
Sarah PurcellUniversity of British Columbia - Okanagan | UBC Okanagan
Sarah Purcell
Doctor of Philosophy
About
40
Publications
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Introduction
My research builds upon key concepts of nutrition, energy balance regulation, and body composition to: 1) Characterize energy intake requirements and the determinants of such, and 2) Assess how perturbations in energy balance impact other physiological and behavioral outcomes. The ultimate goal of this research is to help fill critical knowledge gaps regarding optimal strategies to manage obesity and disease-specific health outcomes through evidence-based nutrition strategies.
Publications
Publications (40)
Purpose:
Metabolic diseases such as diabetes mellitus may play a role in the development and progression of prostate cancer (PC); however, this association remains to be explored in the context of specific PC stages. The objective of this study was to systematically review the evidence for an association between diabetes and overall, early, or adv...
We tested whether spontaneous physical activity (SPA) from accelerometers could be used in a whole-room calorimeter to estimate thermic effect of food (TEF). Eleven healthy participants (63% female; age: 27 ± 4 years; body mass index: 22.8 ± 2.6 kg/m ² ) completed two 23-hour visits in randomized order: one 'fed' with meals provided and one 'fasted...
Background:
Total energy expenditure (TEE) determines energy requirements, but objective data in patients with cancer is limited.
Objective:
We aimed to characterize TEE, investigate its predictors, and compare TEE with cancer-specific predicted energy requirements.
Design:
This cross-sectional analysis included patients with stage II-IV color...
Energy balance accounts for an individual's energy intake, expenditure, and storage. Each aspect of energy balance has implications for the pharmacokinetics of cancer treatments and may impact an individual's drug exposure and subsequently its tolerance and efficacy. However, the integrated effects of diet, physical activity, and body composition o...
Introduction/purpose:
A reduction in nonexercise physical activity (NEPA) after exercise may reduce the effectiveness of exercise interventions on weight loss in adults with overweight or obesity. Aerobic exercise (AEx) and resistance exercise (REx) may have different effects on NEPA. The purpose of this secondary analysis was to examine the effec...
Purpose: This study compared anthropometric and body fat percent (BF%) equations in relation to measures of metabolic health.
Methods: BF% calculations (Bergman, Fels, and Woolcott) and anthropometric measurements were used to determine obesity among a sample of patients attending primary care in Alberta, Canada. Anthropometric variables included b...
Appetite is a determinant of dietary intake and is impacted by sex hormones, exercise, and body composition among individuals without chronic conditions. Whether appetite is altered by exercise in the context of estrogen suppression and cancer survivorship is unknown. This randomized cross-over study compared appetite and ad libitum energy intake (...
Introduction/purpose:
Dietary restriction (DIET) and aerobic exercise (AEX) interventions may impact energy balance differently. Our aim was to describe the effects of weight loss interventions via DIET or AEX on measures of energy balance.
Methods:
Adults with overweight or obesity were randomized to 12 weeks of DIET or AEX with similar calorie...
Individuals with cancer may be motivated to make lifestyle changes and inform dietary choices yet are exposed to conflicting and erroneous nutritional information, particularly from online and social media sources. Changes to dietary choices that stem from a diagnosis of cancer are not fully understood. Thus, we conducted a narrative review to summ...
Body composition parameters are not captured by measures of body mass, which may explain inconsistent associations between body weight and prostate cancer (PC) risk. The objective of this systematic review was to characterize the association between fat mass (FM) and fat-free mass (FFM) parameters and PC risk. A search of PubMed, Embase, and Web of...
The purpose of this study was to evaluate the feasibility and acceptability of randomizing adults with overweight and obesity (BMI 25–40 kg/m2) to morning (06:00–10:00) or evening (15:00–19:00) aerobic exercise. Participants completed four exercise sessions per week in the morning (AM, n = 18) or evening (PM, n = 15). The exercise program was 15 we...
Many breast cancer survivors (BCS) gain fat mass and lose fat-free mass during treatment (chemotherapy, radiation, surgery) and estrogen suppression therapy, which increases the risk of developing comorbidities. Whether these body composition alterations are a result of changes in dietary intake, energy expenditure, or both is unclear. Thus, we rev...
Yoga may reduce body weight in individuals with overweight or obesity, but whether this occurs through decreased energy intake (EI) or increased energy expenditure (EE)/physical activity (PA) is unclear. A systematic search of PubMed, Web of Science, Embase, and PsychINFO was conducted from inception until April 26, 2021. Eligible studies included...
Sarcopenic obesity is associated with several negative health outcomes. However, the prevalence of this condition – and the relationship to physical performance parameters – varies across definitions. The aim of this cross-sectional investigation was to describe the prevalence of sarcopenic obesity using different published definitions and their re...
Background and aims
The accuracy of some portable indirect calorimeters in estimating resting energy expenditure (REE) - and hence energy recommendations - among pre-bariatric patients is unknown. Our objective was to assess the accuracy of the MedGem® among individuals with class II or III obesity awaiting bariatric surgery.
Methods
Male and fema...
Background/objectives
Resting energy expenditure (REE) is the largest component of total energy expenditure. As such, inaccurate estimation or measurement of REE may impact the development of individualized energy intake recommendations. The objective of this observational study was to assess the accuracy and reliability of REE measured with a port...
Objectives
Sarcopenia is a debilitating condition affecting millions of individuals worldwide and is defined with different criteria. The objective of this study was to determine the prevalence of sarcopenia in older Canadians using three internationally accepted criteria.DesignObservational cohort study.Settings and participantsData from 12,592 su...
Many patients with cancer experience poor nutritional status, which detrimentally impacts clinical outcomes. Poor nutritional status in cancer is primarily manifested by severe muscle mass (MM) depletion, which may occur at any stage (from curative to palliative) and often co‐exists with obesity. The objective of this article was to discuss gaps an...
Background:
Our purpose was to assess the accuracy of resting energy expenditure (REE) equations in patients with newly diagnosed stage I-IV non-small cell lung, rectal, colon, renal, or pancreatic cancer.
Methods:
In this cross-sectional study, REE was measured using indirect calorimetry and compared with 23 equations. Agreement between measure...
Background: Understanding resting energy expenditure (REE) is important for determining energy requirements; REE might be altered in individuals with cancer. The objective of this study was to characterize determinants of REE in patients with stages II–IV colorectal cancer (CRC).
Methods: REE was measured via indirect calorimetry in patients with n...
Background:
Total energy expenditure (TEE) data in patients with early-stage cancer are scarce, precluding an understanding of energy requirements.
Objective:
The objective was to cross-sectionally characterize TEE in patients with colorectal cancer (CRC) and to compare measured TEE with energy recommendations. It was hypothesized that TEE would...
Background & aims:
Resting energy expenditure (REE) is variable in cancer and might be influenced by changes in tumor burden, systemic inflammation, and body composition. The objective of this study was to assess REE change and the predictors of such in patients with stage III or IV colorectal cancer.
Methods:
REE was measured via indirect calor...
Background:
Accurate assessment of energy expenditure may support weight-management recommendations. Measuring energy expenditure for each postpartum woman is unfeasible; therefore, accurate predictive equations are needed.
Objectives:
This study compared measured with predicted resting energy expenditure (REE) and total energy expenditure (TEE)...
Purpose of Review
Body weight and body composition (i.e., skeletal muscle and adipose tissue) are indicators of long-term energy balance and substrate metabolism. The objective of the current review was to describe the role of energy balance on survival and the potential mechanisms of this relationship in patients with colorectal cancer (CRC).
Rec...
Abnormalities in body composition can occur at any body weight. Low muscle mass is a predictor of poor morbidity and mortality and occurs in several populations. This narrative review provides an overview of the importance of low muscle mass on health outcomes for patients in inpatient, outpatient and long-term care clinical settings. A one-year gl...
Background
Determining optimal caloric intake for an individual with cancer is complicated by metabolic changes that occur, namely, alterations in resting energy expenditure (REE). There is currently no validated clinically available equation or tool to measure energy expenditure in these patients.
Methods
Patients with newly diagnosed solid tumor...
Aim:
To investigate the prevalence of sarcopenic obesity (SO) and its association with health outcomes in patients seeking weight loss treatment from a bariatric center.
Methods:
In this retrospective study, patients [≥18 years old, body mass index (BMI) ≥30 kg/m2] from the Tallahassee Memorial Bariatric Center and with baseline body composition...
Background & aim
Low fat free mass (FFM) or high fat mass (FM) are abnormal body composition phenotypes associated with morbidity. These conditions in combination lead to worse health outcomes, and can be identified by a high FM/FFM ratio. Here, we developed sex, age, and body mass index (BMI) stratified, population-based FM/FFM reference values us...
Great discrepancies exist in the reported prevalence of altered energy metabolism (hypo- or hypermetabolism) in cancer patients, which is likely due to the vast array of phenomena that can affect energy expenditure in these patients. The purpose of this review was to critically evaluate key determinants of energy expenditure in cancer and the relev...
Measures of body weight and anthropometrics such as body mass index (BMI) are commonly used to assess nutritional status in clinical conditions including cancer. Extensive research has evaluated associations between body weight and prognosis in ovarian cancer patients, yet little is known about the potential impact of body composition (fat mass (FM...
Purpose:
To describe body composition (fat mass (FM) and fat-free mass (FFM)), strength, and nutritional characteristics of patients with hip or knee osteoarthritis undergoing total joint arthroplasty.
Methods:
In this prospective pilot study, osteoarthritic patients underwent body composition assessment using bioelectrical impedance analysis, g...
Poster and oral presentations assessing resting energy expenditure and body composition in a sample of 46 individuals with advanced lung or colorectal cancer.
Osteopenia/osteoporosis, sarcopenia, and obesity are commonly observed in the process of aging, and recent evidence suggests a potential interconnection of these syndromes with common pathophysiology. The term osteosarcopenic obesity has been coined to describe the concurrent appearance of obesity in individuals with low bone and muscle mass. Altho...