RESUMEN
Consuming a greater proportion of total energy intake earlier in the day rather than in the evening is proposed to positively influence weight loss and health, potentially due to greater synchronization of human body circadian rhythms. This systematic review provides an update on existing evidence regarding earlier distributed eating patterns in weight loss interventions. Using a robust search strategy in five electronic databases, nine randomized controlled trials investigating the impact of energy intake distribution on weight loss were identified. Following critical appraisal, a random-effects meta-analyses found that, in the context of an energy-reduced diet, distributing energy intake with a focus on earlier intake resulted in significantly greater weight loss (-1.23 kg; 95% CI 2.40, -0.06, p = 0.04). Improvements in HOMA-IR, fasting glucose, and LDL cholesterol were also seen. The current study provides a timely update on the evidence linking distribution of total daily energy intake and health, showing that a focus on earlier intakes can result in greater short-term weight loss compared with later intakes. Future studies are needed to elucidate the impact that earlier intakes may have on weight management and metabolic health.
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Dieta , Ingestión de Energía , Humanos , Ayuno , Conducta Alimentaria , Pérdida de PesoRESUMEN
CONTEXT: Optimizing nutrition in military groups through improved diet quality and nutrition knowledge is key in supporting the high physical and cognitive demands. OBJECTIVE: The objective of this investigation was to systematically review the effectiveness of nutrition interventions among military personnel in improving diet quality and/or nutrition knowledge. DATA SOURCES: Medline, Embase, CINAHL, and Scopus were searched from the earliest records to May 2020. DATA EXTRACTION: Data were extracted by 2 reviewers. The primary outcomes were diet quality and/or nutrition knowledge. DATA ANALYSIS: Twenty studies were included. The main intervention approaches identified were nutrition education of individuals (i.e., education-based studies; EB) (n = 12), and manipulation of the food service environment (i.e., dining facility studies; DFACs) (n = 8). The most common strategies were face-to-face lectures (n = 8) for EB, and healthier menus (n = 7) and education of catering staff (n = 6) for DFAC interventions. Most studies (18/20) demonstrated favorable within-group effects; however, dietary changes were inconsistent. Five of 10 studies using a comparator group demonstrated positive between-group differences. CONCLUSION: Although potential exists for improving diet quality and nutrition knowledge in military populations, the heterogeneity of the studies to date limits conclusions on the most efficacious strategies.
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Servicios de Alimentación , Personal Militar , Dieta , Educación en Salud , Humanos , Estado NutricionalRESUMEN
AIMS: To evaluate the nutrition knowledge of elite Australian athletes, and to obtain feedback from sports dietitians on the Platform to Evaluate Athlete Knowledge of Sports Nutrition Questionnaires' (PEAKS-NQ) suitability. METHODS: Sports dietitians from the National Institute Network across Australia recruited athletes to complete the online, 50-item PEAKS-NQ which contained two sections (General Nutrition and Sports Nutrition). Sports dietitians provided feedback on the PEAKS-NQ using a 14-item questionnaire (with two open-ended items). The main outcome measures were nutrition knowledge score and tool suitability (usefulness, acceptability and feasibility) scores. For knowledge scores, independent t-tests, ANOVA and Chi-square tests were used to evaluate differences between groups. Suitability was evaluated using descriptive statistics. RESULTS: Twelve sports dietitians from the National Institute Network in Australia recruited a convenience sample of 240 athletes (21.3 ± 4.3 years, 63.5% female, 63.3% competed internationally). Athletes scored 70.7 ± 10.5%, with better general vs sports nutrition knowledge. Females had higher overall scores (P < .001) with no differences for age or sport played. University-educated athletes scored higher than non-tertiary educated athletes (P = .004). Knowledge gaps were identified in fats (role and food sources), recovery nutrition and managing body composition. Sports dietitians rated suitability of PEAKS-NQ positively with complete agreement on 8 of 12 items. CONCLUSIONS: Athletes have greater understanding of general nutrition compared to sports nutrition concepts and may benefit from education on applying nutrition in sports-specific contexts. Sports dietitians' responses showed PEAKS-NQ was a highly acceptable, feasible and useful measure.
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Conocimientos, Actitudes y Práctica en Salud , Ciencias de la Nutrición y del Deporte , Atletas , Australia , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
Diet quality indices are a practical, cost-effective method to evaluate dietary patterns, yet few have investigated diet quality in athletes. This study describes the relative validity and reliability of the recently developed Athlete Diet Index (ADI). Participants completed the electronic ADI on two occasions, 2 weeks apart, followed by a 4-d estimated food record (4-dFR). Relative validity was evaluated by directly comparing mean scores of the two administrations (mAdm) against scores derived from 4-dFR using Spearman's rank correlation coefficient and Bland-Altman (B-A) plots. Construct validity was investigated by comparing mAdm scores and 4-dFR-derived nutrient intakes using Spearman's coefficient and independent t test. Test-retest reliability was assessed using paired t test, intraclass correlation coefficients (ICC) and B-A plots. Sixty-eight elite athletes (18·8 (sd 4·2) years) from an Australian sporting institute completed the ADI on both occasions. Mean score was 84·1 (sd 15·2; range 42·5-114·0). The ADI had good reliability (ICC = 0·80, 95 % CI 0·69, 0·87; P < 0·001), and B-A plots (mean 1·9; level of agreement -17·8, 21·7) showed no indication of systematic bias (y = 4·57-0·03 × x) (95 % CI -0·2, 0·1; P = 0·70). Relative validity was evaluated in fifty athletes who completed all study phases. Comparison of mAdm scores with 4-dFR-derived scores was moderate (rs 0·69; P < 0·001) with no systematic bias between methods of measurement (y = 6·90-0·04 × x) (95 % CI -0·3, 0·2; P = 0·73). Higher scores were associated with higher absolute nutrient intake consistent with a healthy dietary pattern. The ADI is a reliable tool with moderate validity, demonstrating its potential for application to investigate the diet quality of athletes.
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Atletas , Registros de Dieta , Dieta , Adolescente , Australia , Humanos , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are essential for healthy development and protect against metabolic disease. However, individuals with obesity may be pre-disposed to experiencing lower n-3 PUFA status than normal-weight individuals. This cross-sectional study examined the relationship between the omega-3 index (O3I), body mass index (BMI) and dietary intake in healthy young women (n = 300; age = 18-35 y), a group not previously focused on. Intake was adjusted for energy using the residuals method, and associations were explored using independent t-tests and Pearson's correlations. Participants with obesity were found to have significantly lower O3I than normal-weight participants (p < 0.0001); however, no significant differences were observed in mean n-3 PUFA intakes. Even so, energy-adjusted intakes of n-3 PUFAs, with the exception of alpha-linolenic acid, were significantly correlated with O3I. This study demonstrates that O3I is influenced by both BMI and diet in young women; however the relationship between these two variables may be complex. Current intakes of n-3 PUFA observed in young women may not be effective in achieving target O3I levels in those with obesity, and further research is needed to find effective ways of improving n-3 PUFA status in a group already at increased risk of metabolic disease.
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Ácidos Grasos Omega-3/sangre , Obesidad/metabolismo , Adolescente , Adulto , Índice de Masa Corporal , Estudios Transversales , Dieta , Femenino , Humanos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Background: Sports nutrition knowledge (SNK) is essential for athletes to support selection of a diet to optimize sports performance. Unfortunately, assessment of SNK is limited by a lack of well-validated instruments. Valid assessment of SNK would assist in identifying gaps in athlete knowledge, as well as tailoring and evaluating nutrition education interventions.Objectives: The aim of this study was to develop and conduct content validation on a SNK questionnaire for athletes.Methods: Focus groups (FG) with experienced sports nutritionists at four elite sporting institutions in Australia and New Zealand were conducted to inform instrument development. FGs were recorded, transcribed verbatim and broad themes identified. Draft items for the Platform to Evaluate Athlete Knowledge of Sports Nutrition Questionnaire (PEAKS-NQ) were developed using FG themes, the scientific literature, and a sports nutrition position stand. FG participants were subsequently invited to review the PEAKS-NQ using a modified Delphi process to refine draft items and inform content validity.Results: Participants (n = 16; median experience 11.5 years) identified key assessment domains including general nutrition knowledge along with SNK and supported development of an electronic instrument with food images. The electronic PEAKS-NQ was subsequently developed and reviewed by a subset of FG participants (n = 11/16). This informed changes to 41/94 items with none removed. The final PEAKS-NQ assessed knowledge of food groups, macro- and micronutrients, competition nutrition, dietary supplements and skills in adjusting dietary intake to different situations.Conclusion: Minor adaptation to incorporate local foods would facilitate international use of the PEAKS-NQ. Further validation, including athlete performance on the instrument, is warranted.
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Rendimiento Atlético , Conocimientos, Actitudes y Práctica en Salud , Atletas , Electrónica , Humanos , Fenómenos Fisiológicos en la Nutrición Deportiva , Encuestas y CuestionariosRESUMEN
While athletes' nutrient intakes have been widely reported, few studies have assessed the diet quality of athletes. This is the first study to evaluate the diet quality of athletes using the purpose-built Athlete Diet Index (ADI). A convenience sample of 165 elite athletes from Australian sporting institutions completed the ADI online, with subsequent automated results provided to their respective accredited sports dietitians (ASDs). At the completion of athlete participation, ASDs (n = 12) responded to a range of survey items using a Likert scale (i.e., 1 = strongly agree to 5 = strongly disagree) to determine the suitability of the ADI in practice. Differences in ADI scores for demographics and sport-specific variables were investigated using independent t-tests, analysis of variance (ANOVA) and Bonferroni multiple comparisons. Spearman's rank correlation was used to assess the association between total scores and demographics. The mean total ADI score was 91.4 ± 12.2 (range 53-117, out of a possible 125). While there was no difference in total scores based on demographics or sport-specific variables; team sport athletes scored higher than individual sport athletes (92.7 vs. 88.5, P < 0.05). Athletes training fewer hours (i.e., 0-11 h/week) scored higher on Dietary Habits sub-scores compared with athletes training more hours (> 12 h/week; P < 0.05), suggesting that athletes who train longer may be at risk of a compromised dietary pattern or less than optimal nutrition practices that support training. Most (75%) ASDs surveyed strongly agreed with the perceived utility of the ADI for screening athletes and identifying areas for nutrition support, confirming its suitability for use in practice.
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Atletas/estadística & datos numéricos , Encuestas sobre Dietas/métodos , Conducta Alimentaria , Ciencias de la Nutrición y del Deporte/métodos , Adolescente , Adulto , Australia , Estudios Transversales , Encuestas sobre Dietas/estadística & datos numéricos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
PURPOSE: Early adulthood is a high-risk time for weight gain; however, young women with obesity are difficult to recruit to weight management programs. To encourage participation and retention, it is important to understand what young women want from these programs. The purpose of the study was to explore participants' perspectives on the features of an ideal weight management program. METHODS: Semi-structured interview schedules were used to elicit information from eight focus groups [27 women; mean age of 29.1 (± 5.1) years, mean body mass index (BMI; kg/m2) of 35.8 (± 2.9)]. The focus groups were transcribed, coded and analyzed qualitatively. RESULTS: The themes that emerged were program content, format, program characteristics, program name, location and duration. A major finding from the study is that participants value a program that includes nutritional, psychological and lifestyle interventions, and includes components that are not traditionally part of weight management programs such as body acceptance, sexual health and dressing and grooming. A program name that conveys wellness and body positivity was valued. Participants highlighted the importance of individualized programs that are also tailored to the needs of young adults, and delivered by credible and approachable staff who provide accountability. Cost-effectiveness, flexibility, accessibility, time-commitment were important considerations and the use of a combination of virtual and in-person methods (including group interventions) appealed to this cohort. CONCLUSION: Knowledge of program features which resonate with young women facilitates development of innovative ways to engage and support evidence-based weight management in this vulnerable group. LEVEL OF EVIDENCE: V.
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Programas de Reducción de Peso , Adulto , Índice de Masa Corporal , Femenino , Humanos , Estilo de Vida , Obesidad/terapia , Aumento de Peso , Adulto JovenRESUMEN
BACKGROUND: There is limited information on the dietary intakes of people with intellectual disability (ID) living in group homes. OBJECTIVE: To describe and evaluate dietary intake in people with ID. METHOD: Dietary intake was assessed in a convenience sample of people with ID living in group homes. Dietary assessment used three-day weighed food records and digital food photography. Intakes were compared to the Nutrient Reference Values (NRVs) and dietary recommendations. RESULTS: A sample of 33 adults, (men (M): n = 14; women (W): n = 19), mean age 51 ± 14 years, was recruited from seven group homes. Mean daily energy intake was low (M: 7.4 MJ; W: 7.0 MJ; p = 0.46), similar to levels recommended for bed rest. Many participants had intakes below the estimated average requirements (EARs) for the nutrients, magnesium (M: 86%; W: 63%), calcium (M: 43%; W: 78%), iodine (M: 43%; W: 47%) and zinc (M: 43%). Less than half of the recommended daily servings were consumed for vegetables (men and women) and dairy foods (women). CONCLUSION: Nutrient intake and diet quality of the participants in the group homes studied was poor. Education and policy to support healthier diets is required to improve dietary intake of people with intellectual disability, living in group homes.
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Ingestión de Energía , Hogares para Grupos , Discapacidad Intelectual , Política Nutricional , Adulto , Anciano , Dieta Saludable , Femenino , Humanos , Masculino , Persona de Mediana Edad , Necesidades Nutricionales , Estado Nutricional , Adulto JovenRESUMEN
BACKGROUND: Research indicates that low omega-3 polyunsaturated fatty acid (n-3 PUFA) may be associated with decreased cognitive function. This study examined the association between n-3 PUFA status and cognitive function in young Australian women. METHODS: This was a secondary outcome analysis of a cross-sectional study that recruited 300 healthy women (18-35 y) of normal weight (NW: BMI 18.5-24.9 kg/m2) or obese weight (OB: BMI ≥30.0 kg/m2). Participants completed a computer-based cognition testing battery (IntegNeuro™) evaluating the domains of impulsivity, attention, information processing, memory and executive function. The Omega-3 Index (O3I) was used to determine n-3 PUFA status (percentage of EPA (20:5n-3) plus DHA (22:6n3) in the red cell membrane) and the participants were divided into O3I tertile groups: T1 < 5.47%, T2 = 5.47-6.75%, T3 > 6.75%. Potential confounding factors of BMI, inflammatory status (C-reactive Protein), physical activity (total MET-min/wk), alpha1-acid glycoprotein, serum ferritin and hemoglobin, were assessed. Data reported as z-scores (mean ± SD), analyses via ANOVA and ANCOVA. RESULTS: Two hundred ninety-nine women (26.9 ± 5.4 y) completed the study (O3I data, n = 288). The ANOVA showed no overall group differences but a significant group × cognition domain interaction (p < 0.01). Post hoc tests showed that participants in the low O3I tertile group scored significantly lower on attention than the middle group (p = 0.01; ES = 0.45 [0.15-0.74]), while the difference with the high group was borderline significant (p = 0.052; ES = 0.38 [0.09-0.68]). After confounder adjustments, the low group had lower attention scores than both the middle (p = 0.01) and high (p = 0.048) groups. These findings were supported by univariate analyses which found significant group differences for the attention domain only (p = 0.004). CONCLUSIONS: Cognitive function in the attention domain was lower in women with lower O3I, but still within normal range. This reduced but normal level of cognition potentially provides a lower baseline from which cognition would decline with age. Further investigation of individuals with low n-3 PUFA status is warranted.
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Cognición , Ácidos Grasos Omega-3/sangre , Adolescente , Adulto , Atención , Índice de Masa Corporal , Estudios Transversales , Femenino , Humanos , Pruebas de Estado Mental y Demencia , Obesidad/sangre , Adulto JovenRESUMEN
Food-based diet indices provide a practical, rapid, and inexpensive way of evaluating dietary intake. Rather than nutrients, diet indices assess the intake of whole foods and dietary patterns, and compare these with nutrition guidelines. An athlete-specific diet index would offer an efficient and practical way to assess the quality of athletes' diets, guide nutrition interventions, and focus sport nutrition support. This study describes the development and validation of an Athlete Diet Index (ADI). Item development was informed by a review of existing diet indices, relevant literature, and in-depth focus groups with 20 sports nutritionists (median of 11 years' professional experience) from four elite athlete sporting institutes. Focus group data were analyzed (NVivo 11 Pro; QSR International Pty. Ltd., 2017, Melbourne, Australia), and key themes were identified to guide the development of athlete-relevant items. A modified Delphi survey in a subgroup of sports nutritionists (n = 9) supported item content validation. Pilot testing with athletes (n = 15) subsequently informed face validity. The final ADI (n = 68 items) was categorized into three sections. Section A (n = 45 items) evaluated usual intake, special diets or intolerances, dietary habits, and culinary skills. Section B (n = 15 items) assessed training load, nutrition supporting training, and sports supplement use. Section C (n = 8 items) captured the demographic details, sporting type, and caliber. All of the athletes reported the ADI as easy (40%) or very easy (60% of participants) to use and rated the tool as relevant (37%) or very relevant (63% of participants) to athletes. Further evaluation of the ADI, including the development of a scoring matrix and validation compared with established dietary methodology, is warranted.
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Atletas , Dieta , Conducta Alimentaria , Evaluación Nutricional , Estado Nutricional , Encuestas y Cuestionarios/normas , Femenino , Humanos , Masculino , Fenómenos Fisiológicos en la Nutrición DeportivaRESUMEN
Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD), which is itself an independent predictor of cardiovascular disease. Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce raised liver fat, yet there have been few randomized controlled trials with accurate measurement of liver fat. We assessed the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil versus placebo on quantified liver fat, liver tests, and body composition including visceral adipose tissue (VAT) in a double-blind randomized controlled trial. Fifty apparently healthy overweight men (BMI 25.0â»29.9 kg/m²; waist > 94 cm) were randomly allocated to consume fish oil (total daily dose: 1728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (olive oil capsules) daily for 12 weeks. Liver fat was assessed using proton magnetic resonance spectroscopy. All outcomes were assessed at baseline and following 6 and 12 weeks of supplementation. Baseline liver fat was 4.6 ± 0.5% (range: 0.6 to 18.2%); 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). Repeated measures ANOVA revealed no significant time or group × time effect for fish oil versus placebo for liver fat, liver enzymes, anthropometry, or body composition including VAT (p > 0.05 for all), with similar finding for sub-analysis of participants with NAFLD. Omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
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Aceites de Pescado/administración & dosificación , Grasa Intraabdominal/efectos de los fármacos , Hígado/efectos de los fármacos , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Sobrepeso , Adulto , Composición Corporal , Suplementos Dietéticos , Ácidos Grasos Omega-3/metabolismo , Humanos , Hígado/fisiología , MasculinoRESUMEN
AIM: Recruiting young women to weight management research programs is difficult. The purpose of this study was to gain insights into the barriers and motivators that influence participation and to explore effective methods of recruitment from the perspective of young women with obesity living in both urban and regional areas. METHODS: Semi-structured interviews were used to elicit information from focus groups. The interviews were transcribed, coded and analysed qualitatively. Eight focus groups, which included a total of 27 women, were conducted. Participants had a mean age of 29.1 (±5.1) years and a mean body mass index of 35.8 (±2.9) kg/m2 . RESULTS: The barriers to participation were multifaceted and largely similar across urban and regional participants. Fear of judgement and uncertainty about the process were major psychosocial barriers. A lack of tailoring of program content was an important program-related barrier. Physical barriers such as time commitment, cost and access were discussed extensively, particularly in urban groups. The provision of incentives and the use of positive language that focusses on the benefits of the intervention were viewed positively. Physical and virtual methods of recruitment were identified as potentially effective provided they were presented in media that this group is likely to use and can access in a private location. CONCLUSIONS: The results of this study provide a greater understanding of the challenges faced by young women in relation to participation in weight management programs and some of the potential methods that could be utilised to facilitate participation.
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Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Motivación , Obesidad/terapia , Selección de Paciente , Programas de Reducción de Peso/estadística & datos numéricos , Adolescente , Adulto , Australia , Femenino , Grupos Focales , Humanos , Entrevistas como Asunto , Juicio , Población Rural , Incertidumbre , Población Urbana , Adulto JovenRESUMEN
Sports nutrition recommendations provide guidance on dietary strategies to optimise sports performance. However, research indicates that young athletes often find it difficult to follow these guidelines in practice. Limited research exists on the determinants that influence adherence to sports nutrition guidelines. This study aimed to explore the perceptions and determinants of eating for health and performance in high-level male adolescent rugby union players. Determinants were explored using semi-structured individual interviews in New Zealand high-level male rugby union players (n = 20, 16â»18 years). Interviews were recorded, transcribed, and then underwent thematic analysis. Perceptions of eating for health and performance included balance and variety, appropriate portions, and specific foods. Both adolescent- and sport-specific determinants influenced the food choices of participants. Determinants relevant to adolescent lifestyles included the influence of significant others such as peers and family but also included the taste, cost, convenience, and availability of food. Sports-specific determinants revolved around the desire to enhance sports performance, motivation to perform, and team culture. The media (mainstream and social media), physical appearance, and feeling good were identified as both adolescent- and sport-specific factors influencing food choice. These findings highlight the importance of having support and positive role modelling to help young athletes make optimal food choices for health and performance. Strategies to further enable healthy eating practices should aim to strengthen the support available to young athletes in the home, school, and sporting environments and should include education on appropriate social media use to inform eating for health and performance.
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Nutrition literacy is linked to health via its influence on dietary intake. There is a need for a tool to assess nutrition literacy in research and dietetic practice. We sought guidance from nutrition professionals on topic areas and features of an electronic nutrition literacy assessment tool for Australian adults. 28 experienced nutrition professionals engaged in a range of nutrition and dietetic work areas participated in six focus groups using a semi-structured interview schedule. Data were analysed using an inductive approach using NVivo 10 (QSR International, Pty Ltd., Doncaster, Australia, 2012). Key areas identified to assess nutrition literacy included specific nutrients versus foods, labels and packaging, construction of the diet, knowledge of the Australian Dietary Guidelines and Australian Guide to Healthy Eating, understanding of serve and portion sizes, ability to select healthier foods, and demographics such as belief systems and culture. Exploitation of electronic features to enhance visual and auditory displays, including interactive animations such as "drag and drop" and virtual reality situations, were discussed. This study provided insight into the most relevant topic areas and presentation format to assess the nutrition literacy of adult Australians. The visual, auditory, and interactive capacity of the available technology could enhance the assessment of nutrition literacy.
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Recolección de Datos , Dietética/educación , Conocimientos, Actitudes y Práctica en Salud , Alfabetización en Salud , Estado Nutricional , Adulto , Australia , Conducta de Elección , Dieta Saludable , Estudios de Evaluación como Asunto , Grupos Focales , Embalaje de Alimentos , Preferencias Alimentarias , Humanos , Política Nutricional , Tamaño de la Porción , Factores Socioeconómicos , Encuestas y CuestionariosRESUMEN
Iron is an essential micronutrient for human health and inadequate intake may result in iron deficiency (ID) or iron deficiency anaemia (IDA). Unlike other recent studies investigating iron status in young women, this cross-sectional study analysed dietary intake and biochemical data from healthy young (18-35 years) women (n = 299) to determine the association between both haem iron (HI) and non-haem iron (NHI) intakes and serum ferritin (SF). Dietary restraint and possible inflammation secondary to obesity were also measured and accounted for, and energy intake was adjusted for using the residuals method. Independent samples t-tests and chi-squared tests were performed, and factors found to be significantly different between iron replete (IR) and ID/IDA participants were analysed using general linear modelling. ID/IDA participants consumed significantly lower total energy than iron replete (IR) (p = 0.003). Lower energy intake was also associated with higher levels of dietary restraint (p = 0.001). Both HI and NHI were positively associated with SF with HI was found to be a stronger predictor (ß = 0.128, p = 0.009) than NHI (ß = 0.037, p = 0.028). The study demonstrates that intake of both HI and NHI, as well as adequate dietary energy, are associated with normal iron status levels in young women, and that restrained eaters may be at greater risk of low iron status.
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Ferritinas/sangre , Hemo/administración & dosificación , Hierro de la Dieta/administración & dosificación , Hierro/sangre , Adolescente , Adulto , Antropometría , Australia/epidemiología , Proteína C-Reactiva/metabolismo , Restricción Calórica , Estudios Transversales , Dieta Reductora , Femenino , Hemoglobinas/metabolismo , Humanos , Hierro/administración & dosificación , Deficiencias de Hierro , Orosomucoide/metabolismo , Prevalencia , Factores Socioeconómicos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Women of reproductive age are at increased risk for iron deficiency (ID) and iron deficiency anemia (IDA), with both implicated in decreased cognitive function (CF). Obesity may complicate this association via inflammatory-mediated ferritin elevation. This cross-sectional study examined the association between hematological iron status (iron replete (IR), ID or IDA) and CF in healthy, young (18-35 years) women of normal-weight (NW: BMI 18.5-24.9 kg/m²) or obese-weight (OB: BMI >30 kg/m²). Participants completed a validated, computer-based cognition assessment evaluating impulsivity, attention, information processing, memory and executive function; CF reported as z-scores (mean ± SD). Iron status and CF were compared between groups via ANOVA, with adjustment for potential confounders (BMI, physical activity, C-reactive protein) via ANCOVA. A total of 157 NW and 142 OB women (25.8 ± 5.1 years) participated. Prevalence of ID and IDA were 14% and 6% respectively, with no significant difference between NW and OB groups. Women with IDA scored significantly lower on attention (although within normal range; ±1 z-score), compared to ID (IDA: -0.75 ± 1.89; ID: 0.53 ± 1.37; p = 0.004) but not IR (0.03 ± 1.33, p = 0.21) groups; there were no significant differences between ID and IR groups (p = 0.34). Adjustment for confounders did not significantly alter these results. In conclusion, women with IDA showed significantly reduced attention compared to women with ID.
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Anemia Ferropénica/complicaciones , Atención/fisiología , Deficiencias de Hierro , Adulto , Estudios Transversales , Femenino , Humanos , Obesidad , Salud de la Mujer , Adulto JovenRESUMEN
AIM: Regular aerobic exercise reduces visceral adipose tissue (VAT) and liver fat, however, not all individuals are able to adopt and adhere to such programs. Progressive resistance training (PRT) may be an alternative therapy, but there is limited available evidence. We examined the efficacy of PRT as per current exercise guidelines, compared with sham exercise placebo on liver fat and VAT. METHODS: Twenty-nine inactive and overweight/obese (body mass index ≥25 kg/m2 ) adults (age 29-59) were randomized to receive 8 weeks of PRT (n = 15, 10 exercises per session, 8-12 repetitions, 2-3 sets per exercise at 80-85% of one-repetition maximum, 3 days per week) or a sham exercise placebo control (CON) (n = 14). Change in liver fat, VAT, and abdominal s.c. adipose tissue (SAT) were assessed by magnetic resonance spectroscopy and imaging). RESULTS: There were no significant group by time interactions for change in liver fat in PRT versus CON groups (-0.07 ± 0.31% vs. 0.55 ± 0.77%, respectively, P = 0.19), VAT (-175 ± 85 cm3 vs. 10 ± 64 cm3 , respectively, P = 0.11), or abdominal SAT (-436 ± 245 cm3 vs. 127.29 ± 182 cm3 , respectively, P = 0.10) despite a significant increase in muscle volume (55 ± 78 cm3 vs. -0.04 ± 8 cm3 , respectively, P = 0.03). CONCLUSION: Traditional PRT is not effective for reducing liver fat in overweight/obese adults compared with placebo control. Although PRT has known metabolic benefits, an adequate volume of aerobic exercise should be promoted if liver fat is the therapeutic target.
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BACKGROUND: Low glycemic index (GI) pre-exercise meals may enhance endurance performance by maintaining euglycemia and altering fuel utilization. However, evidence for performance benefits is equivocal. OBJECTIVE: To evaluate the effect of a low GI (LGI) versus a high GI (HGI) pre-exercise meal on endurance performance using meta-analyses. METHODS: Data sources included MEDLINE, SPORTDiscus, AUSPORT, AusportMed, Web of Science, and Scopus. Eligibility criteria were randomized, crossover trials with an endurance exercise (≥60 min) component, e.g., time trial (TT), time to exhaustion (TTE) test, or submaximal bout followed by TT or TTE. Participants were healthy, active individuals aged ≥16 years. Interventions included a LGI (≤55) and HGI (≥70) meal ingested 30-240 min before exercise. Study quality was assessed using an adapted version of the validated Downs and Black tool. Effect size (ES) and 95 % confidence interval were calculated for each study and pooled according to performance test type and whether exogenous carbohydrate (CHO) was given during exercise. Potential effect modifiers including exercise duration, pre-exercise meal timing, glycemic load (GL), and fitness were assessed using meta-regression. RESULTS: The search netted 3431 citations with 19 studies eligible for inclusion (totaling 188 participants; 91 % male; VO2max: >50 ml/kg/min). Meals with 0.18-2 g CHO/kg body mass, and a mean GI and glycemic load of 82 (GL: 72) and 35 (GL: 32) for HGI and LGI, respectively, were given between 30 and 210 min before exercise. All test types without CHO ingestion during exercise showed slightly improved performance with LGI, but no significant pooled effects were observed (ES: -0.17 to -0.36; p > 0.05). Studies where exogenous CHO was ingested during exercise showed conflicting results (ES: -0.67 to 0.11; p = 0.04 to 0.94). No significant relationship was observed with any of the effect modifiers (p > 0.05). No consistent metabolic responses (glucose, insulin, lactate, respiratory exchange ratio) during exercise were observed with either meal type. LIMITATIONS: There were small numbers of studies within each exercise testing protocol and limited statistical power within studies. Pre-exercise meal timing, GL, meal composition and participant fitness varied across studies, limiting the capacity to assess the influence of these factors on study outcomes. CONCLUSION: There was no clear benefit of consuming a LGI pre-exercise meal for endurance performance regardless of carbohydrate ingestion during exercise.
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Carbohidratos de la Dieta , Ejercicio Físico , Índice Glucémico , Resistencia Física/fisiología , Glucemia/metabolismo , Prueba de Esfuerzo , Humanos , Insulina , Masculino , ComidasRESUMEN
Limited research addresses links between obesity and cognitive function in young adults. Objective. To investigate the relationship between obesity and cognitive function in young women. Methods. This cross-sectional study recruited healthy, young (18-35 y) women of normal (NW: BMI = 18.5-24.9 kg·m-2) or obese (OB: BMI ≥ 30.0 kg·m-2) weight. Participants completed a validated, computer-based cognitive testing battery evaluating impulsivity, attention, information processing, memory, and executive function. Questionnaires on depression and physical activity and a fasting blood sample for C-reactive protein and the Omega-3 Index were also collected. Cognition data are presented as z-scores (mean ± SD), and group comparisons were assessed via ANOVA. Potential confounding from questionnaire and blood variables were evaluated using ANCOVA. Results. 299 women (NW: n = 157; OB: n = 142) aged 25.8 ± 5.1 y were enrolled. Cognition scores were within normal range (±1 z-score), but OB had lower attention (NW: 0.31 ± 1.38; OB: -0.25 ± 1.39; ES: 0.41, CI: 0.17-0.64; p < 0.001) and higher impulsivity (NW: 0.36 ± 1.14; OB: -0.07 ± 1.07; ES: 0.39, CI: 0.15-0.62; p=0.033). Confounder adjustment had minimal impact on results. Conclusion. The OB group had normal but significantly lower performance on attention and were more impulsive compared to NW participants. This may indicate early cognitive decline, but longitudinal research confirming these findings is warranted.