The atypical antipsychotic risperidone is associated with weight gain and cardio-metabolic side effects. In light of growing evidence implicating the gut microbiome in the host’s energy regulation and in xenobiotic metabolism, it is hypothesized that risperidone-induced weight gain is mediated through alterations in the gut microbiome. The impact of chronic and short-term risperidone treatment on the gut microbiome of pediatric, psychiatric patients was examined in a cross-sectional and prospective design. Chronic treatment with risperidone was associated with a significant increase in body mass index (BMI) and a significant reduction in the ratio of Bacteroidetes to Firmicutes, as compared to naïve psychiatric controls. Predictive metagenomic analyses, indicate that gut microbiota dominating the risperidone-treated patients are enriched for pathways, such as short-chain fatty acid production, which have been implicated in weight gain. Alterations in the microbiome due to risperidone treatment were further demonstrated in wild-type female mice and shown to be a result of a reduction in host energy expenditure. Risperidone-treated mice exhibit significant weight gain and an altered gut microbiome relative to controls while maintaining normal food intake behavior and digestive efficiency, indicating that increased weight gain is due to reduced energy expenditure. Moreover, fecal transfer from risperidone-treated mice to a second cohort of naïve mice was performed via daily gastric gavage and aerobic and non-aerobic resting metabolic rates (RMR) were monitored using combined calorimetry. This transfer has no effect on aerobic RMR in recipients, but induces a significant suppression of non-aerobic RMR in mice receiving stool from risperidone-treated donors establishing a causal effect of the altered gut microbiome upon energy expenditure. Finally, daily transfer of phage, a subset of the gut microbiome, isolated from the gut of risperidone treated donors was also sufficient to cause excess weight gain in naïve recipients animals through suppression of energy expenditure. Together, these data highlight a major role for the gut microbiome for weight gain following chronic use of risperidone, and demonstrate that the mechanism depends upon suppression of energy expenditure.

It is well understood that substantial health inequality exists for adults with an intellectual disability (AWID). In comparison to the general population AWID experience higher rates of morbidity and mortality associated with sedentary lifestyles, yet little is known about the role physical activity plays in preventing or mediating this outcome for this segment of society. Without appropriate instrumentation, it is not possible to address the inadequacies that currently exist in the area of physical activity and AWID. The primary aim of the series of studies in this thesis was to develop a psychometrically sound proxy-respondent measurement tool that could be used by researchers, epidemiologists and public health personnel to gather information on the physical activity behaviours of AWID. The International Physical Activity Questionnaire (IPAQ) is an internationally published tool with good psychometric properties when used as a self-report tool with adults without a disability (AWOID), but no evidence exists as to the validity or reliability of this tool when used by proxy respondents to report on the physical activity behaviour of AWID. Given little is known about the energy expenditure characteristics of AWID, nor the accuracy of tools developed for AWOID when applied to AWID, two secondary aims of this thesis were to measure the energy expended by AWID and AWOID during seven common activities of daily living (ADL) and to assess the accuracy of an objective physical activity measurement tool (Caltrac® accelerometer) for use with AWID. Evidence gathered through the studies in this thesis found that as the energy demand of ADL increased there was an increase in the difference between energy expended by AWID and AWOID. Results indicated that AWID achieved moderate-intensity physical activity when walking at a pace of 3.0 km/hr or more. The proxy-respondent telephone questionnaire (IPAQ-ID) described in this thesis allows for universal assessment of the physical activity behaviours of AWID. The IPAQ-ID was found to have measurement properties equivalent to measurement tools used among AWOID. The IPAQ-ID was found to be suitable for use as a surveillance tool by researchers to collect comparable data on health-enhancing physical activity behaviours of AWID.

Thesis (M.A. (Human Movement Science))--North-West University, Potchefstroom Campus, 2009.

Purpose. To investigate the validity of the Sense Wear Pro Armband (SWA) to measure energy expenditure (EE) in healthy participants using wheelchair ergometry as an exercise modality. Method. Minute by minute EE was measured simultaneously using the SWA and indirect calorimetry(IC) during three different wheeling speeds including self-selected speed (0.81 m/s), moderate speed (1.11 m/s), and fast speed (1.73 m/s). Results. Twenty healthy volunteers (age = 34.0 (5.8) years)participated. The intraclass correlation coefficients (ICCs) were 0.50 (p=0.010), 0.59 (p=0.003), and 0.68 (p=0.000) for the self-selected speed, moderate speed, and fast speed wheeling, respectively. The SWA overestimated EE 57.8%, 57.4 %, and 63.7% for self-selected speed, moderate speed, and fast speed, respectively. Conclusions. The SWA failed to provide an accurate estimate of EE as measured by indirect calorimetry for wheelchair ergometry exercise in healthy subjects. The SWA overestimated EE for all exercise intensities. / REHABILITATION SCIENCE-PHYSICAL THERAPY

This dissertation was designed to determine the effects of body mass index (BMI) and walking speed on activity monitor outputs. A secondary purpose was to compare the activity monitors’ performance in a free-living environment. In the first experiment, 71 participants wore three waist-mounted activity monitors (Actical, ActiGraph, and NL-2000) and an ankle-mounted device (StepWatch 3) while walking on a treadmill (40, 67 and 94 m/min). The tilt angle of each device was measured. The Actical recorded 26% higher activity counts (P < 0.01) in obese persons with a tilt <10 degrees, compared to normal weight persons. The ActiGraph was unaffected by BMI or tilt angle. In the second experiment, the steps recorded by the devices were compared to actual steps. Speed had the greatest influence on the accuracy these devices. At 40 m/min, the ActiGraph was the least accurate device for normal weight (38%), overweight (46%) and obese (48%) individuals. The Actical, NL-2000 and StepWatch averaged 65%, 73% and 99% of steps taken, respectively. Lastly, several generations of the ActiGraph (7164, GT1M, and GT3X), and other research grade activity monitors (Actical; ActivPAL; and Digi-Walker) were compared to a criterion measure of steps. Fifty-six participants performed treadmill walking (40, 54, 67, 80 and 94 m/min) and wore the devices for 24-hours under free-living conditions. BMI did not affect step count accuracy during treadmill walking. The StepWatch, PAL, and the AG7164 were the most accurate across all speeds; the other devices were only accurate at the faster speeds. In the free-living environment, all devices recorded about 75% of StepWatch-determined steps, except the AG7164 (99%). Based on these findings, we conclude that BMI does not affect the output of these activity monitors. However, waist-borne activity monitors are highly susceptible to under-counting steps at walking speeds below 67 m/min, or stepping rates below 100 steps/min. An activity monitor worn on the ankle is less susceptible to these speed effects and provides the greatest accuracy for step counting.

Social support has been recognized to impact positive health behaviours, including exercise participation. In the exercise domain, one conceptual framework that has been employed to examine social support is Weisss (1974) Model of Social Provisions. The main purpose of the present study was to utilize Weisss (1974) model to examine how the social provisions relate to university students energy expenditure while exercising with others. Specifically, this study was concerned with participants perceptions about the availability of social provisions, their preferences for the provisions in the exercise setting, and the congruence between social provision perceptions and preferences as they related to energy expenditure. Participants who had performed exercise with others in the past 4 weeks (N=201) completed the Modifiable Activity Questionnaire (MAQ; Kriska et al., 1990) to assess energy expenditure, as well as modified versions of the Social Provisions Scale (Cutrona & Russell, 1987) to assess social provision perceptions and preferences. Results from exploratory factor analyses revealed separate five-factor models for both the perceived provisions (i.e., attachment, reliable alliance, social integration, opportunity for nurturance, and reassurance of worth) and the preferred provisions (i.e., guidance, social integration, reliable alliance, reassurance of worth, and opportunity for nurturance). Discriminant function analyses were used to assess the unique contribution of these perceived and preferred provisions to participants energy expenditure. The results from the analyses indicated that none of the perceived provisions and none of the preferred provisions predicted high versus low expenditure, nor did the congruence relationship between the perceived and preferred variants of each provision predict high versus low energy expenditure. Potential explanations for the non-significant findings were highlighted with respect to study methodology. Directions for future research were also discussed.

Social support has been recognized to impact positive health behaviours, including exercise participation. In the exercise domain, one conceptual framework that has been employed to examine social support is Weisss (1974) Model of Social Provisions. The main purpose of the present study was to utilize Weisss (1974) model to examine how the social provisions relate to university students energy expenditure while exercising with others. Specifically, this study was concerned with participants perceptions about the availability of social provisions, their preferences for the provisions in the exercise setting, and the congruence between social provision perceptions and preferences as they related to energy expenditure. Participants who had performed exercise with others in the past 4 weeks (N=201) completed the Modifiable Activity Questionnaire (MAQ; Kriska et al., 1990) to assess energy expenditure, as well as modified versions of the Social Provisions Scale (Cutrona & Russell, 1987) to assess social provision perceptions and preferences. Results from exploratory factor analyses revealed separate five-factor models for both the perceived provisions (i.e., attachment, reliable alliance, social integration, opportunity for nurturance, and reassurance of worth) and the preferred provisions (i.e., guidance, social integration, reliable alliance, reassurance of worth, and opportunity for nurturance). Discriminant function analyses were used to assess the unique contribution of these perceived and preferred provisions to participants energy expenditure. The results from the analyses indicated that none of the perceived provisions and none of the preferred provisions predicted high versus low expenditure, nor did the congruence relationship between the perceived and preferred variants of each provision predict high versus low energy expenditure. Potential explanations for the non-significant findings were highlighted with respect to study methodology. Directions for future research were also discussed.

Adolescence is a life history transition of individual and evolutionary importance: the body begins to allocate energy available above maintenance costs away from somatic growth and towards reproductive function. This study investigates how both distal, intergenerational effects and proximal, seasonal changes in energy availability impact the way adolescent female bodies allocate energy among linear growth, fat and lean mass, activity, and metabolic function. The research follows up on a prenatal supplementation study conducted by the British Medical Research Council in rural Gambia between 1989 and 1994. Pregnant women were randomized to receive daily supplements of 1015 kcal either from week 20 of pregnancy until delivery or during the first 20 weeks of lactation. The 67 adolescent daughters included in the follow up study were born to women in both groups during the rainy agricultural season, the period of the year associated with weight loss, poor perinatal outcomes, and high impact of the pregnancy supplement on birth weight. Anthropometry, body composition, daily saliva, weekly serum, and weekly fasting urine samples for C-peptide of insulin were collected during one month each in the 2009 rainy agricultural season, the 2010 dry harvest season, and the 2010 rainy agricultural season. Participant heart rates were calibrated to oxygen consumption each season, and 24-hr accelerometer and heart rate data were recorded to estimate free-living energy expenditure. It was found that pregnancy supplementation status did not predict infant or adolescent phenotype in the study sample. Maternal postpartum weight, however, was a powerful positive distal predictor of adolescent size. The daughters of heavier mothers produced less leptin per unit fat mass. Under conditions of high energy expenditure and low intake, adolescent women who were growing in height mobilized adipose stores and acquired lean mass, while developmentally older women maintained fat stores at the expense of lean mass. Married adolescents in the sample were older, had lower fasting C-peptide of insulin, had higher absolute energy expenditure, and spent more of their total energy budgets in activity than did unmarried peers. / Human Evolutionary Biology

Revised; Originally published: 10/2008 / 3 pp. / Recently, a number of global positioning system (GPS) devices have been introduced commercially which exploit GPS, transforming frequent measurements of time and location, into an estimate of energy expenditure. This fact sheet reviews how GPS watches (GPS fitness units) measure energy expenditure of individual during physical activity. We list popular GPS watches that are on the market and show pros and cons of these watches. After our field testing, we decided that the Garmin Forerunner 305 is our best pick for the GPS watch. We included information on geocaching, which is one of several popular outdoor activities using a GPS receiver or other navigational techniques.

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