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478
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Introduction
Lecturer
Additional affiliations
August 2018 - June 2021
January 2018 - July 2018
Education
January 2014 - December 2017
Publications
Publications (47)
A systematic review and meta-analysis was performed to determine the effect of exercise training on fasting gastrointestinal appetite hormones in adults living with overweight and obesity. For eligibility, only randomised controlled trials (duration ≥ four weeks) examining the effect of exercise training interventions were considered. This review w...
BACKGROUND: Differences in weight loss between isocaloric high-carbohydrate and high-fat diets are generally small; however, weight loss responses vary within diet groups. Genotype patterns may modify the effects of diets, but findings are equivocal. We investigated whether weight loss on a diet concordant with one’s presumed genotype (fat-responsi...
The ACSM metabolic equations have been used to estimate energy expenditure (EE) during exercise; yet limited evidence supports their accuracy in overweight/obese and sedentary individuals, especially during aerobic exercise training.
PURPOSE: Evaluate the relationship between measured and estimated EE over a 24-wk exercise intervention and determi...
BACKGROUND:
Intensive lifestyle interventions (ILIs) stimulate weight loss in underserved patients with obesity, but the mediators of weight change are unknown.
OBJECTIVES:
Identify the mediators of weight change during an ILI versus usual care (UC) in underserved patients with obesity.
DESIGN:
The Promoting Successful Weight Loss in Primary Car...
Objectives
We developed the PortionSizeTM app (PS) to estimate food intake and dietary adherence based on images of meals captured before and after eating occurs. The PS app provides real-time feedback to users about their dietary intake (energy, nutrients, and food groups) and adherence to specific diets. This pilot study provided initial tests of...
Background
The physiological benefits associated with corporately sponsored weight loss programs are increasingly well documented. However, less is known about how these programs affect employees’ quality of life (QoL). The purpose of the present analysis was to examine the association between weight loss, change in physical activity, and change in...
BACKGROUND: The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE™) phase 2 trial tested the effects of two years of 25% calorie restriction (CR) on aging in humans. CALERIE 2 was one of the first studies to use a graph of predicted weight loss to: 1) provide a proxy of dietary adherence, and 2) promote dietary adh...
Background
For many cardiovascular risk factors there is no lower limit to which further reduction will result in decreased disease risk; this includes values within ranges considered normal for healthy adults. This seems to be true for new emerging metabolic risk factors identified by innovative technological advances. Further, there seems to be e...
The physiological and metabolic effects of experimental overfeeding have been extensively studied, yet only few studies have assessed overfeeding effects on eating behaviors and psychological constructs. We analyzed two 8-week overfeeding studies, the PROOF Study (N = 25; 16 males; 16 African American; 24.1 years; 25.1 kg/m², inpatient) and the EAT...
BACKGROUND: Exercise training induces weight compensation (i.e., less weight loss than expected), yet compensatory responses are varied. This analysis tested whether baseline eating attitudes and behaviors predict compensation and energy intake changes during aerobic exercise training.
METHODS: Adults with overweight or obesity were randomized for...
We conducted an online survey to examine the preference, expected burden, and willingness of people to use four different methods of assessing food and alcohol intake such as food/drink record, 24-h recall, Remote Food Photography Method© (RFPM, via SmartIntake® app), and a novel app (PortionSize®) that allows the in-app portion size estimation of...
Caloric restriction (CR) improves markers of aging in humans, but it is not known if the fat mass and obesity-associated gene (FTO) rs9939609 single nucleotide polymorphism (SNP), which is associated with increased appetite and energy intake, influences adherence to prolonged CR. Utilizing data from the two-year Comprehensive Assessment of Long-ter...
INTRODUCTION:
Our primary aim was to investigate the association between initial weight change and longer-term changes in weight and compensation (predicted weight loss - observed weight loss) during exercise. As secondary aims, we investigated if initial weight change was related to change in cardiometabolic risk markers and energy balance modula...
While limited evidence suggests that longer sleep durations can improve metabolic health in habitual short sleepers, there is no consensus on how sustained sleep extension can be achieved. A total of 18 men (mean [SD] age 41 [ 9] years), who were overweight/obese (mean [SD] body mass index 30 [3] kg/m2) and short sleepers at increased risk of type...
Background
Foods that increase obesity risk are ubiquitous in the US food environment. Such foods may be the target of hedonic eating, which may facilitate weight gain and lead to obesity.
The study tested whether meal composition during an ad libitum buffet meal was associated with 1-year weight and percent body fat changes among healthy younger a...
Many adults receive inadequate sleep, which elevates obesity and type 2 diabetes risk and may hinder benefits of calorie restriction (CR). We hypothesized that short sleepers would experience less weight loss and diminished glycemic benefits compared to adequate sleepers during CR.
We performed secondary analyses in participants randomized to 25% C...
Purpose:
Calorie restriction (CR) is an effective treatment for obesity-related liver and metabolic disease. However, CR studies in individuals without obesity are needed to see if CR could delay disease onset. Liver biomarkers indicate hepatic health and are linked to cardiometabolic disease. Our aim was to examine the effects of a 2-year CR inte...
BACKGROUND: Intensive lifestyle interventions (ILIs) are the first-line approach to effectively treat obesity and manage associated cardiometabolic risk factors. Because few people have access to ILIs in academic health centers, primary care must implement similar approaches for a meaningful effect on obesity and cardiometabolic disease prevalence....
Office-based activity reduces sedentariness, yet no randomized controlled trials (RCTs) have assessed how such activity influences visceral adipose tissue (VAT). This study examined the effect of an office-based, multicomponent activity intervention on VAT. The WorkACTIVE-P RCT enrolled sedentary office workers (body mass index: 31.4 (standard devi...
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is linked to obesity and dyslipidemia, yet the independent influence of this polymorphism on blood lipids remains equivocal. We examined the influence of the FTO rs9939609 polymorphism on fasting and postprandial blood lipids in individuals homozygous for the risk A-allele or T-allel...
INTRODUCTION: Caloric restriction (CR) improves cardiometabolic risk, even among individuals without obesity. However, it is unclear whether these aging-related benefits are mediated by weight loss. Mediation analyses inform mechanisms underlying relationships between an exposure and outcome. Using mediation analyses, our aim was to test if 2-year...
Many psychological, behavioral, and quality of life (QOL)-related factors have been shown to be associated with higher body weight and body mass index (BMI). However, evidence for QOL as an obesity treatment predictor is to date equivocal due to conflicting results. We aimed to assess the association between QOL and BMI at baseline and also between...
Caloric restriction (CR) is a strategy that attenuates aging in multiple nonhuman species. The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) trials are part of a research program aiming to test the effects of CR on aging and longevity biomarkers in humans. Building on CALERIE phase 1, CALERIE phase 2 (CALERIE...
INTRODUCTION: Physical activity (PA) is linked to better weight control and eating behaviors in the general population, but these associations may be altered in a racially and socioeconomically diverse sample at risk for metabolic disease. We examined how PA levels are related to markers of adiposity and eating behaviors in a diverse sample of indi...
The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE) study showed that individuals who are nonobese were able to undergo significant calorie restriction (CR), yet the time course changes in adherence, weight, and appetite are unknown. This analysis aimed to investigate the time course changes in adherence...
OBJECTIVE:
This study aimed to determine whether different measures of habitual physical activity (PA) at baseline predict weight change, weight compensation, and changes in energy intake (EI) during a 24-week supervised aerobic exercise intervention.
METHODS:
Data from 108 participants (78 women; 48.7 [SD: 11.6] years; BMI 31.4 [SD: 4.6] kg/m2...
BACKGROUND: Exercise is recommended for weight management; however, exercise-induced weight loss often is less than expected based on measured energy expenditure. This discrepancy is called weight compensation and results primarily from exercise-induced increases in energy intake. It is unknown if factors pertaining to one’s lifestyle prior to star...
Calorie restriction (CR) is a potent modulator of longevity in multiple species. A growing body of evidence shows that sustained periods of CR without malnutrition improves risk factors involved in the pathophysiology of type 2 diabetes, cardiovascular diseases, cancer, and neurological disorders in humans. Innovative dietary strategies such as int...
BACKGROUND: Obesity, particularly when combined with the metabolic syndrome (MetS), is associated with reduced quality of life (QOL). Underserved and minority populations suffer from a disproportionately high prevalence of obesity and related comorbidities. However, due to low health literacy, underserved individuals may be unaware of obesity-relat...
BACKGROUND: Fatigue is broadly defined as a perceived lack of energy that interferes with general functioning and disrupts usual routines. Fatigue has been linked with obesity in the general population, yet it is not known if this relationship holds in an underserved cohort. Additionally, the potential mechanisms underlying this relationship are no...
PURPOSE:
Heart rate recovery (HRR) after exercise is an independent risk factor for cardiovascular disease and mortality. Regular aerobic exercise can improve HRR, yet little is known regarding the dose necessary to promote increases. The aim was to assess the impact of different doses of vigorous-intensity aerobic exercise on HRR in individuals w...
African Americans (AAs) have a higher obesity risk than Whites; however, it is unclear if appetite-related hormones and food intake are implicated. We examined differences in appetite-related hormones, appetite, and food intake between AAs (n = 53) and Whites (n = 111) with overweight or obesity. Participants were randomized into a control group or...
Background:
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is associated with higher acyl-ghrelin (AG) concentrations, higher energy intake, and obesity, although exercise may mitigate rs9939609 A-allele-linked obesity risk. Butyrylcholinesterase (BChE) hydrolyzes AG to des-acyl-ghrelin (DAG), potentially decreasing appetite. Ho...
Calorie restriction (CR) enhances longevity in humans who are normal weight, overweight and obese. While dietary regimens can change self-efficacy, eating behaviors, and food cravings in individuals with obesity, the responses of these measures to prolonged CR in individuals who are exclusively not obese is unknown. The aim of this analysis was to...
Background:
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele has been associated with obesity risk. Although the exact mechanisms involved remain unknown, the FTO rs9939609 A-allele has been associated with an impaired postprandial suppression of appetite.
Objectives:
To explore the influence of FTO rs9939609 genotype on fasting...
Background: After meal ingestion, a series of coordinated hormone responses occur concomitantly with changes in perceived appetite. It is not known whether interindividual variability in appetite exists in response to a meal. Objectives: This study aimed to 1) assess the reproducibility of appetite responses to a meal; 2) quantify individual differ...
Exercise facilitates weight control, partly through effects on appetite regulation. Single bouts of exercise induce a short-term energy deficit without stimulating compensatory effects on appetite, whilst limited evidence suggests that exercise training may modify subjective and homeostatic mediators of appetite in directions associated with enhanc...
Exercise facilitates weight control, partly through effects on appetite regulation. Single bouts of exercise induce a short-term energy deficit without stimulating compensatory effects on appetite, whilst limited evidence suggests that exercise training may modify subjective and homeostatic mediators of appetite in directions associated with enhanc...
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Purpose: This study examined the feasibility of sprint interval exercise training (SIT) for men with non-alcoholic fatty liver disease (NAFLD) and its effects on intrahepatic triglyceride (IHTG), insulin sensitivity (hepatic and peripheral), visceral (VAT) and subcutaneous adipose tissue (ScAT).
Methods: Nine men with NAFLD (age 41±8 years; BMI 31....
Single nucleotide polymorphisms (SNPs) in the fat mass and obesity-associated ( FTO ) locus are associated with obesity, but lifestyle factors may modulate the obesity risk related to FTO . This study examined the physical activity and dietary patterns of 528 physically active white men and women (mean (SD): 34.9 (9.5) years, 26.6 (4.3) kg·m ⁻² ) c...
Supplementary Methods: ethnicity information collection. Supplementary Table 1: obesity-related parameters in men and women carrying different risk variants of the FTO rs9939609 single nucleotide polymorphism. Supplementary Table 2: physical activity levels in men and women carrying different risk variants of the FTO rs9939609 single nucleotide pol...
Purpose:
Acute exercise transiently suppresses appetite, which coincides with alterations in appetite-regulatory hormone concentrations. Individual variability in these responses is suspected, but replicated trials are needed to quantify them robustly. We examined the reproducibility of appetite and appetite-regulatory hormone responses to acute e...
Introduction:
Sprint interval training (SIT) is a novel form of exercise (high intensity, short duration) which improves IS in healthy, overweight adults despite a total exercise volume much lower than current guidelines. This study investigated the effects of SIT on hepatic and peripheral IS, and IHTG, in men with NAFLD.
Methods:
9 overweight/obe...
Objective
To examine physical activity and dietary patterns in physically active individuals carrying different risk variants of the fat mass and obesity-associated gene ( FTO ) rs9939609 single nucleotide polymorphism (SNP).
Methods
A total of 528 white men and women (mean (SD): 34.9(9.5) years, 26.6(4.3) kg·m ⁻² ) were genotyped for FTO rs993960...
Research suggests that carbohydrate mouth rinsing (CMR) improves endurance performance; yet, little is known regarding the effect of CMR on multiple sprint efforts. As many sports involve multiple sprinting efforts, followed by periods of recovery, the aim of our current study was to investigate the influence of CMR on multiple sprint performance....
Projects
Projects (3)
The Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) Phase 2 trial was a 2-year, parallel-group,
randomized control trial that was conducted at three clinical sites: Pennington Biomedical Research Center, Washington University School of Medicine, and Tufts University.
Participants were randomly enrolled in either a calorie restriction (CR) group or an ad libitum (AL) control group. The CR group participated in an intensive behavioral intervention that aimed to decrease energy intake by 25%, while the AL group was instructed to maintain habitual
energy intake.
The PROmoting Successful Weight Loss in Primary CarE in Louisiana (PROPEL) trial was a cluster-randomized trial testing the effectiveness of a high-intensity, lifestyle-based program for obesity treatment delivered in primary care clinics in which a high percentage of the patients were from low-income populations. Eighteen clinics were randomized to provide patients with either an intensive lifestyle intervention, which focused on reduced caloric intake and increased physical activity, or usual care. Patients in the intensive-lifestyle group participated in a high-intensity program delivered by health coaches embedded in the clinics. The program consisted of weekly sessions for the first 6 months, followed by monthly sessions for the remaining 18 months. Patients in the usual-care group received standard care from their primary care team. The primary outcome was the percent change from baseline in body weight at 24 months.
ClinicalTrials.gov Identifier: NCT02561221
The Examination of Mechanisms of Exercise-induced Weight Compensation (E-MECHANIC) trial compared the effect of two doses of exercise (8 kcal/kg of body weight/wk (KKW) or 20 KKW) on energy intake and body weight. The exercise groups were not provided with a dietary intervention and the study design also included a non-exercise control group.
clinicaltrials.gov Identifier: NCT01264406
