Development, validity and reliability assessment of the Canadian Food Literacy Measure.

Food literacy is a growing area of interest given its potential to support healthy and sustainable diets. Most existing food literacy measures focus on nutrition and food skills but fail to address food systems and socio-environmental aspects of food literacy. Further, measures developed and tested in the Canadian context are lacking. The objective of this project was to develop and test the validity and reliability of a brief self-administered measure, in French and English, designed to assess multiple dimensions of food literacy among adults living in Canada. The 23-item Canadian Food Literacy Measure was developed through an iterative process that included assessment of face and content validity through expert review (n=20) and cognitive interviews (n=20), and construct validity and reliability, i.e., internal consistency through an online survey (n=154). The results indicate that the measure is well understood by both English- and French-speaking adults. The measure's construct validity is demonstrated by the observed differences in total scores in hypothesized directions by gender (p=0.003), age (p=0.007), education level (p=0.002), health literacy (p<0.001) and smoking status (p=0.001) and the significant positive correlation (r = 0.29; p=0.002) between total scores and fruit and vegetable intake. The measure also has high internal consistency with a Cronbach's coefficient alpha of 0.80. This measure can be used in surveillance studies to provide insight into the food literacy of adults living in Canada and in epidemiologic research that aims to explore how food literacy is associated with a variety of health outcomes.

Construct validity and reliability of the Canadian Eating Practices Screener to assess eating practices based on 2019 Canada's Food Guide recommendations.

For the first time since its introduction, the 2019 Canada's Food Guide (2019-CFG) highlighted specific guidance on eating practices, i.e., recommendations on where, when, why, and how to eat. The Canadian Eating Practices Screener / Questionnaire court canadien sur les pratiques alimentaires was developed to assess eating practices based on the 2019-CFG healthy eating recommendations. The objective of this cross-sectional study was to assess the construct validity and reliability of the Canadian Eating Practices Screener. From July to December 2021, adults (n = 154) aged 18-65 years completed a sociodemographic questionnaire and the screener. Construct validity was assessed by examining variability in screener scores, by comparing screener scores among subgroups with hypothesized differences in eating practices, and by examining the correlation between screener scores and fruit and vegetable intake. Reliability, i.e., internal consistency, was assessed by calculating Cronbach's coefficient alpha. Screener item scores were summed to provide a total score ranging from 21 to 105. The mean screener score was 76 (SD = 8.4; maximum, 105), ranging from 53 (1st percentile) to 92 (99th percentile). Differences in total scores in hypothesized directions were observed by age (p = 0.006), perceived income adequacy (p = 0.09), educational attainment (p = 0.002), and smoking status (p = 0.09), but not by gender or health literacy level. The correlation between screener scores and fruit and vegetable intake was 0.29 (p = 0.002). The Cronbach's coefficient alpha was 0.79, suggesting acceptable to high internal consistency. Study findings provide preliminary evidence of the screener's construct validity and reliability, supporting its use to assess eating practices based on the 2019-CFG healthy eating recommendations.

The Canadian Food Intake Screener for assessing alignment of adults' dietary intake with the 2019 Canada's Food Guide healthy food choices recommendations: scoring system and construct validity.

NOVELTY: The Canadian Food Intake Screener was developed to rapidly assess alignment of dietary intake with the Canada's Food Guide-2019 healthy food choices recommendations. Scoring is aligned with the Healthy Eating Food Index-2019 to the extent possible. Among a sample of adults, reasonable variation in screener scores was noted, mean screener scores differed between some subgroups with known differences in diet quality, and a moderate correlation between screener scores and total Healthy Eating Food Index-2019 scores based on repeat 24 h dietary recalls was observed. The Canadian Food Intake Screener has moderate construct validity for rapid assessment of overall alignment of adults' dietary intake with the Canada's Food Guide-2019 healthy food choices recommendations.

Dietary interventions for perinatal depression and anxiety: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Dietary interventions are a widely available mediation for depression and anxiety among pregnant and/or postpartum (i.e., perinatal) persons, but their effectiveness is not well known. OBJECTIVES: We performed a systematic review and meta-analysis to assess the effectiveness of dietary interventions for the treatment of perinatal depression and/or anxiety. METHODS: We searched MEDLINE, EMBASE, PsycINFO, CINAHL, and Web of Science from their inception to 2 November, 2022. Studies were included if they were available in English and examined the effectiveness of a dietary intervention for perinatal depression and/or anxiety in a randomized controlled trial. RESULTS: Our search identified 4246 articles, of which 36 were included and 28 were eligible for meta-analysis. Random-effects meta-analyses were performed. Polyunsaturated fatty acids (PUFAs) were not found to improve symptoms of perinatal depression compared to control conditions [standardized mean differences (SMD): -0.11; 95% CI: -0.26 to 0.04]. These results neither changed when examined during pregnancy or the postpartum period separately nor varied according to the fatty acid (FA) ratio. Elemental metals (iron, zinc, and magnesium) were also not found to be superior to placebo (SMD: -0.42; 95% CI: -1.05 to 0.21), although vitamin D yielded a small to medium effect size improvement (SMD: -0.52; 95% CI: -0.84 to -0.20) in postpartum depression. Iron may help in those with confirmed iron deficiency. Narrative synthesis was performed for studies ineligible for meta-analyses. CONCLUSIONS: Despite their widespread popularity, PUFAs and elemental metals do not appear to effectively reduce perinatal depression. Vitamin D taken in doses of 1800-3500 International Units per day may be, to some extent, promising. Additional high-quality, large-scale randomized controlled trials are needed to determine the true effectiveness of dietary interventions on perinatal depression and/or anxiety. This study was registered at PROSPERO (registration date: 5 July, 2020; CRD42020208830).

Individualized high dairy protein + walking program supports bone health in pregnancy: a randomized controlled trial.

BACKGROUND: Pregnancy induces bone mineral mobilization, which may be further compromised if diet and physical activity are suboptimal. OBJECTIVES: We aimed to determine the effects of a Nutrition + Exercise intervention during pregnancy on maternal calciotropic and bone biomarker profiles throughout pregnancy and the postpartum. METHODS: In the Be Healthy in Pregnancy (BHIP) randomized controlled trial, 203 of 225 participants who consented to the bone health substudy were, randomly assigned at 12-17 weeks gestation to receive either usual care (control) or a structured and monitored Nutrition + Exercise plan (intervention) providing an individualized high dairy protein diet and a walking program throughout pregnancy. Maternal serum total procollagen type 1 N-terminal propeptide (P1NP; bone formation), C-terminal telopeptide of type I collagen (CTX; bone resorption), and insulin-like growth factor-1 (IGF-1) were measured by ELISA, and vitamin D metabolites by ultra-performance LC tandem MS at early and late pregnancy, 6 mo postpartum, and in cord blood. RESULTS: In 187 participants completing all measures, significantly higher intakes were observed in the intervention than in the control group for total protein (P < 0.0001), protein intake from dairy foods (P < 0.0001), and calcium (P < 0.0001), whereas vitamin D intake was similar between treatment groups in both the second and third trimesters. The intervention group had significantly lower serum CTX at end of pregnancy (mean ± SD: 0.78 ± 0.31 ng/mL; n = 91 compared with 0.89 ± 0.33 ng/mL; n = 96, P = 0.034) and in cord serum (0.58 ± 0.13 ng/mL; n = 31 compared with 0.69 ± 0.18 ng/mL; n = 22, P < 0.025). Serum concentrations of P1NP rose significantly (P < 0.02) from early pregnancy to 6 mo postpartum for the intervention group only. Serum 25-hydroxyvitamin D status was >50 nmol/L for 97% of all participants. CONCLUSIONS: Higher maternal dietary protein and calcium intakes than usual care in concert with normal vitamin D status minimized bone resorption and maintained bone formation and may protect bone health during pregnancy.This trial was registered at clinicaltrials.gov as NCT01689961.

Be Healthy in Pregnancy (BHIP): A Randomized Controlled Trial of Nutrition and Exercise Intervention from Early Pregnancy to Achieve Recommended Gestational Weight Gain.

A randomized two-arm prospective superiority trial tested the efficacy of a novel structured and monitored nutrition (bi-weekly counselling for individualized energy and high dairy protein diet) and exercise program (walking goal of 10,000 steps/day) (intervention) compared to usual care (control) in pregnant women to achieve gestational weight gain (GWG) within current recommendations. Women recruited in communities in southern Ontario, Canada were randomized at 12-17 weeks gestation with stratification by site and pre-pregnancy BMI to intervention (n = 119) or control (n = 122). The primary outcome was the proportion of women who achieved GWG within the Institute of Medicine recommendations. Although the intervention compared to control group was more likely to achieve GWG within recommendations (OR = 1.51; 95% CI (0.81, 2.80)) and total GWG was lower by 1.45 kg (95% CI: (-11.9, 8.88)) neither reached statistical significance. The intervention group achieved significantly higher protein intake at 26-28 week (mean difference (MD); 15.0 g/day; 95% CI (8.1, 21.9)) and 36-38 week gestation (MD = 15.2 g/day; 95% CI (9.4, 21.1)) and higher healthy diet scores (22.5 ± 6.9 vs. 18.7 ± 8.5, p < 0.005) but step counts were similar averaging 6335 steps/day. Pregnancy and infant birth outcomes were similar between groups. While the structured and monitored nutrition with counselling improved diet quality and protein intake and may have benefited GWG, the exercise goal of 10,000 steps/day was unachievable. The results can inform future recommendations for diet and physical activity in pregnancy.

Assessing food and nutrition literacy in children and adolescents: a systematic review of existing tools.

OBJECTIVE: Food literacy (FL) and nutrition literacy (NL) are concepts that can help individuals to navigate the current food environment. Building these skills and knowledge at a young age is important for skill retention, confidence in food practices and supporting lifelong healthy eating habits. The objectives of this systematic review were to: (i) identify existing tools that measure FL and NL among children and/or adolescents and (ii) describe the psychometric properties. DESIGN: A 4-phase protocol was used to systematically retrieve articles. The search was performed in May 2021. Study characteristics and psychometric properties were extracted, and a narrative synthesis was used to summarise findings. Risk of bias was assessed using the COSMIN checklist. SETTING: Six databases were searched to identify current tools. PARTICIPANTS: Children (2-12 years) and adolescents (13-18 years) participated in this study. RESULTS: Twelve tools were identified. Three tools measured FL, 1 tool measured NL, 4 tools measured both FL and NL, and 4 tools measured subareas of NL-more specifically, critical NL, food label and menu board literacy. Most tools were self-reported, developed based on a theoretical framework and assessed some components of validity and/or reliability for a specific age and ethnic group. The majority of tools targeted older children and adolescents (9-18 years of age), and one tool targeted preschoolers (3-6 years of age). CONCLUSIONS: Most widely used definitions of FL and NL do not acknowledge life-stage specific criterion. Continued efforts are needed to develop a comprehensive definition and framework of FL and NL appropriate for children, which will help inform future assessment tools.

Maternal pregnancy diet, postnatal home environment and executive function and behavior in 3- to 4-y-olds.

BACKGROUND: Optimal maternal nutrition during pregnancy has been linked to better cognitive and behavioral development in children. However, its influence on the effects of suboptimal postnatal exposures like reduced stimulation and support in the home is not known. OBJECTIVES: To examine the effect of maternal pregnancy diet on executive function and/or behavioral development in children raised in suboptimal home environments. METHODS: Data were provided by 808 mother-infant dyads from the Canadian Maternal-Infant Research on Environmental Chemicals-Child Development study. Maternal pregnancy diet was self-reported using the Healthy Eating Index 2010 questionnaire. Stimulation and support in the home was assessed using the Home Observation for Measurement of the Environment (HOME) when children were 3-4 y old. Child executive function was reported by mothers at this age using the Behavior Rating Inventory of Executive Functioning-Preschool Edition, and child behavior was assessed using the Behavior Assessment System for Children-2nd Edition. We examined the interaction of maternal pregnancy diet and postnatal HOME scores on child executive function and behavior using linear regression adjusted for maternal education, postpartum depression, prepregnancy BMI, and smoking. RESULTS: Maternal pregnancy diet was associated with an increasingly positive association with child working memory (ß: 0.21; 95% CI: 0.82, 3.41; P = 0.001), planning (ß: 0.17; 95% CI: 0.38, 2.84; P = 0.007), and adaptability (ß: -0.13; 95% CI: -1.72, -0.08; P = 0.032) as levels of postnatal stimulation decreased. CONCLUSIONS: The positive association of maternal pregnancy diet quality and executive function and adaptability in 3- to 4-y-olds appeared to increase with decreasing levels of postnatal stimulation and support. These results suggest that overall maternal pregnancy diet could be linked to better child neurodevelopment in families experiencing barriers to providing stimulation and support to children in their home.

Diet in Early Pregnancy: Focus on Folate, Vitamin B12, Vitamin D, and Choline.

Purpose: Prenatal multivitamins are recommended in pregnancy. This study assessed food and supplement intakes of folate, vitamin B12 (B12), vitamin D, and choline in pregnant women living in Southern Ontario in comparison with current recommendations. Methods: Women recruited to the Be Healthy in Pregnancy RCT (NCT01693510) completed 3-day diet/supplement records at 12-17 weeks gestation. Intakes of folate, B12, vitamin D, and choline were quantified and compared with recommendations for pregnant women. Results: Folate intake (median (min, max)) was 1963 µg/day dietary folate equivalents (153, 10 846); 90% of women met the Estimated Average Requirement (EAR) but 77% exceeded the Tolerable Upper Intake Level (UL) (n = 232). B12 intake was 12.1 µg/day (0.3, 2336); 96% of women met the EAR with 7% exceeding the EAR 100-fold (n = 232). Vitamin D intake was 564 IU/day (0.0, 11 062); 83% met the EAR, whereas 1.7% exceeded the UL (n = 232). Choline intake was 338 mg/day (120, 1016); only 18% met the Adequate Intake and none exceeded the UL (n = 158). Conclusion: To meet the nutrient requirements of pregnancy many women rely on prenatal vitamins. Reformulating prenatal multivitamin supplements to provide doses of vitamins within recommendations to complement a balanced healthy diet would ensure appropriate micronutrient intakes for pregnant women.

Summer Season and Recommended Vitamin D Intake Support Adequate Vitamin D Status throughout Pregnancy in Healthy Canadian Women and Their Newborns.

BACKGROUND: Vitamin D deficiency in pregnancy is reported as a prevalent public health problem. OBJECTIVES: We aimed to evaluate, in pregnant Canadian women, 1) vitamin D intake, 2) maternal and cord serum 25-hydroxycholecalciferol [25(OH)D] and maternal 1,25-dihydroxycholecalciferol [1,25(OH)2D], and 3) factors associated with maternal serum 25(OH)D. METHODS: Women (n = 187; mean prepregnancy BMI 24.4 kg/m2, mean age 31 y) recruited to the Be Healthy in Pregnancy study provided fasting blood samples and nutrient intake at 12-17 (early) and 36-38 (late) weeks of gestation, and cord blood. Vitamin D intakes (Nutritionist Pro™) and serum 25(OH)D and 1,25(OH)2D concentrations (LC-tandem MS) were measured. RESULTS: Vitamin D intake was comparable in early and late pregnancy [median (IQR) = 586 (459, 859) compared with 689 (544, 974) IU/d; P = 0.83], with 71% consumed as supplements. Serum 25(OH)D was significantly higher in late pregnancy (mean ± SD: 103.1 ± 29.3 nmol/L) than in early pregnancy (82.5 ± 22.5 nmol/L; P < 0.001) and no vitamin D deficiency (<30 nmol/L) occurred. Serum 1,25(OH)2D concentrations were significantly higher in late pregnancy (101.1 ± 26.9 pmol/L) than in early pregnancy (82.2 ± 19.2 pmol/L, P < 0.001, n = 84). Cord serum 25(OH)D concentrations averaged 55% of maternal concentrations. In adjusted multivariate analyses, maternal vitamin D status in early pregnancy was positively associated with summer season (est.ß: 13.07; 95% CI: 5.46, 20.69; P < 0.001) and supplement intake (est.ß: 0.01; 95% CI: 0.00, 0.01; P < 0.001); and in late pregnancy with summer season (est.ß: 24.4; 95% CI: 15.6, 33.2; P < 0.001), nonmilk dairy intake (est.ß: 0.17; 95% CI: 0.02, 0.32; P = 0.029), and supplement intake (est.ß: 0.01; 95% CI: 0.00, 0.01; P = 0.04). CONCLUSIONS: Summer season and recommended vitamin D intakes supported adequate vitamin D status throughout pregnancy and in cord blood at >50 nmol/L in healthy Canadian pregnant women. This trial was registered at clinicaltrials.gov as NCT01693510.

Maternal and child factors associated with bone length traits in children at 3 years of age.

BACKGROUND: Exposure to sub-optimal maternal vitamin D status during pregnancy has been linked to inadequate in utero bone growth with potential for post-natal deficits, but reported findings are inconsistent. Possible reasons include measurement error in assessing bone length/height, or lack of adjustment for confounding variables such as maternal/infant diet, physical activity and season of birth. The objective of this study was to determine the maternal and child factors associated with bone length traits in children at 3 years of age as part of a longitudinal follow-up of a pregnancy cohort. METHODS: Mother-child dyads enrolled in the Family Atherosclerosis Monitoring In early Life study were included. Maternal serum 25-hydroxyvitamin D (25(OH)D) concentration was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Anthropometry, physical activity by questionnaire and dietary assessment by food frequency questionnaire were completed for mothers during pregnancy (27-40 weeks gestation) and for children at 3 years with diet by 3-day food records (Nutritionist Pro). Whole body bone mineral density in mother and child (n = 473) was measured by dual-energy absorptiometry (DXA) at the 3 year visit. A software program was developed using MATLAB to derive bone length measurements from whole body DXA images using 8 long bones of each child. Association between maternal and child variables with offspring bone length was assessed using unadjusted and adjusted multivariate linear regression analyses. RESULTS: In the final adjusted multivariate regression model, factors associated with child bone length were maternal height (p = 0.05), child birth length (p = 0.005) and child weight z-score at 3 years (p < 0.001). No association was observed between maternal serum 25(OH)D concentrations in pregnancy (of which 77% were in normal range) and child bone length. CONCLUSION: In healthy Canadian mothers and their children, the factors associated with child bone length achieved at 3 years of age appear to be related to genetic traits rather than environmental exposures. Measures of the length of long bones in children using DXA scans may have provided a more accurate assessment of bone length than whole body height measures.

Factors Associated with Serum 25-Hydroxyvitamin D Concentration in Two Cohorts of Pregnant Women in Southern Ontario, Canada.

Vitamin D deficiency in pregnancy is widely reported, but whether this applies in North America is unclear since no population-based surveys of vitamin D status in pregnancy exist in Canada or the United States. The objectives were to assess (i) the intake and sources of vitamin D, (ii) vitamin D status, and (iii) factors associated with serum 25-hydroxyvitamin D (25-OHD) concentration in two cohorts of pregnant women from Southern Ontario, Canada, studied over a span of 14 years. Maternal characteristics, physical measurements, fasting blood samples and nutrient intake were obtained at enrolment in 332 pregnant women from the Family Atherosclerosis Monitoring In early Life (FAMILY) study and 191 from the Be Healthy in Pregnancy (BHIP) study. Serum 25-OHD was measured by LC/MS-MS. The median (Q1, Q3) total vitamin D intake was 383 IU/day (327, 551) in the FAMILY study and 554 IU/day (437, 796) in the BHIP study. Supplemental vitamin D represented 64% of total intake in participants in FAMILY and 78% in BHIP. The mean (SD) serum 25-OHD was 76.5 (32.9) nmol/L in FAMILY and 79.7 (22.3) nmol/L in BHIP. Being of European descent and blood sampling in the summer season were significantly associated with a higher maternal serum 25-OHD concentration. In summary, health care practitioners should be aware that vitamin D status is sufficient in the majority of pregnant Canadian women of European ancestry, likely due to sun exposure.

Structured diet and exercise guidance in pregnancy to improve health in women and their offspring: study protocol for the Be Healthy in Pregnancy (BHIP) randomized controlled trial.

BACKGROUND: Evidence from epidemiological and animal studies support the concept of programming fetal, neonatal, and adult health in response to in utero exposures such as maternal obesity and lifestyle variables. Excess gestational weight gain (GWG), maternal physical activity, and sub-optimal and excess nutrition during pregnancy may program the offspring's risk of obesity. Maternal intake of dairy foods rich in high-quality proteins, calcium, and vitamin D may influence later bone health status. Current clinical practice guidelines for managing GWG are not founded on randomized trials and lack specific "active intervention ingredients." The Be Healthy in Pregnancy (BHIP) study is a randomized controlled trial (RCT) designed to test the effectiveness of a novel structured and monitored Nutrition + Exercise intervention in pregnant women of all pre-pregnancy weight categories (except extreme obesity), delivered through prenatal care in community settings (rather than in hospital settings), on the likelihood of women achieving recommended GWG and a benefit to bone status of offspring and mother at birth and six months postpartum. METHODS: The BHIP study is a two-site RCT that will recruit up to 242 participants aged > 18 years at 12-17 weeks of gestation. After baseline measures, participants are randomized to either a structured and monitored Nutrition + Exercise (intervention) or usual care (control) program for the duration of their pregnancy. The primary outcome of the study is the percent of women who achieve GWG within the Institute of Medicine (IOM) guidelines. The secondary outcomes include: (1) maternal bone status via blood bone biomarkers during pregnancy; (2) infant bone status in cord blood; (3) mother and infant bone status measured by dual-energy absorptiometry scanning (DXA scan) at six months postpartum; (4) other measures including maternal blood pressure, blood glucose and lipid profiles, % body fat, and postpartum weight retention; and (5) infant weight z-scores and fat mass at six months of age. DISCUSSION: If effective, this RCT will generate high-quality evidence to refine the nutrition guidelines during pregnancy to improve the likelihood of women achieving recommended GWG. It will also demonstrate the importance of early nutrition on bone health in the offspring. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01689961 Registered on 21 September 2012.

Validation of a Food Frequency Questionnaire for Bone Nutrients in Pregnant Women.

PURPOSE: The aim was to validate a food frequency questionnaire (FFQ) against a 3-day food record (3DFR) for pregnant women with a focus on nutrients important for bone health from food and supplements. METHODS: The FFQ and 3DFR were administered to pregnant women (n = 42) aged 18-45 years in their third trimester of pregnancy in Hamilton, Ontario. Nutrient analysis of intakes was conducted using an FFQ calculator and Nutritionist-Pro software. The average daily serving consumption of Milk and alternatives group and Vegetable subgroup from Canada's Food Guide were also compared. RESULTS: There was a high positive correlation between methods for total dietary vitamin D (r = 0.83). Low positive associations were observed for total protein (r = 0.37), calcium (r = 0.36), vitamin K (r = 0.41), and servings of Milk and alternatives (r = 0.36). A cross-classification analysis using participants' intake quartiles revealed no major misclassifications. Bland-Altman analysis showed that the FFQ mildly underestimated the intake for protein, whereas it grossly overestimated the intake of vitamin K, and daily servings of Milk and alternatives and Vegetable. CONCLUSIONS: This FFQ can serve as a useful tool in clinical and research settings to assess key bone nutrients from foods and supplement sources in pregnant women.

Metabolomics Reveals Metabolically Healthy and Unhealthy Obese Individuals Differ in their Response to a Caloric Challenge.

OBJECTIVE: To determine if metabolically healthy obese (MHO) individuals have a different metabolic response to a standardized diet compared to lean healthy (LH) and metabolically unhealthy obese (MUO) individuals. METHODS: Thirty adults (35-70 yrs) were classified as LH, MHO, and MUO according to anthropometric and clinical measurements. Participants consumed a standardized high calorie meal (~1330 kcal). Blood glucose and insulin were measured at fasting, and 15, 30, 60, 90 and 120 min postprandially. Additional blood samples were collected for the targeted analysis of amino acids (AAs) and derivatives, and fatty acids (FAs). RESULTS: The postprandial response (i.e., area under the curve, AUC) for serum glucose and insulin were similar between MHO and LH individuals, and significantly lower than MUO individuals (p < 0.05). Minor differences were found in postprandial responses for AAs between MHO and MUO individuals, while three polyunsaturated FAs (linoleic acid, γ-linolenic acid, arachidonic acid) showed smaller changes in serum after the meal in MHO individuals compared to MUO. Fasting levels for various AAs (notably branched-chain AA) and FAs (e.g., saturated myristic and palmitic acids) were found to correlate with glucose and insulin AUC. CONCLUSION: MHO individuals show preserved insulin sensitivity and a greater ability to adapt to a caloric challenge compared to MUO individuals.

Molecular insights into the role of white adipose tissue in metabolically unhealthy normal weight and metabolically healthy obese individuals.

Obesity is a risk factor for the development of type 2 diabetes and cardiovascular disease. However, it is now recognized that a subset of individuals have reduced cardiometabolic risk despite being obese. Paradoxically, a subset of lean individuals is reported to have high risk for cardiometabolic complications. These distinct subgroups of individuals are referred to as metabolically unhealthy normal weight (MUNW) and metabolically healthy obese (MHO). Although the clinical relevance of these subgroups remains debated, evidence shows a critical role for white adipose tissue (WAT) function in the development of these phenotypes. The goal of this review is to provide an overview of our current state of knowledge regarding the molecular and metabolic characteristics of WAT associated with MUNW and MHO. In particular, we discuss the link between different WAT depots, immune cell infiltration, and adipokine production with MUNW and MHO. Furthermore, we also highlight recent molecular insights made with genomic technologies showing that processes such as oxidative phosphorylation, branched-chain amino acid catabolism, and fatty acid ß-oxidation differ between these phenotypes. This review provides evidence that WAT function is closely linked with cardiometabolic risk independent of obesity and thus contributes to the development of MUNW and MHO.

Serum and adipose tissue amino acid homeostasis in the metabolically healthy obese.

A subgroup of obese individuals, referred to as metabolically healthy obese (MHO), have preserved insulin sensitivity and a normal lipid profile despite being obese. The molecular basis for this improved cardiometabolic profile remains unclear. Our objective was to integrate metabolite and gene expression profiling to elucidate the molecular distinctions between MHO and metabolically unhealthy obese (MUO) phenotypes. A subset of individuals were selected from the Diabetes Risk Assessment study and classified into three groups using anthropometric and clinical measurements: lean healthy (LH), MHO, and MUO. Serum metabolites were profiled using gas chromatography coupled to mass spectrometry. Multivariate data analysis uncovered metabolites that differed between groups, and these were subsequently validated by capillary electrophoresis coupled to mass spectrometry. Subcutaneous adipose tissue (SAT) gene expression profiling using microarrays was performed in parallel. Amino acids were the most relevant class of metabolites distinguishing MHO from MUO individuals. Serum levels of glutamic acid, valine, and isoleucine were positively associated (i.e., LH < MHO < MUO) with homeostasis model assessment-insulin resistance (HOMA-IR) and glycated hemoglobin (HbA1c) values, while leucine was only correlated with HOMA-IR. The glutamine-to-glutamic acid ratio and glycine were inversely correlated (i.e., LH > MHO > MUO) with HbA1c values. Concomitantly, SAT gene expression profiling revealed that genes related to branched-chain amino acid catabolism and the tricarboxylic acid cycle were less down-regulated in MHO individuals compared to MUO individuals. Together, this integrated analysis revealed that MHO individuals have an intermediate amino acid homeostasis compared to LH and MUO individuals.

A distinct fatty acid profile underlies the reduced inflammatory state of metabolically healthy obese individuals.

BACKGROUND: Obesity is associated with numerous health complications; however, a subgroup of obese individuals (termed the metabolically healthy obese or MHO) appear to have lower risk for complications such as type 2 diabetes and cardiovascular disease. Emerging evidence suggests that MHO individuals have reduced inflammation compared to their metabolically unhealthy obese (MUO) counterparts. As it is recognized that fatty acids (FAs) have a strong relationship with inflammation, the current study aimed to uncover if the reduced inflammation observed in MHO individuals is mirrored by a more favourable FA profile. METHODS: Fasted serum samples were collected from lean healthy (LH), MHO, and MUO participants (n = 10/group) recruited from the Diabetes Risk Assessment study. A panel of pro- and anti-inflammatory markers were measured by immunoassay. Total serum FA profiling, as well as the FA composition of circulating phospholipids (PL) and triglycerides (TG), was measured by gas chromatography. ANOVA and Mann-Whitney-Wilcoxon tests were used to assess statistical significance between the groups (P<0.05). RESULTS: MHO and MUO individuals had similar BMI and body fat %; however, lipid parameters in MHO individuals more closely resembled that of LH individuals. MHO individuals had circulating levels of high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) similar to LH individuals, while levels of platelet derived growth factor-ßß (PDGF-ßß) were intermediate to that of LH and MUO individuals. FA profiling analysis combined with discriminant analysis modelling highlighted a panel of nine FAs (consisting of three saturated, three monounsaturated, and three polyunsaturated FAs) in PL and TG fractions that distinguished the three groups. Specifically, saturated FA (myristic and stearic acids) levels in MHO individuals resembled that of LH individuals. CONCLUSION: Our results suggest that the reduced inflammatory state of MHO individuals compared to MUO individuals may stem, in part, from a more favourable underlying FA profile.

Plasma levels of 14:0, 16:0, 16:1n-7, and 20:3n-6 are positively associated, but 18:0 and 18:2n-6 are inversely associated with markers of inflammation in young healthy adults.

Inflammation is a recognized risk factor for the development of chronic diseases, such as type 2 diabetes and atherosclerosis. Evidence suggests that individual fatty acids (FA) may have distinct influences on inflammatory processes. The goal of this study was to conduct a cross-sectional analysis to examine the associations between circulating FA and markers of inflammation in a population of young healthy Canadian adults. FA, high-sensitivity C-reactive protein (hsCRP), and cytokines were measured in fasted plasma samples from 965 young adults (22.6 ± 0.1 years). Gas chromatography was used to measure FA. The following cytokines were analyzed with a multiplex assay: regulated upon activation normal T cell expressed and secreted (RANTES/CCL5), interleukin 1-receptor antagonist (IL-1Ra), interferon-γ (IFN-γ), interferon-γ inducible protein 10 (IP-10), and platelet-derived growth factor ß (PDGF-ßß). Numerous statistically significant associations (p < 0.05, corrected for multiple testing) were identified between individual FA and markers of inflammation using linear regression. Myristic (14:0), palmitic (16:0), palmitoleic (16:1n-7), and dihomo-γ-linolenic (20:3n-6) acids were positively associated with all markers of inflammation. In contrast, stearic acid (18:0) was inversely associated with hsCRP and RANTES, and linoleic acid (18:2n-6) was inversely associated with hsCRP, RANTES and PDGF-ßß. In conclusion, our results indicate that specific FA are distinctly correlated with various markers of inflammation. Moreover, the findings of this study suggest that FA profiles in young adults may serve as an early indicator for the development of future complications comprising an inflammatory component.

Fish oil supplementation alters circulating eicosanoid concentrations in young healthy men.

OBJECTIVE: Increasing omega-3 fatty acid (FA) intake, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is associated with numerous health benefits; however, the benefits on inflammation appear to vary depending on the study population examined. While improvements in inflammatory status have been reported in the elderly, there is less evidence regarding the effects of fish oil supplementation on inflammation in young adults. The goal of the present study was to examine the influence of fish oil supplementation on lipid metabolites and the inflammatory status of young healthy men. MATERIALS/METHODS: Fasted serum samples were collected from 10 young healthy males (23.4 ± 1.7 years) before and after a 3-month supplementation of fish-oil containing 2.0g EPA and 1.0g DHA. Samples were analyzed to investigate changes in FA profiles, bioclinical parameters (e.g. triglyceride and hs-CRP), and a panel of 26 eicosanoids. Paired t-tests were used to evaluate changes between the time points. RESULTS: Serum triglycerides decreased (P=0.0006) while the proportion of HDL-c (relative to total cholesterol) increased significantly (P=0.0495) after fish oil supplementation. Specific monounsaturated and polyunsaturated FA levels were changed following supplementation, including reductions in palmitoleic and oleic acid, and, as expected, increases in EPA and DHA. We also observed increases in eicosanoids, namely prostaglandin-F2α (P<0.0001) and thromboxane-B2 (P=0.0296), after fish oil supplementation. CONCLUSIONS: A 3-month fish oil supplementation in young healthy men improved circulating triglyceride levels and the HDL-c ratio while, concomitantly, increasing the concentrations of two eicosanoids (prostaglandin-F2α and thromboxane-B2). This suggests that fish oil supplementation does have significant benefits in young healthy adults and that specific omega-6-derived eicosanoids can help to further our understanding regarding the beneficial link between omega-3 FA and inflammation.