Unexpected effects of urban food activism on community and human wellbeing.

Participation in urban agriculture conducted through community gardens and allotments is known for its benefits to physical and mental health. Due to the recognition of these benefits, which include reduction of stress, depression and anxiety, such participation is increasingly being prescribed as a non-medical health intervention. Community gardens have the added advantage of immersion into a community, without the often-long waiting lists and level of commitment involved in allotment tenancies. What has not been explored is the demanding nature of the commitment required by volunteer coordinators, and ironically, the negative effects it can have on their wellbeing. In a study of food activism in Aberdeen, UK, we conducted 21 semi-structured interviews with participants from a range of bodies involved in the city's food growing projects. From the spectrum of food growers, we found that volunteer coordinators of community gardens experienced the greatest burdens on their time and wellbeing, with their demanding multi-functional roles leading to fatigue and feelings of over-commitment. Other problems encountered by community gardeners were over-reliance on grant funding and the disproportionate impacts of COVID closures on vulnerable groups. Policy interventions are required to reduce dependency on competitive grant funding and to support both coordinators and the long-term sustainability of community gardens.

A mediation analysis on the relationship between dietary glycemic load, obesity and cardiovascular risk factors in children.

BACKGROUND/OBJECTIVE: Adiposity may mediate the effect of dietary glycemic load (GL) on lipid profiles in children, as studies have shown an association between dietary GL and adiposity and between adiposity and lipid profiles. Our objective was to evaluate the role of adiposity as a mediator in the association between dietary GL and lipid profiles after 2 years. SUBJECTS/METHODS: The Quebec Adipose and Lifestyle InvesTigation in Youth study included 630 children, 8-10 years old at recruitment with at least one parent with overweight or obesity with 2-year follow-up. Three baseline 24-h dietary recalls were administered by a dietitian at baseline. Child and parent characteristics were obtained through direct measurement (blood lipids, anthropometrics) or questionnaires (socio-economic characteristics). Indicators of adiposity, including body mass index (BMI) z-score and percent body fat, were the mediators of interest. A conventional approach using the Baron and Kenny method was used. A causal approach using marginal structural models (MSM) was used to estimate the controlled direct effect. RESULTS: Mean age at baseline was 9.6 years and 33% were overweight or obese. Both methods revealed that the effect of GL on blood lipids was mediated by adiposity. The weighted MSM did not show evidence of a direct effect (TG: ß =;0.01, 95% CI = -0.01,0.02; HDL: ß = 0.005, 95%CI = -0.002,0.01), whereas the conventional method did for TG but not HDL (TG:ß = 0.04, 95%CI = 0.01,0.07; HDL: ß = -0.01, 95%CI = -0.03,0.01). CONCLUSION: Adiposity contributes substantially to the association between GL and blood lipids. The choice of approach for mediation analysis should be based on the fulfilment of conditions of each method.

Reproducibility and sensitivity of 36 methods to quantify the SARS-CoV-2 genetic signal in raw wastewater: findings from an interlaboratory methods evaluation in the U.S.

In response to COVID-19, the international water community rapidly developed methods to quantify the SARS-CoV-2 genetic signal in untreated wastewater. Wastewater surveillance using such methods has the potential to complement clinical testing in assessing community health. This interlaboratory assessment evaluated the reproducibility and sensitivity of 36 standard operating procedures (SOPs), divided into eight method groups based on sample concentration approach and whether solids were removed. Two raw wastewater samples were collected in August 2020, amended with a matrix spike (betacoronavirus OC43), and distributed to 32 laboratories across the U.S. Replicate samples analyzed in accordance with the project's quality assurance plan showed high reproducibility across the 36 SOPs: 80% of the recovery-corrected results fell within a band of ±1.15 log10 genome copies per L with higher reproducibility observed within a single SOP (standard deviation of 0.13 log10). The inclusion of a solids removal step and the selection of a concentration method did not show a clear, systematic impact on the recovery-corrected results. Other methodological variations (e.g., pasteurization, primer set selection, and use of RT-qPCR or RT-dPCR platforms) generally resulted in small differences compared to other sources of variability. These findings suggest that a variety of methods are capable of producing reproducible results, though the same SOP or laboratory should be selected to track SARS-CoV-2 trends at a given facility. The methods showed a 7 log10 range of recovery efficiency and limit of detection highlighting the importance of recovery correction and the need to consider method sensitivity when selecting methods for wastewater surveillance.

Food Insecurity Is Linked to Dietary Intake but Not Growth of Children in the Caribbean

ABSTRACT Objective: To examine food insecurity and its relationship with children's nutritional health. Methods: The data for the 390 children, aged 7-12 years and their caregivers, recruited from eight schools in Trinidad and seven schools in St. Kitts in 2013-2014 from a study dealing with food and nutrition security were used for this study. Food insecurity was assessed using the USDA's Household Food Security Survey Module, and 24-hour dietary recall of the children was assessed in home interviews. The children's height and weight were measured, and a capillary blood sample was collected at their schools. Results: Overall, 41.5% of the caregivers reported household food insecurity, with 15% of the children living in households with very low food security. Daily intakes of protein and zinc were higher among the children from the 'food secure' vs the 'food insecure' households (protein, 59.6 ± 31.5 g vs 50.9 ± 24.4 g, p = 0.003; zinc, 7.33 ± 5.02 mg vs 6.20 ± 3.47 mg, p = 0.004, respectively). There were no other differences in their dietary intake. The children's body mass index z-score, weight status and height-for-age z-score were not associated with their food security status, and there was no evidence of stunting in either group. Anaemia, however, was prevalent (30%) and higher among the children from the food insecure households (39% vs 23%; p = 0.002). Conclusion: Household food insecurity was was associated with lower intakes of some nutrients, and anaemia rates were higher among the children living in food insecure households but food insecurity was not related to the indicators of growth or weight status.

Effects of dietary glycemic index and load on children's cardiovascular risk factors.

PURPOSE: Consumption of foods high in glycemic index (GI) and glycemic load (GL) is associated with cardiovascular (CV) diseases in adulthood. We examined whether GI and GL predict CV risk factors in children after 2 years of follow-up. METHODS: Three 24-hour recalls were administered at baseline, and individual average daily GI and GL scores were calculated in a cohort of 8-10 year-old children. CV risk factors included body mass index z-score (BMIz), percent fat mass, triglycerides (TGs), low-density lipoprotein and high-density lipoprotein (HDL) cholesterol, and systolic and diastolic blood pressure. Main analyses consisted of multiple linear regression adjusted for anthropometric, socioeconomic, and dietary factors. RESULTS: After 2 years, the highest dietary GL tertile compared with the lowest was associated with increased BMIz (mean difference [MD], 1.1; 95% CI, 0.88-1.31), fat mass (MD, 10.8%; 95% CI, 8.62-13.0), TGs (MD, 0.17 mmol/L; 95% CI, 0.07-0.28), and decreased HDL (MD, -0.13 mmol/L; 95% CI, -0.19 to -0.07). The GL-TG and the GL-HDL associations were mediated by BMIz. CONCLUSIONS: GL predicts increased BMIz, percent fat mass, and TGs and decreased HDL in young children after 2 years. Recommendations to decrease CV risk in children should include lowering foods high in GL.

The Cardiometabolic Risk Profile of Underreporters of Energy Intake Differs from That of Adequate Reporters among Children at Risk of Obesity.

Background: Misreporting of energy intake (EI) in nutritional epidemiology is a concern because of information bias, and tends to occur differentially in obese compared with nonobese subjects. Objective: We examined characteristics of misreporters within a cohort of children with a parental history of obesity and the bias introduced by underreporting. Methods: The QUebec Adipose and Lifestyle InvesTigation in Youth (QUALITY) cohort included 630 Caucasian children aged 8-10 y at recruitment with ≥1 obese parent [body mass index (BMI; in kg/m2) >30 or waist circumference >102 cm (men), >88 cm (women)] and free of diabetes or severe illness. Children on antihypertensive medications or following a restricted diet were excluded. Child and parent characteristics were measured directly or by questionnaire. Three 24-h dietary recalls were administered by phone by a dietitian. Goldberg's cutoff method identified underreporters (URs). Logistic regression identified correlates of URs. We compared coefficients from linear regressions of BMI after 2 y on total EI at baseline 1) in all participants; 2) in adequate reporters (ARs) (excluding URs); 3) in all participants statistically adjusted for underreporting; 4) excluding URs using individual physical activity level (PAL)-specific cutoffs; and 5) in all participants statistically adjusted for underreporting using PAL-specific cutoffs. Results: We identified 175 URs based on a calculated cutoff of 1.11. URs were older, had a higher BMI z score, and had poorer cardiometabolic health indicators. Parents of URs had a lower family income and higher BMI. Child BMI z score (OR: 3.07; 95% CI: 2.38, 3.97) and age (OR: 1.46/y; 95% CI: 1.14, 1.87/y) were the strongest correlates of underreporting. The association between BMI and total EI was null in all participants but became significantly positive after excluding URs (ß = 0.62/1000 kcal; 95% CI: 0.33, 0.92/1000 kcal) and after adjustment for URs (ß = 0.85/1000 kcal; 95% CI: 0.55, 1.06/1000 kcal). Conclusions: URs in 8- to 10-y-old children differed from ARs. Underreporting biases measurement of nutritional exposures and the assessment of exposure-outcome relations. Identifying URs and using an appropriate correction method is essential.

Understanding how Indigenous culturally-based interventions can improve participants' health in Canada.

There is increasing recognition that culturally-based diabetes prevention programs can facilitate the adoption and maintenance of healthy behaviours in the communities in which they are implemented. The Kahnawake School Diabetes Prevention Project (KSDPP) is a health promotion, community-based participatory research project aiming to reduce the incidence of Type 2 diabetes in the community of Kahnawake (Mohawk territory, Canada), with a large range of interventions integrating a Haudenosaunee perspective of health. Building on a qualitative, naturalistic and interpretative inquiry, this study aimed to assess the outcomes of a suite of culturally-based interventions on participants' life and experience of health. Data were collected through semi-structured qualitative interviews of 1 key informant and 17 adult, female Kahnawake community members who participated in KSDPP's suite of interventions from 2007 to 2010. Grounded theory was chosen as an analytical strategy. A theoretical framework that covered the experiences of all study participants was developed from the grounded theory analysis. KSDPP's suite of interventions provided opportunities for participants to experience five different change processes: (i) Learning traditional cooking and healthy eating; (ii) Learning physical activity; (iii) Learning mind focusing and breathing techniques; (iv) Learning cultural traditions and spirituality; (v) Socializing and interacting with other participants during activities. These processes improved participants' health in four aspects: mental, physical, spiritual and social. Results of this study show how culturally-based health promotion can bring about healthy changes addressing the mental, physical, spiritual and social dimensions of a holistic concept of health, relevant to the Indigenous perspective of well-being.

Rapid increase of overweight and obesity among primary school-aged children in the Caribbean; high initial BMI is the most significant predictor.

BACKGROUND: To examine predictors of increasing overweight among children in two developing countries. METHODS: Primary school children (6-10 y at baseline, n = 336) and their caregivers.Longitudinal data were collected in 2012, with follow-up 18 months later. Data on children's height, weight and dietary intake were collected within 8 primary public schools in Trinidad and 7 schools in St. Kitts. Caregivers' demographic and anthropometric data were also collected. RESULTS: At baseline, children's age and sex and caregivers' BMI, age, and marital status and reported dietary intake were similar across all weight groups. The incidence of overweight and obesity among children was 8.8% and 8.1%, respectively. Dietary intake at baseline was not related to becoming overweight or obese. Similarly there were no differences in reported intake among children who became overweight or obese except that they consumed fewer fruits (0.54±0.92 vs. 0.98±1.66, p = 0.017). Misreporting of energy intake was higher among overweight/obese children as compared to those who were not overweight/obese (27% vs. 17%, p = 0.047). The baseline predictors of increasing BMI (adjusted) of the children were older age, higher baseline BMI z-score and higher height-for-age (HFA) z-score; caregiver BMI, children's energy intake (with adjustment for misreporting) did not predict changes in children's BMI. CONCLUSIONS: The increasing prevalence of overweight/obesity among children is a serious problem in the Caribbean. Heavier children are at elevated risk of continued rapid increase in their weight status, pointing to the need for early intervention.

Reliability of length measurements collected by community nurses and health volunteers in rural growth monitoring and promotion services.

BACKGROUND: Length measurements are important in growth, monitoring and promotion (GMP) for the surveillance of a child's weight-for-length and length-for-age. These two indices provide an indication of a child's risk of becoming wasted or stunted, and are more informative about a child's growth than the widely used weight-for-age index (underweight). Although the introduction of length measurements in GMP is recommended by the World Health Organization, concerns about the reliability of length measurements collected in rural outreach settings have been expressed by stakeholders. Our aim was to describe the reliability and challenges associated with community health personnel measuring length for rural outreach GMP activities. METHODS: Two reliability studies (A and B), using 10 children less than 24 months each, were conducted in the GMP services of a rural district in Ghana. Fifteen nurses and 15 health volunteers (HV) with no prior experience in length measurements were trained. Intra- and inter-observer technical error of measurement (TEM), average bias from expert anthropometrist, and coefficient of reliability (R) of length measurements were assessed and compared across sessions. Observations and interviews were used to understand the ability and experiences of health personnel with measuring length at outreach GMP. RESULTS: Inter-observer TEM was larger than intra-observer TEM for both nurses and HV at both sessions and was unacceptably (compared to error standards) high in both groups at both time points. Average biases from expert's measurements were within acceptable limits, however, both groups tended to underestimate length measurements. The R for lengths collected by nurses (92.3%) was higher at session B compared to that of HV (87.5%). Length measurements taken by nurses and HV, and those taken by an experienced anthropometrist at GMP sessions were of moderate agreement (kappa = 0.53, p < 0.0001). CONCLUSIONS: The reliability of length measurements improved after two refresher trainings for nurses but not for HV. In addition, length measurements taken during GMP sessions may be susceptible to errors due to overburdened health personnel and crowded GMP clinics. There is need for both pre- and in-service training of nurses and HV on length measurements and procedures to improve reliability of length measurements.

A prospective evaluation of the depression-nutrient intake reverse causality hypothesis in a cohort of community-dwelling older Canadians.

Studies have investigated the potential protective effects that diet may have on late-life depression incidence. This disorder can, however, affect the person's food intake, widely known as the reverse causality hypothesis of depression. To test this hypothesis, we compared mean nutrient intakes from three 24-h recalls during the year depression was detected (Geriatric Depression Scale ≥11 or antidepressant medication) with intakes from 1 year earlier among community-dwelling older adults (67-83 years) followed up annually in the 4-year Québec Longitudinal Study on Nutrition and Aging, who were free of depression and cognitive impairment at baseline. Participants (n 158, 64·4 % female) who became depressed and had data available for all follow-up years were matched by age group and sex with non-depressed participants. General linear mixed models were adjusted for percentage changes in physical activity, functional autonomy and stressful life events reported at the time of positive screening. A significant group effect for the dietary intake of all three B-vitamins was observed, as depression cases had consistently lower dietary intakes than controls (P<0·01). Over time, intakes of dietary vitamin B12 declined within depressed participants in bivariate analysis, but there was no time×group effect for any nutrient tested in the multivariate analyses. Intakes of energy, protein, saturated fat and total dietary fibre did not change in cases v. CONTROLS: Among community-dwelling older adults, declines in dietary vitamins B6, B12 and folate may precede depression incidence. To help preventative efforts by programmes and practitioners, longitudinal cohorts of longer duration should investigate the extent of the decline in dietary intakes relative to the time of depression.

School food environments associated with adiposity in Canadian children.

BACKGROUND/OBJECTIVES: Targeting obesogenic features of children's environment that are amenable to change represents a promising strategy for health promotion. The school food environment, defined as the services and policies regarding nutrition and the availability of food in the school and surrounding neighborhood, is particularly important given that students travel through the school neighborhood almost daily and that they consume a substantial proportion of their calories at school. SUBJECTS/METHODS: As part of the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort study, we assessed features of school indoor dietary environment and the surrounding school neighborhoods, when children were aged 8-10 years (2005-2008). School principals reported on food practices and policies within the schools. The density of convenience stores and fast-food outlets surrounding the school was computed using a Geographical Information System. Indicators of school neighborhood deprivation were derived from census data. Adiposity outcomes were measured in a clinical setting 2 years later, when participants were aged 10-12 years (2008-2011). We conducted cluster analyses to identify school food environment types. Associations between school types and adiposity were estimated in linear regression models. RESULTS: Cluster analysis identified three school types with distinct food environments. Schools were characterized as: overall healthful (45%); a healthful food environment in the surrounding neighborhood, but an unhealthful indoor food environment (22%); or overall unhealthful (33%). Less healthful schools were located in more deprived neighborhoods and were associated with greater child adiposity. CONCLUSIONS: Despite regulatory efforts to improve school food environments, there is substantial inequity in dietary environments across schools. Ensuring healthful indoor and outdoor food environments across schools should be included in comprehensive efforts to reduce obesity-related health disparities.

Diet quality as measured by the Diet Quality Index-International is associated with prospective changes in body fat among Canadian children.

OBJECTIVE: To quantify the association of dietary quality with prospective changes in adiposity. DESIGN: Children participating in the QUALITY (QUebec Adipose and Lifestyle InvesTigation in Youth) study underwent examination at baseline and at 2-year follow-up. Dietary quality was assessed by the Diet Quality Index-International (DQII) using three non-consecutive 24 h diet recalls at baseline. The DQII has four main categories: dietary adequacy, variety, moderation and overall balance. Fat mass index (FMI; [fat mass (kg)]/[height (m)]2), central FMI (CFMI; [trunk fat mass (kg)]/[height (m)]2), percentage body fat (%BF; [total fat mass (kg)]/[total mass (kg)]) and percentage central BF (%CBF; [trunk fat mass (kg)]/[total mass (kg)]) were assessed through dual-energy X-ray absorptiometry. SETTING: Children were selected from schools in the greater Montreal, Sherbrooke and Quebec City metropolitan areas between 2005 and 2008, Quebec, Canada. SUBJECTS: A total of 546 children aged 8-10 years, including 244 girls and 302 boys. RESULTS: Regression analysis adjusting for age, sex, energy intake, physical activity and Tanner stage revealed that every 10-unit improvement in overall DQII score was associated with lower gain in CFMI (ß=-0·08; 95 % CI -0·17, -0·003) and %BF (ß=-0·55; 95 % CI -1·08, -0·02). Each unit improvement in dietary adequacy score was associated with lower gain in FMI (ß=-0·05; 95 % CI -0·08, -0·008), CFMI (ß=-0·03; 95 % CI -0·05, -0·007), %BF (ß=-0·15; 95 % CI -0·28, -0·03) and %CBF (ß=-0·09; 95 % CI -0·15, -0·02). CONCLUSIONS: Promotion of dietary quality and adequacy may reduce weight gain in childhood and prevent chronic diseases later in life.

Empowering women to breastfeed: Does the Baby Friendly Initiative make a difference?

The Baby-Friendly Hospital Initiative (BFI) is currently presented worldwide as the gold standard model of care for promoting and supporting breastfeeding. However, there is a lack of understanding about the ways in which health services, including the BFI, address the cultural change from a disembodied practice (formula feeding) to an embodied one (breastfeeding) in contexts where formula feeding is the norm. We used a qualitative case study methodology to compare the embodied experience of breastfeeding and the maternal experience of breastfeeding promotion and support services between mothers receiving care from institutions with low and high levels of BFI implementation in Québec, Canada. A total of 11 focus groups were conducted with mothers from six institutions-three with high and three with low levels of BFI implementation. We found the flexible approach to breastfeeding duration, characteristic of BFI services in our study, helped to avoid maternal guilt and shame; the shift to focusing on potential barriers and strategies for overcoming them empowered women to negotiate changes in infant feeding with others and self by addressing the embodied experience of a practice that may not feel natural at the beginning. Findings have implications for the concept of habitus and the construction of the breastfeeding body; we suggest that habitus can change if agents are provided with discursive tools to negotiate this embodied change. Implications for BFI services include the need to implement the 10 steps in a flexible, family-centred way that focuses on empowering women rather than simply reaching outcomes.

Canadian Consensus on Female Nutrition: Adolescence, Reproduction, Menopause, and Beyond.

OBJECTIVES: To provide health care professionals in Canada with the basic knowledge and tools to provide nutrition guidance to women through their lifecycle. OUTCOMES: Optimal nutrition through the female lifecycle was evaluated, with specific focus on adolescence, pre-conception, pregnancy, postpartum, menopause, and beyond. The guideline begins with an overview of guidance for all women, followed by chapters that examine the evidence and provide recommendations for the promotion of healthy nutrition and body weight at each life stage. Nutrients of special concern and other considerations unique to each life stage are discussed in each chapter. EVIDENCE: Published literature, governmental and health agency reports, clinical practice guidelines, grey literature, and textbook sources were used in supporting the recommendations made in this document. VALUES: The quality of evidence was rated using the criteria described in the report of the Canadian Task Force on Preventive Health Care. CHAPTER 2: GENERAL FEMALE NUTRITION: Summary Statements Recommendations CHAPTER 3: ADOLESCENCE NUTRITION: Summary Statements Recommendations CHAPTER 4: PRE-CONCEPTUAL NUTRITION: Summary Statement Recommendations CHAPTER 5: NUTRITION IN PREGNANCY: Summary Statements Recommendations CHAPTER 6: POSTPARTUM NUTRITION AND LACTATION: Summary Statements Recommendations CHAPTER 7: NUTRITION DURING MENOPAUSE AND BEYOND: Summary Statement Recommendations.

Consensus canadien sur la nutrition féminine : adolescence, reproduction, ménopause et au-delà.

OBJECTIFS: Doter les professionnels de la santé du Canada de connaissances et d'outils de base, afin qu'ils puissent prodiguer des conseils nutritionnels aux femmes tout au long de leur cycle de vie. RéSULTATS: L'alimentation optimale a fait l'objet d'une évaluation tout au long du cycle de vie de la femme. Elle a porté en particulier sur l'adolescence, la préconception, la grossesse, la période post-partum, la ménopause et au-delà. Le présent guide fournit d'abord des directives abrégées à l'intention de toutes les femmes. Elles sont suivies de chapitres proposant un examen des données probantes, ainsi que des recommandations sur la promotion d'une alimentation saine et d'un poids santé à chaque étape de la vie. Par ailleurs, tous les chapitres présentent une analyse de nutriments d'intérêt particulier, ainsi que d'autres aspects uniques à chaque étape de la vie. DONNéES PROBANTES: Des documents publiés, des rapports d'organismes gouvernementaux et de santé, des lignes directrices de pratique clinique, de la documentation parallèle et des extraits de manuels ont servi à étayer les recommandations formulées dans le présent document. VALEURS: L'évaluation de la qualité des données probantes repose sur les critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs. CHAPITRE 2 : CONSEILS GéNéRAUX SUR L'ALIMENTATION FéMININE: Déclarations Sommaires Recommandations CHAPITRE 3 : ALIMENTATION DE L'ADOLESCENTE: Déclarations Sommaires Recommandations CHAPITRE 4 : ALIMENTATION PRéCONCEPTIONNELLE: Déclarations Sommaires Recommandations CHAPITRE 5 : ALIMENTATION PENDANT LA GROSSESSE: Déclarations Sommaires Recommandations CHAPITRE 6 : ALIMENTATION ET LACTATION POST-PARTUM: Déclarations Sommaires Recommandations CHAPITRE 7 : ALIMENTATION PENDANT LA MéNOPAUSE ET AU-DELà: Déclarations Sommaires Recommandations.

Relation between mealtime distribution of protein intake and lean mass loss in free-living older adults of the NuAge study.

BACKGROUND: Studies have shown that an even protein intake distribution across meals increased 24-h muscle protein synthesis in young adults compared with a skewed intake. Whether this short-term result translates into long-term preservation of lean mass (LM) in older adults remains unknown. OBJECTIVE: The aim was to examine the extent to which protein quantity and distribution are associated with LM and appendicular LM (aLM), and their 2-y decline, in community-dwelling older adults. DESIGN: Baseline and 2-y follow-up data from 351 men and 361 women (aged 67-84 y) in the NuAge study (Quebec Longitudinal Study on Nutrition as a Determinant of Successful Aging) with available body-composition data (by dual-energy X-ray absorptiometry) were used. Food intake was assessed with the use of three 24-h food recalls collected at baseline and 3 collected at the 2-y follow-up. Protein distribution across meals was calculated as the CV of protein ingested per meal, with lower values reflecting evenness of protein intake. Linear mixed-model analysis was performed to examine changes in LM and aLM across time, by sex, as conditioned by the quantity and distribution of protein intake, adjusted for potential covariates. RESULTS: Over 2 y, LM declined in both men (-2.5% ± 4.0%) and women (-2.0% ± 3.4%) (P < 0.05), whereas aLM loss was not significant (men: -1.5% ± 4.8%; women: -1.2% ± 5.3%; P > 0.05). The decline in LM was not independently affected by the quantity and distribution of protein intake. Yet men and women with evenly distributed protein intakes and men with high protein intakes showed higher LM or aLM throughout the entire follow-up period, even after potential confounders were controlled for (P < 0.05). CONCLUSIONS: Our results suggest that greater protein intakes and a more even distribution across meals are modifiable factors associated with higher muscle mass in older adults but not with losses over 2 y. Interventional studies should determine longer-term effects on preserving LM with aging.

Influence of Adiposity, Physical Activity, Fitness, and Screen Time on Insulin Dynamics Over 2 Years in Children.

IMPORTANCE: Despite extensive evidence showing that lifestyle habits play a critical role in preventing or delaying the onset of type 2 diabetes in adults, little is known regarding the impact of lifestyle habits on type 2 diabetes risk in childhood. OBJECTIVE: To assess whether adiposity, fitness, moderate-to-vigorous physical activity, and screen time predict insulin sensitivity or insulin secretion during a 2-year period in children with a family history of obesity. DESIGN, SETTING, AND PARTICIPANTS: This is a prospective longitudinal cohort study of 630 children, having at least 1 obese parent, recruited from schools in Quebec, Canada, between July 2005 and December 2008 in the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort. Children were assessed at baseline (ages 8-10 years) and 2 years later. Fitness was measured by peak oxygen consumption, percentage of body fat (adiposity) by dual-energy x-ray absorptiometry, moderate-to-vigorous physical activity using accelerometry, and screen time by average daily hours of self-reported television, video game, or computer use. Regression models were adjusted for age, sex, season, and pubertal stage. The current analysis was completed in October 2015. MAIN OUTCOMES AND MEASURES: Insulin sensitivity was measured by the homeostatic model assessment of insulin resistance and an oral glucose tolerance test-based index (Matsuda insulin sensitivity index). Insulin secretion was measured using the area under the curve of insulin to glucose during the first 30 minutes of the oral glucose tolerance test and using the area under the curve of insulin to glucose over 2 hours. RESULTS: Of 630 children evaluated at baseline (mean [SD] age, 9.6 [0.9] years; 54.4% male; 56.2% normal weight, 19.2% overweight, and 22.7% obese), 564 were evaluated at 2-year follow-up. Adiposity and changes in adiposity were the central predictors of insulin dynamics over time. Every additional 1% of body fat at ages 8 to 10 years decreased insulin sensitivity by 2.9% (95% CI, -3.3% to -2.5%; P < .001) and led to a 0.5% (95% CI, 0.09% to 0.8%; P = .02) increased requirement in the area under the curve of insulin to glucose during the first 30 minutes of the oral glucose tolerance test 2 years later. Higher levels of moderate-to-vigorous physical activity and lower screen time appear to be beneficial to insulin sensitivity in part through their effect on adiposity levels. CONCLUSIONS AND RELEVANCE: Adiposity plays a determining role in cardiometabolic health at a young age. Public health strategies that promote healthy body weight, notably physical activity, need to target school-aged and possibly younger children.

Muscle Mass Index and Animal Source of Dietary Protein Are Positively Associated with Insulin Resistance in Participants of the NuAge Study.

OBJECTIVES: Contribute evidence towards the complex interrelationships of body composition, insulin sensitivity and protein intake independently from adiposity in an older population. DESIGN: This is a cross-sectional analysis of an existing dataset in which a literature-supported model linking together the variables of interest is tested using path analysis. SETTING: The loss of muscle mass has been implicated in the development of insulin resistance. We propose to test associations of muscle mass with insulin sensitivity and their respective associations with animal and vegetable sources of protein intake, independently from adiposity. PARTICIPANTS: Non-diabetic participants aged 68-82 years from the NuAge study with all available measures (n=441) were included. MEASUREMENTS: A model considering age, sex, chronic diseases, physical activity; smoking and sources of protein intake influencing body composition components and insulin sensitivity was created and tested with Path Analysis for their independent associations. Muscle mass index (MMI; kg/height in m2) and % body fat were derived from DXA and BIA. Insulin resistance was estimated by the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score and physical activity by the Physical Activity Scale for the Elderly (PASE) questionnaire. Protein intakes were obtained from three non-consecutive 24h-diet recalls. RESULTS: In the final model, direct positive associations were observed between HOMA-IR score and MMI (ß=0.42; 95%CI: 0.24; 0.6) and % body fat (ß=0.094; 95%CI: 0.07; 0.11). There were no direct associations between animal protein intake and MMI or with HOMA-IR. There was a significant direct negative association between plant protein intake and MMI (ß= -0.068; 95%CI: -0.13; -0.003) and significant indirect associations mediated through MMI and % body fat between HOMA-IR and animal protein intake (ß=0.0321; 95%CI: 0.01; 0.05), as well as plant protein intake (ß= -0.07; 95%CI: -0.1; 0.0). CONCLUSIONS: Our final model indicated that MMI and HOMA score were significantly positively associated. Protein intake sources were related to HOMA-IR score differently through MMI and % body fat, respectively.

Intakes of folate, vitamin B6 and B12 and risk of depression in community-dwelling older adults: the Quebec Longitudinal Study on Nutrition and Aging.

BACKGROUND/OBJECTIVES: Depression can decrease quality of life and affect health outcomes in older population. We investigated whether different intake levels of folate, vitamin B6 and B12 were associated with a 3-year depression incidence among generally healthy, community-dwelling older men and women. SUBJECTS/METHODS: Participants in the Québec Longitudinal Study on Nutrition and Aging (NuAge), free of depression (that is, 30-item Geriatric Depression Scale (GDS) <11) at baseline (N=1368; 74 ± 4 years old; 50.5% women), were screened annually for incident depression (GDS ⩾ 11) or antidepressant medication. Tertiles of intakes (food only and food+supplements) were obtained from the mean of three non-consecutive 24-h recalls at baseline. Sex-stratified multiple logistic regression models were adjusted for age, physical activity, physical functioning, stressful life events and total energy intake. RESULTS: Over 3 years, 170 participants were identified as depressed. Women in the highest tertile of B6 intake from food were 43% less likely to become depressed when adjusting for demographic and health factors (multivariate odds ratio (OR) 0.57, 95% confidence interval (CI) 0.39-0.96), but adjustment for energy intake attenuated the effect. Men in the highest tertile of dietary B12 intake had decreased risk of depression (energy-adjusted multivariate OR 0.42, 95% CI 0.20-0.90). No other association was observed. CONCLUSIONS: This study provides some evidence of decreased depression risk among women with higher intakes of vitamin B6 from food, which was dependent on total energy intake, and among men with higher intakes of B12 from food, independently of energy intake.

Predictors of Weight Loss in Young Adults.

BACKGROUND: Increased understanding of weight loss among healthy young people in naturalistic settings could inform the development of effective weight control programs. The aim of this study was to describe loss in BMI over 7 years in a population-based sample of healthy young adolescents (mean age 17 years at beginning of follow-up) and identify determinants of BMI loss. DESIGN AND METHOD: Data were available for 681 participants in the Nicotine Dependence in Teens Study (1999-2012), a longitudinal investigation of adolescents in Montreal (Canada). Loss in BMI was assessed between age 17 and 24 years. Potential predictors of BMI loss including age, sex, mother's education, worry about weight, physical activity, screen time, and cigarette smoking were studied in multivariable logistic regression. RESULTS: Males and females gained 2.0 and 1.4 BMI units, respectively, on average, between age 17 and 24 years. However, 9% of males and 14% of females experienced a loss in BMI ≥1.0 unit. Female sex and a higher BMI at age 17 were associated with a higher probability of BMI loss, but none of age, mother's education, physical activity, screen time, or cigarette smoking were associated with BMI loss between ages 17 and 24. CONCLUSIONS: Whereas BMI increased on average between age 17 and 24 years in a population-based sample of healthy young people, 12% of participants experienced a loss in BMI ≥1 unit. Weight loss was highest among the heaviest persons and did not affect the prevalence of underweight. No single behavior at age 17 stands out as associated with predicting BMI loss.