David W.L. Ma

David W.L. Ma
University of Guelph | UOGuelph · Department of Human Health and Nutritional Sciences (HHNS)

B.Sc., Ph.D.

About

181
Publications
28,855
Reads
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5,210
Citations
Additional affiliations
July 2017 - present
University of Guelph
Position
  • Chair
September 2007 - present
University of Guelph
Position
  • Professor (Associate)

Publications

Publications (181)
Article
Full-text available
Adopting a healthy diet remains central for the prevention of obesity. In adults, higher intake of ultra-processed food is associated with a greater risk of overweight and obesity. However, little is known about the degree of food processing and its association with anthropometric measures in families with preschool-aged children, a critical period...
Article
Purpose: To investigate the breakfast quality of preschool-aged children through a comparison of their energy and nutrient intakes at breakfast to published benchmarks for a balanced breakfast. Methods: Dietary data were collected for 163 children aged 3–5 years enrolled in the Guelph Family Health Study using one parent-reported online 24-hour rec...
Article
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Background The Canada's Food Guide (CFG) is recognized as the most prominent authoritative guideline for healthy eating in Canada. In 2019, Health Canada released the latest iteration of the CFG with substantial changes to its messaging and format from the previous 2007 CFG.Objective This study compared the awareness, use, knowledge, and opinions o...
Article
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Short-chain fatty acids (SCFA) produced from dietary non-digestible carbohydrate fermentation have metabolic effects in skeletal muscle; however, their effect on inflammatory mediator production is unknown. In this study, L6 myotubes were cultured with individual SCFA (acetate, propionate, and butyrate) at 0.5 mM and 2.5 mM ± 10 ng/mL lipopolysacch...
Article
To support Canadians ages 2 years and older in improving their dietary intake, Health Canada released a revised Canada’s Food Guide (CFG) in 2019. This study aimed to explore the knowledge and perceptions of the 2019 CFG among children ages 9–12 years old from Southwestern Ontario. From September–November 2021, interviews were conducted with childr...
Article
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There is limited research on the intake of non-nutritive sweeteners (NNS) among preschool-aged children. Canada’s Food Guide suggests limiting intake of NNS for all population groups and Health Canada recommends that young children (<2 years) avoid consuming beverages containing NNS. The aim of this study was to investigate the frequency and type o...
Article
Purpose: To determine if intake (servings/day) of total dairy and/or dairy subtypes (milk, cheese, and yogurt) were associated with biomarkers related to dyslipidemia, insulin sensitivity and inflammation in a sample of cardio-metabolically healthy young children from the Guelph Family Health Study at the University of Guelph, Guelph, Ontario, Cana...
Article
Background Zinc is an essential trace mineral that serves as a cofactor for the delta-5 and delta-6 desaturases (D5D, D6D) that are critical for long-chain polyunsaturated fatty acid (LC-PUFA) synthesis. While plasma zinc levels are generally reported to be associated with D5D and D6D indices in humans, it remains unclear if dietary zinc intake can...
Article
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Currently, peripheral tissue distribution of cannabinoids after treatment is poorly understood. This pilot study sought to examine the early tissue distribution of major cannabinoids 30 minutes following an intraperitoneal injection of vehicle (1:9 Tween 80/SAL), and doses of THC (1 mg/kg) and CBD (5 mg/kg) that are feasible for human consumption i...
Article
This study explored 1) the effect of applying an autocalibration algorithm on accelerometer data analyzed using different signal processing techniques and 2) how these techniques changed the signal composition. Using a dataset of preschoolers (n = 137; 4.31 ± 0.87 years; Actigraph accelerometers (100 Hz) on right hip 24 hours/7 days) the vector mag...
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Background American-style football (ASF) athletes are at risk for cardiovascular disease (CVD) and exhibit elevated levels of serum neurofilament light (Nf-L), a biomarker of axonal injury that is associated with repetitive head impact exposure over the course of a season of competition. Supplementation with the w-3 fatty acid (FA) docosahexaenoic...
Article
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Concussions and mild traumatic brain injury (m-TBI) have been identified as a consequential public health concern because of their potential to cause considerable impairments in physical, cognitive, behavioral, and social functions. Given their prominent structural and functional roles in the brain, n-3 polyunsaturated fatty acids (PUFA) have been...
Article
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Background: EPA and DHA n-3 FA play crucial roles in both neurological and cardiovascular health and high dietary intakes along with supplementation suggest potential neuroprotection and concussion recovery support. Rugby athletes have a high risk of repetitive sub-concussive head impacts which may lead to long-term neurological deficits, but ther...
Article
Sleep is vital for healthy development of young children; however, it is not understood how the quality and quantity vary between the weekends and weekdays (WE–WD). Research focused on older children has demonstrated that there is significant WE–WD variability and that this is associated with adiposity. It is unclear how this is experienced among p...
Article
This study investigated intakes of total, n-3, and n-6 polyunsaturated fatty acids (PUFA) in 109 preschool-aged children who participated in the Guelph Family Health Study pilot. Intakes of total, n-3, and n-6 PUFA did not meet recommendations. This study highlights the need for additional monitoring and potential interventions to improve PUFA inta...
Article
This study examined associations between child food involvement and food fussiness. Analyses used survey data from 62 children ages 1.5 to 5.9 years who participated in the Guelph Family Health Study Pilot. Overall involvement (β = –0.51, p = 0.02), involvement in meal preparation (β = –0.42, p = 0.009), and involvement in grocery shopping (β = –0....
Article
In January 2019, Health Canada released a revised Canada’s Food Guide (CFG). This study aimed to understand the perceptions of the 2019 CFG among Canadian parents with children aged 2–12 years. From October 2019–January 2020, 8 focus groups with parents from Southwestern Ontario were conducted using a semi-structured interview script focused on und...
Article
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Past research using hepatic rat microsomes showed that soy protein suppressed delta-6 desaturase activity (D6D) compared to casein (a dairy protein). The effects of soy and dairy on desaturase pathway activity in humans remain poorly investigated. The objective of this analysis was to investigate the association between soy and dairy consumption wi...
Article
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Background: Excessive intake of sugar in young children is a public health concern. Our study objectives were to examine intakes of total, free and added sugar among preschool-aged children and to investigate their associations with body weight, body mass index Z-scores, percent fat mass and waist circumference. Methods: The cross-sectional coho...
Article
Obesity is associated with inflammation and has been shown to increase breast cancer severity. The objective of this study was to examine the effect of FO supplementation in obesity-associated mammary tumorigenesis in the MMTV-neu(ndl)-YD5 mouse model of human epidermal growth factor receptor-2 positive BC. Female mice were fed one of three diets f...
Article
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Chronic stress is known to influence dietary choices, and stressed families often report poorer diet quality; however, little is known about how family-based stress is linked with dietary patterns that promote inflammation. This study investigated associations between family-based stress and the inflammatory potential of the diet among preschool-ag...
Article
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Purpose: To examine associations between preschoolers’ diet quality and parent and child socio-demographic variables. Methods: Cross-sectional analysis with 117 preschoolers. Parents reported socio-demographics and their children’s diet using 3-day food records. Diet quality was assessed using the Healthy Eating Index (HEI) 2015. Linear regression...
Article
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Measuring fatty acid (FA) levels in blood as a risk factor for chronic disease has been studied extensively. Previous research has used either plasma or serum samples to examine these associations. However, whether results from plasma and serum samples can be compared remains unclear, as differences in methodology related to the separation of plasm...
Article
Objective: This study aimed to explore barriers and facilitators of the provision of dairy and PBDA by parents of preschool-aged children, a previously unexplored area of research. Design: Five focus groups of parents were conducted and audio-recorded. Verbatim transcripts were analyzed using thematic analysis. Setting: University of Guelph, in G...
Article
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Given the focus on developing Dietary Reference Intakes (DRIs) based on chronic disease risk reduction and recent research for omega-3 long chain PUFA since the last DRI review, the Canadian Nutrition Society convened a panel of stakeholders for a 1-day workshop in late 2019. Attendees discussed the new NASEM guidelines for establishing DRI values...
Article
Objective This study examined the experiences, learnings, and strategies of Health Educators (HE) as they transitioned from a home-based model for motivational interviewing (MI) to remote delivery during COVID-19. The overall goal of this paper is to identify key lessons learned to help inform future delivery of remote MI delivery. Methods HE perc...
Article
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Dietary fatty acids (FA) are essential for overall human health, yet individual FA reference ranges have yet to be established. Developing individual FA reference ranges can provide context to reported concentrations and whether an individual displays deficient, or excess amounts of FA. Reference ranges of sixty-seven individual FA (μmol/L) were pr...
Article
Objective To examine the association between self-reported food skills and diet quality along with measured food waste among a sample of Canadian parents. Design Cross-sectional data from surveys to assess food skills, 3-day food records to assess the Healthy Eating Index (HEI)-2015, and food waste measured by household waste audits. Setting Guel...
Article
Full-text available
Lifestyle habits, such as the consumption of a healthy diet, may prevent up to 30–50% of breast cancer (BC) cases. Dietary fats are of specific interest, as research provides strong evidence regarding the association of dietary fats and BC. However, there is limited research on the role of different types of fats including polyunsaturated (PUFA), m...
Article
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Taste is a fundamental mechanism whereby compounds are detected orally, yet it is highly variable among individuals. The variability in taste that is attributable to genetics is not well-characterized despite its potential role in food selection and therefore eating habits that contribute to risk of overweight and obesity. In order to implicate mea...
Article
This study compares sleep outcome measures obtained using normal- and low-frequency extension (LFE) settings (Actilife). Forty-two children (aged 3–6 years) were instructed to wear an ActiGraph GT3X+ accelerometer on their hip for 7 days, 24 h/day. Total sleep time (min), sleep efficiency (%), and number and cumulative length (min) of awakening wer...
Article
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The COVID-19 pandemic has disrupted many aspects of daily life. The purpose of this study was to identify how health behaviors, level of stress, financial and food security have been impacted by the pandemic among Canadian families with young children. Parents (mothers, n = 235 and fathers, n = 126) from 254 families participating in an ongoing stu...
Article
Obese adipose tissue (AT) inflammation is partly driven by accumulation of CD4⁺ T helper (Th)1 cells and reduced Th2 and T regulatory (Treg) subsets, which promotes macrophage chemotaxis and ensuing AT metabolic dysfunction. This study investigated CD4⁺ T cell/adipocyte cytokine-mediated paracrine interactions (cross-talk) as a target for dietary i...
Article
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Parents’ stress is independently associated with increased child adiposity, but parents’ stress may also interfere with childhood obesity prevention programs. The disruptions to the family dynamic caused by participating in a behaviour change intervention may exacerbate parent stress and undermine overall intervention efficacy. This study explored...
Article
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Background: Higher diet quality has been associated with greater amounts of food waste among adults in the United States. This study aims to build on previous work by examining the association between diet quality and food waste, as assessed using detailed waste audits, among a sample of Canadian families. Methods: This cross-sectional study use...
Article
Purpose: To investigate dairy and plant-based dairy alternatives (DPBDA) purchasing habits, including comparisons among locations of purchase and among subtypes of DPBDA, of families with preschool-aged children. Methods: Expenditures on food and DPBDA were calculated using grocery and food receipts collected for 3 weeks from 51 households in and...
Preprint
Full-text available
Background : Higher diet quality has been associated with greater amounts of food waste among adults in the United States. This study aims to build on previous work by examining the association between diet quality and food waste, as assessed using detailed waste audits, among a sample of Canadian families. Methods : This cross-sectional study used...
Article
Full-text available
The revised version of Canada’s Food Guide, released in January 2019, issued new guidance by combining meat and alternatives with milk and alternatives into a single group called “protein foods” and emphasized selecting plant-based foods from this category more often. Though the changes represent a simple depiction of a healthy plate, the new Food...
Article
Stress may influence the parenting practices employed by parents to manage their children’s screen-time. The objective of this study was to examine cross-sectional associations between family stress and media parenting practices. Using the Guelph Family Health Study Pilot 2 cohort, data was collected from 64 parents from 39 families. Linear regress...
Article
Full-text available
Objective: The purpose of the study was to assess knowledge and perceptions related to carbohydrates, including sugars, among Canadian nutrition-major undergraduates compared to those enrolled in elective nutrition courses (i.e., “nutrition-elective students”). Methods: Cross-sectional surveys were distributed during class time at eight Canadian un...
Article
Full-text available
Sports-related concussions (SRC) are traumatic brain injuries induced as the result of a biomechanical force to the body that temporarily impair neurological functions. Not all traumatic impacts reach the threshold necessary to produce concussive symptoms; however, the culmination of these events is known as a subconcussive impact (SCI). Athletes w...
Article
Reward-processing impairment is a common symptomatic dimension of several psychiatric disorders. However, whether the underlying pathological mechanisms are common is unknown. Herein, we asked if the decrease in the n-3 polyunsaturated fatty acid (PUFA) lipid species, consistently described in these pathologies, could underlie reward-processing def...
Preprint
Full-text available
Background: Higher diet quality has been associated with greater amounts of food waste among adults in the United States. This study aims to build on previous work by examining the association between diet quality and food waste, as assessed using detailed waste audits, among a sample of Canadian families. Methods: This cross-sectional study used d...
Article
Objective This study investigated associations between stress (general stress, parenting distress, and household chaos) and adiposity among parents of young children. Methods The sample consisted of 49 mothers and 61 fathers from 70 families with young children living in Ontario, Canada. Linear regression using generalized estimating equations was...
Article
Full-text available
There is limited information on feeding egg-type chick breeders n-3 polyunsaturated fatty acids (PUFA) and its impact on hatching egg quality and embryonic fatty acid (FA) utilization. We investigated the effects of feeding brown and white egg-type chick breeders diets containing sources of n-3 PUFA on egg composition, apparent embryonic FA utiliza...
Article
Objective: This study explored the feasibility and acceptability of using Motivational Interviewing (MI) in the home setting with families of preschoolers. Methods: Using mixed-methods pilot data from an MI-based obesity prevention intervention delivered via home visits by health educators (HEs) with 44 families (n = 17 four home visit group; n...
Article
Full-text available
Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been associated with reduced breast cancer risk; however, the exact mechanism remains elusive. Female wildtype (WT) and fat-1 mice were fed a 10% safflower diet until 6 weeks of age. Mammary gland epithelial cells (EC) were isolated and EC populations were determined by CD24 surface expression. Fa...
Article
Obese visceral adipose tissue (AT) inflammation is driven by adipokine-mediated cross talk between CD8+ T cells and adipocytes, a process mitigated by long-chain (LC) n-3 polyunsaturated fatty acids (PUFA) but underlying mechanisms and ensuing effects on macrophage polarization status are unknown. Using an in vitro co-culture model that recapitulat...
Article
Purpose: To explore the associations between family meal context and overall diet quality of Canadian preschool-aged children. Methods: Cross-sectional analysis of 95 preschool-aged children from 72 families. Measures about health behaviours and the family meal environment were drawn from selected questionnaire items. Three-day food records for chi...
Article
Full-text available
The Commission for Environmental Cooperation (CEC) has estimated that Canadian households waste 85 kg of food per person annually. Food waste has become an increasingly common focus for policy, regulation, interventions, and awareness-raising efforts in Canada. However, there is still a relative dearth of data to inform such decision-making process...
Article
Impaired intestinal health characterized by a dysbiotic microbial community and a dysfunctional epithelial barrier contributes to host inflammation and metabolic dysfunction in obesity. Fish oil (FO)-derived n-3 polyunsaturated fatty acids have been shown to improve aspects of the obese phenotype; however, their effect on obese intestinal health is...
Article
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Background: People living with human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) (PLWH) are at an increased risk of cardiovascular disease. Diet-related factors may contribute. The aim of this pilot study was to determine, in PLWH, the relationship between atherosclerosis assessed by carotid intima-media thi...
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On September 22, 2017, “Engaging the Forgotten Parent: Conference of Experts on Fathers’ Role in Children’s Weight‐Related Behaviours and Outcomes” brought researchers, students, health professionals, community stakeholders, and knowledge users from Canada, Australia, and the United States together to Toronto, Ontario, for a 1‐day gathering focused...
Article
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Background Home-based lifestyle behaviour interventions show promise for treating and preventing childhood obesity. According to family theories, engaging the entire family unit, including parents, to change their family behaviour and dynamics may be necessary to prevent the development of childhood obesity. However, little is known about how these...
Article
Full-text available
Evidence for a relationship between omega-6/omega-3 (n-6/n-3) polyunsaturated fatty acid (PUFA) ratio and obesity in humans is inconsistent, perhaps due to differences in dietary intake or metabolism of PUFAs between different subsets of the population. Since chronic inflammation is central to obesity and inflammatory pathways are regulated by PUFA...
Article
Full-text available
Taste is fundamentally important for food selection. Although measures of taste sensitivity and preference have been refined over several decades, it remains largely unknown how these measures relate to each other and to food preferences. The objectives of this study were to examine, in healthy adults (age 24.6 ± 0.6 years, n = 49), 1) correlations...
Article
Fatty acid desaturase 2 (Fads2) encodes the delta-6 desaturase (D6D) enzyme, which is rate-limiting for the endogenous production of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). Numerous studies have reported the cardiometabolic health benefits of omega-3 LC-PUFA. Humans carrying genetic variants in the FADS2 gene have reduced levels o...
Article
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Background A major contributor to the growing obesity crisis is screen based sedentary behaviour among young children. Media parenting practices may be an important determinant of children’s screen time, however published research exploring the influence of parenting practices on children’s screen time has mainly focused on children’s television us...
Article
Objective: The aim of this study was to determine whether hepatic gene expression related to hepatocellular carcinoma (HCC) is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease (NAFLD). Methods: In a cross-sectional study, the associations between hepatic gene expression and liver histology, i...
Article
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Background With 1 in 4 Canadian preschoolers considered overweight or obese, identifying risk factors for excess weight gain and developing effective interventions aimed at promoting healthy weights and related behaviours among young children have become key public health priorities. Despite the need for this research, engaging and maintaining part...
Article
Full-text available
Taste is a fundamental determinant of food selection, and inter-individual variations in taste perception may be important risk factors for poor eating habits and obesity. Characterizing differences in taste perception and their influences on dietary intake may lead to an improved understanding of obesity risk and a potential to develop personalize...
Article
Dietary fatty acids are associated with the development of many chronic diseases, such as obesity, diabetes, cardiovascular disease, metabolic syndrome, and several cancers. This review explores the literature surrounding the combined and individual roles of n-6 PUFAs linoleic acid (LA) and arachidonic acid (AA) as they relate to immune and inflamm...