902 adolescents (410 boys; 492 girls) aged 14-18 were eligible for analysis. RESULTS: Overweight and obesity in Czech adolescents participating in this study increased from 5.5% (older cohort, 1998-2000) to 10.4% (younger cohort, 2008-2010). There were no inter-cohort significant changes in the total amount of sedentary behaviour in boys. However in girls, on weekdays, there was a significant increase in the total duration of sedentary behaviour of the younger cohort (2008-2010) compared with the older one (1998-2000). Studying and screen time (television and computer) were among the main sedentary behaviours in Czech adolescents. The types of sedentary behaviour also changed: watching TV (1998-2000) was replaced by time spent on computers (2008-2010).The Czech health-related criterion (achieving 11,000 steps per day) decreased only in boys from 68% (1998-2000) to 55% (2008-2010). Across both genders, 55%-75% of Czech adolescents met the health-related criterion of recommended steps per day, however less participants in the younger cohort (2008-2010) met this criterion than in the older cohort (1998-2000) ten years ago. Adolescents' PA levels for the monitored periods of 1998-2000 and 2008-2010 suggest a secular decrease in the weekly number of steps achieved by adolescent boys and girls. CONCLUSION: In the younger cohort (2008-2010), every tenth adolescent was either overweight or obese; roughly twice the rate when compared to the older cohort (1998-2000). Sedentary behaviour seems relatively stable across the two cohorts as the increased time that the younger cohort (2008-2010) spent on computers is compensated with an equally decreased time spent watching TV or studying. Across both cohorts about half to three quarters of the adolescents met the health-related criterion for achieved number of steps. The findings show a secular decrease in PA amongst adolescents. The significant interaction effects (cohort × age; and cohort × gender) that this study found suggested that secular trends in PA differ by age and gender