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Introduction
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July 2012 - present
Publications
Publications (230)
Exogenous ketone monoesters can raise blood β-OHB and lower glucose without other nutritional modifications or invasive procedures. However, unpleasant taste and potential gastrointestinal discomfort may make adherence to supplementation challenging. Two novel ketone supplements promise an improved consumer experience but differ in their chemical p...
New findings:
What is the topic of this review? The integrative physiological response to exogenous ketone supplementation. What advances does it highlight? The physiological effects and therapeutic potential of exogenous ketones on metabolic health, cardiovascular function, cognitive processing, and modulation of inflammatory pathways and immune...
Objective
To investigate the effect of acute submaximal exercise, based on the spinal cord injury (SCI) Exercise Guidelines, on cognition and brain-derived neurotrophic factor (BDNF) in people with SCI.
Design
Eight adults (7 males) with traumatic SCI volunteered in this pre-registered pilot study. In randomized order, participants completed subma...
New findings:
What is the central question of this study? Does acute ketone monoester supplementation enhance the recovery of muscle force and modulate circulating cytokine concentrations after muscle-damaging eccentric exercise? What is the main finding and its importance? We report that ketone monoester supplementation increased plasma β-hydroxy...
Background
Recently developed exogenous ketone monoester supplements can acutely raise blood β-OHB and lower blood glucose without the need for other nutritional modifications or invasive procedures. However, unpleasant taste and the potential for gastrointestinal discomfort may make adherence to a supplement regimen challenging. Two novel ketone s...
Individuals with spinal cord injury (SCI) may experience cardiovascular, musculoskeletal and organ function dysregulation. Sequelae include reduced catecholamine secretion and attenuated immune responses which may impact exercise-induced leukocytosis. The purpose of this study was to characterize major leukocyte subtypes following 30 minutes of acu...
Objectives
Exogenous ketone (monoester or salt) supplements are increasingly being employed for a variety of research purposes and marketed amongst the general public for their ability to raise blood beta-hydroxybutyrate (β-OHB). Emerging research suggests a blood glucose-lowering effect of exogenous ketones. Here, we systematically review and meta...
Interleukin-10 (IL-10) inhibits pro-inflammatory cytokine production in blood leukocytes - an effect mediated by signal transducer and activator of transcription 3 (STAT3) activation. To examine potential sex-based differences in IL-10's anti-inflammatory function, we treated whole blood from healthy males and females (n=16 each; age: 28±6 years; b...
Chronic, low-grade inflammation is associated with the development of numerous diseases and is mediated in part by overactivation of the NLRP3 inflammasome. The ketone body beta-hydroxybutyrate (βHB) suppresses the NLRP3 inflammasome and alters intracellular signalling pathways in vitro and in animal models; however, this effect has not yet been sh...
Recently developed ketone (monoester or salt) supplements acutely elevate blood β-hydroxybutyrate (BHB) exogenously without prolonged periods of fasting or carbohydrate restriction. Previous (small-scale) studies have found a blood glucose-lowering effect of exogenous ketones. This study aimed to systematically review available evidence and conduct...
Spinal cord injury chronically alters cardiac structure and function and is associated with increased odds for cardiovascular disease. Here, we investigate the cardiac consequences of spinal cord injury on the acute-to-chronic continuum, and the contribution of altered bulbospinal sympathetic control to the decline in cardiac function following spi...
Background
Low-carbohydrate ketogenic diets are a viable method to lose weight that have regained popularity in recent years. Technology in the form of mobile health (mHealth) apps allows for scalable and remote delivery of such dietary interventions and are increasingly being used by the general population without direct medical supervision. Howev...
Key points:
Exercise training is well-known to improve metabolic health in obesity - but how exercise modifies the structure and metabolic function of adipose tissue, in absence of weight loss, remains unclear. We report that 12 weeks of moderate-intensity continuous training (MICT) and 12 weeks of high-intensity interval training (HIIT) both indu...
Diabetes is characterized by an impaired ability to appropriately control blood glucose. Postprandial hyperglycemia, in particular, is associated with complications in people with type 1 diabetes (T1D) and type 2 diabetes (T2D). The objective of this study was to determine how sugar-free dark chocolate sweetened with stevia, erythritol, and inulin...
Background
The gut microbiome has been associated with cardiorespiratory fitness.
Objective
To assess the effects of oligofructose (FOS)-enriched inulin supplementation on the gut microbiome and the peak oxygen uptake (V̇O2peak) response to high-intensity interval training (HIIT).
Methods
The study was a randomized controlled trial. Forty sedenta...
Abstract Background Low cardiorespiratory fitness (V̇O2peak) is highly associated with chronic disease and mortality from all causes. Whilst exercise training is recommended in health guidelines to improve V̇O2peak, there is considerable inter-individual variability in the V̇O2peak response to the same dose of exercise. Understanding how genetic fa...
Secondary analysis of aggregated case series data.
To examine the effects of a high-fat/high-carbohydrate meal on leukocyte populations in adults with a chronic SCI.
University-based laboratories in British Columbia, Canada.
Ten individuals (M = 9) with a traumatic SCI (>1-year post-injury; M = 15.5 years; n = 2 sensory complete, n = 7 motor comple...
Adults with obesity are at increased risk of neurocognitive impairments, partly as a result of reduced cerebral blood flow and brain-derived neurotrophic factor (BDNF). Ketone supplements containing β-hydroxybutyrate (β-OHB) are a purported therapeutic strategy for improving brain health in at-risk populations. We tested the hypothesis that short-t...
Circulating concentrations of canonically pro- and anti-inflammatory cytokines are commonly measured when evaluating the anti-inflammatory effects of exercise. An important caveat to interpreting systemic cytokine concentrations as evidence for the anti-inflammatory effects of exercise is the observed dissociation between circulating cytokine conce...
BACKGROUND
Low-carbohydrate ketogenic diets are a viable method to lose weight that have regained popularity in recent years. Technology in the form of mobile health (mHealth) apps allows for scalable and remote delivery of such dietary interventions and are increasingly being used by the general population without direct medical supervision. Howev...
Type 2 diabetes can be treated, and sometimes reversed, with dietary interventions; however, strategies to implement these interventions while addressing medication changes are lacking. We conducted a 12-week pragmatic, community-based parallel-group randomized controlled trial (ClinicalTrials.gov: NCT03181165) evaluating the effect of a low-carboh...
The global pandemics of obesity and sedentarism are associated with poor quality of life and increased risks for development of inflammatory chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. Physical activity is considered as an antidote to counteract the development of chronic sterile inflammatory diseases. Thus, we...
The prevalence of Type 2 diabetes (T2D) is increasing, which creates a large economic burden. Diet is a critical factor in the treatment and management of T2D; however, there are a large number of dietary approaches and a general lack of consensus regarding the efficacy of each. Therefore, the purpose of this narrative review is twofold: (1) to cri...
Objectives
To examine whether sex-specific associations between baseline PA level and follow up cognitive performance in Chinese subjects exist from the China Health and Retirement Longitudinal study (CHARLS).
Method
A total of 3395 adults aged 45 or old from the CHARLS were used for analysis. The combined scores of measurements of mental status a...
Background
LDL particle size and number (LDL-P) are emerging lipid risk factors. Nonsystematic reviews have suggested that diets lower in carbohydrates and higher in fats may result in increased LDL particle size when compared with higher-carbohydrate diets.
Objectives
This study aimed to systematically review available evidence and conduct meta-a...
Objective
To determine whether a Mediterranean-style ketogenic diet mobile health application (app) with breath acetone biofeedback is superior to a calorie-restricted low-fat diet app in promoting weight loss.
Methods
Participants (N = 155) with overweight/obesity (mean±SD: 41±11 y, BMI = 34±5 kg/m², 71% female) were randomized to one of the inte...
Objectives
To test the hypotheses that Bulletproof Coffee (a blended drink containing coffee, medium-chain triglyceride [MCT] oil, and grass-fed ghee) will acutely improve cognitive function and lead to greater satiety when compared to black coffee.
Methods
This study uses a single-blind, counterbalanced, randomized cross-over design with each par...
Objectives
Low-carbohydrate, high-fat “ketogenic” food supplements have become increasingly popular in recent years with claims of improving body composition and cognition, while reducing hunger. However, acute consumption of high-fat foods has been shown to promote dietary endotoxemia; the release of bacterial lipopolysaccharide from the gut into...
Understand the acute inflammatory disturbances is important for preventing early diabetes and obesity-related complications. This study aimed to determine whether breaking up prolonged sitting into brief several shorter bouts spread throughout the day (“exercise snacks”) associated a short-term dietary intervention (low- or high-carbohydrate) have...
An amendment to this paper has been published and can be accessed via the original article.
There is growing interest in the effect of exogenous ketone body supplementation on exercise responses and performance. The limited studies to date have yielded equivocal data, likely due in part to differences in dosing strategy, increase in blood ketones, and participant training status. Using a randomized, double-blind, counterbalanced design, w...
Background
Postprandial hyperglycemia increases systemic inflammation and is a risk factor for cardiovascular disease. A ketone monoester (KME) drink containing β-hydroxybutyrate (β-OHB) rapidly lowers plasma glucose, which may be a strategy protecting against postprandial hyperglycemia. We hypothesized that KME would attenuate 2-hour postprandial...
Healthy males (n = 10; age: 24 ± 4 years; body mass index: 24 ± 2 kg·m ⁻² ) completed 2 randomized conditions separated by ≥48 h involving 6–8.5 h of sitting with (“stair snacks”) and without (sedentary) hourly staircase sprint interval exercise (∼14–20 s each). Resting blood flow and shear rates were measured in the femoral artery, internal caroti...
Purpose: To report pilot test findings on whether in-task affect during a supervised exercise program, where participants were randomized to either moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT), predicts changes in moderate-to-vigorous physical activity (MVPA-Total and MVPA10+ in bouts of ≥ 10 min) at 1- a...
Brain-derived neurotrophic factor (BDNF) is important for brain and metabolic function. Ingestion of a ketone monoester (KME) drink containing beta-hydroxybutyrate (β-OHB) attenuates hyperglycemia in humans and increases neuronal BDNF in rodents. Whether KME affects BDNF in humans is currently unknown. This study examined the effect of KME ingestio...
Purpose:
Prolonged sitting is associated with cardiometabolic complications. The study purpose was to investigate whether breaking up prolonged sitting with brief stair climbing exercise "snacks" could lower postprandial insulin, glucose and free fatty acids responses.
Methods:
In two separate randomized crossover studies, 12 young healthy weigh...
Objective
We compared the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on insulin sensitivity and other important metabolic adaptations in adults with obesity.
Methods
Thirty-one inactive adults with obesity (age: 31±6 years, BMI: 33±3 kg/m2) completed 12 weeks (4 sessions/week) of either HII...
Activation of the NOD-like receptor pyrin-domain containing 3 (NLRP3) inflammasome is associated with chronic low-grade inflammation in metabolic diseases such as obesity. Mechanistic studies have shown that β-hydroxybutyrate (OHB) attenuates activation of NLRP3, but human data are limited. In a randomized, double-blind, placebo-controlled crossove...
In type 2 diabetes, liver insulin resistance and excess hepatic glucose production results in elevated fasting glucose. A bedtime snack has been recommended to improve fasting glucose, yet there is little evidence supporting this recommendation. Moreover, the optimal composition of a bedtime snack is unknown.
Purpose
To determine whether a low-car...
Type 2 diabetes (T2D) is among the most prevalent non-communicable lifestyle diseases. We propose that overnutrition and low levels of physical activity can contribute to a vicious cycle of hyperglycemia, inflammation and oxidative stress, insulin resistance, and pancreatic β-cell dysfunction. The pathophysiological manifestations of T2D have a par...
Background:
The current treatment paradigm for type 2 diabetes mellitus (T2D) typically involves use of multiple medications to lower glucose levels in hope of reducing long-term complications. However, such treatment does not necessarily address the underlying pathophysiology of the disease and very few patients achieve partial, complete, or prol...
Exercise-induced increases in peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and p53 protein content in the nucleus mediate the initial phase of exercise-induced mitochondrial biogenesis. Here we investigated if exercise-induced increases in these and other markers of mitochondrial biogenesis were altered after 40 sessions of...
This review considers the physiological basis of brief vigorous exercise to improve health, with a focus on cardiorespiratory fitness (CRF) and glycaemic control, and the potential underlying mechanisms involved. We defined 'brief' as a protocol lasting ≤15 min including warm-up, cool-down and recovery, and involving a total of ≤5 min of 'vigorous'...
Exercise-induced increases in peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and p53 protein content in the nucleus mediate the initial phase of exercise-induced mitochondrial biogenesis. Here we investigated if exercise-induced increases in these and other markers of mitochondrial biogenesis were altered after 40 sessions of...
Background:
Exogenous ketones make it possible to reach a state of ketosis that may improve metabolic control in humans.
Objectives:
The main objective of this study was to determine whether the ingestion of a ketone monoester (KE) drink before a 2-h oral-glucose-tolerance test (OGTT) would lower blood glucose concentrations. Secondary objective...
Aim
To examine the effect of walking before dinner on 24-h glycemic control in individuals with type 2 diabetes using the standardized multi-site Exercise-Physical Activity and Diabetes Glucose Monitoring (E-PAraDiGM) Protocol.
Methods
Eighty participants were studied under two conditions (exercise vs. non-exercise control) separated by 72 h in a...
Purpose
Sprint interval training (SIT), involving brief intermittent bursts of vigorous exercise within a single training session, is a time-efficient way to improve cardiorespiratory fitness (CRF). It is unclear whether performing sprints spread throughout the day with much longer (≥ 1 h) recovery periods can similarly improve CRF, potentially all...
Background
The breakfast meal often results in the largest postprandial hyperglycemic excursion in people with type 2 diabetes.
Objective
Our purpose was to investigate whether restricting carbohydrates at breakfast would be a simple and feasible strategy to reduce daily exposure to postprandial hyperglycemia.
Design
Adults with physician-diagnosed...
Background
Age-related hearing loss (HL) is a prevalent disability associated with loneliness, isolation, declines in cognitive and physical function and premature mortality. Group audiological rehabilitation (GAR) and hearing technologies address communication and cognitive decline. However, the relationship between loneliness, physical function a...
Background: Worldwide incidence of type 2 diabetes (T2D) is rapidly increasing. Given the numerous negative health consequences associated with T2D, prevention of this disease has become a priority. Lifestyle changes, including regular exercise, can reduce the onset of T2D in those at elevated risk. However, long-term adherence to exercise is often...
Scope
Recent cell culture studies indicate that the ketone body β‐hydroxybutyrate (β‐OHB) directly inhibits the NLRP3 inflammasome, which plays an important role in regulating inflammation. However, direct evidence demonstrating this effect in humans is lacking.
Methods and Results
To determine the effects of acutely raising blood β‐OHB in healthy...
Postprandial hyperglycemia has been linked to elevated risk of cardiovascular disease. Endothelial dysfunction and/or damage may be one of the mechanisms through which this occurs. In this exploratory study, we determined whether acute glucose ingestion would increase markers of endothelial damage/activation and impair endothelial function before a...
There is heterogeneity in the observed O2peak response to similar exercise training, and different exercise approaches produce variable degrees of exercise response (trainability). The aim of this study was to combine data from different laboratories to compare O2peak trainability between various volumes of interval training and Moderate Intensity...
We investigated the effect of stair climbing exercise "snacks" on peak oxygen uptake. Sedentary young adults were randomly assigned to perform 3 bouts/day of vigorously ascending a 3-flight stairwell (60 steps), separated by 1-4 h of recovery, 3 days/week for 6 weeks, or a nontraining control group (n = 12 each). Peak oxygen uptake was higher in th...
Lowering carbohydrate consumption effectively lowers glucose but impacts on inflammation are unclear. The objectives of this study were to: 1) Determine whether reducing hyperglycemia by following a low-carbohydrate high-fat (LCHF) diet could lower markers of innate immune cell activation in type 2 diabetes (T2D); and 2) Examine if the combination...
BACKGROUND
Worldwide incidence of type 2 diabetes (T2D) is rapidly increasing. Given the numerous negative health consequences associated with T2D, prevention of this disease has become a priority. Lifestyle changes, including regular exercise, can reduce the onset of T2D in those at elevated risk. However, long-term adherence to exercise is often...
A key pathological component of obesity is chronic low-grade inflammation, which is propagated by infiltration of immune cells into tissues and overproduction of pro-inflammatory cytokines. Cytokines that possess anti-inflammatory properties, such as interleukin (IL)-10 and IL6, may also play an important role. This study was designed to determine...
We examined the effect of brief intermittent stair climbing exercise on glycemic control using continuous glucose monitoring in people with type 2 diabetes (n = 7, 5 men; 2 women; age, 21-70 years). The protocol involved three 60-s bouts of vigorously ascending and slowly descending a flight of stairs. Mean 24-h blood glucose was unchanged after an...
Purpose:
High-intensity interval training (HIIT) may lead to superior cardiometabolic improvements when compared to moderate-intensity continuous training (MICT). However, adherence to HIIT requires examination. The purpose of this pilot study was to examine moderate-to-vigorous physical activity (MVPA) adherence 24 weeks following a brief counsel...
Background
The trillions of bacteria residing along the mammalian intestine, referred to as the gut’s microbiome, are integral in various physiological function of their host. Disruptions in these communities, or dysbiosis, are implicated in various illnesses such as inflammatory bowel disease and colorectal cancer. Many factors such as diet, metho...
Key points:
The recent development of exogenous ketone supplements allows direct testing of the metabolic effects of elevated blood ketones without the confounding influence of widespread changes experienced with ketogenic diets or prolonged fasting. In the present study, we determined the effect of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone...
High intensity interval training (HIIT) elicits health benefits but it is unclear how HIIT impacts sedentary behaviour. In this preliminary study, we compared the effects of supervised HIIT or moderate intensity continuous training (MICT) on sedentary time in overweight/obese adults. In both groups, percentage of time spent in sedentary activities...
Aim
The purpose of this study was to examine whether the combination of high-intensity interval training (HIIT) and post-exercise protein supplementation would improve cardiovascular outcomes in individuals with T2D.
Methods
In a double-blind controlled trial, fifty-three adults with T2D (free of CVD and not on exogenous insulin) were randomized...
Developing non-invasive alternatives to monitor insulin levels in humans holds potential practical value for identifying individuals with, or at risk of developing, insulin resistance. The aims of this study were: (1) to determine if saliva insulin can be used to delineate between low and high postprandial insulin levels following the ingestion of...
Postprandial hyperglycemia has deleterious effects on endothelial function. Restricting carbohydrate intake and postmeal walking have each been shown to reduce postprandial hyperglycemia, but their combination and subsequent effects on endothelial function have not been investigated. Here, we sought to examine the effect of blunting postprandial hy...
