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1.
Pilot Feasibility Stud ; 7(1): 172, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34493322

RESUMO

BACKGROUND: Prolonged sitting increases the risk of cardio-metabolic disease. Office-based employees are particularly susceptible to high rates of this sedentary behaviour during work hours. Laboratory studies indicate that regularly interrupting periods of prolonged sitting with short bouts (2 min) of physical activity can improve markers of cardio-metabolic health. This method of interrupting sitting time is yet to be tested in an occupational setting and may provide an alternative to providing sit-to-stand desks. Drawing on the Behaviour Change Wheel and evidence on the barriers and motivators to performing regular activity breaks, the Move More @ Work intervention was developed. The objectives of this pilot study are to examine the feasibility, and preliminary outcomes, of this intervention designed to encourage participants to perform 1-2 min of activity after every 30 min of continuous sitting throughout the work day. The study will inform if progress to a full effectiveness trial is warranted. METHODS: An interrupted time series design consisting of a 4-week baseline (control period), a 12-week intervention, and a 12-week follow-up will be utilised. At least 57 university employees who self-report spending > 5 h per day sitting at work on at least 3 days per week will be recruited to participate. The intervention consists of (1) a structured consultation with a Move More @ Work coach, containing a number of behaviour change techniques to create an individualised plan of how to incorporate the activity breaks into the working day, and (2) strategies to create a supportive workplace culture for performing the activity breaks. Feasibility will be assessed by recruitment and retention rates, and acceptability of the intervention. Pilot outcomes are the number of regular activity breaks taken during the workday, cardio-metabolic risk score and self-reported health, and work-related productivity outcomes. DISCUSSION: If the Move More @ Work intervention is shown to be feasible, acceptable, and shows evidence of effectiveness, this will provide justification for the progression to a full scale evaluation of the intervention. In the longer-term, this intervention may provide an alternative means of improving health outcomes through interrupting sedentary time than that offered by current sedentary behaviour interventions. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12620000354987 . Registered on 12 March 2020.

2.
Public Health Nutr ; : 1-9, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34348827

RESUMO

OBJECTIVE: This study aimed to describe meat consumption rationalisation and relationships with meat consumption patterns and food choice motivations in New Zealand adolescents. DESIGN: This was a cross-sectional study of adolescents from high schools across New Zealand. Demographics, dietary habits, and motivations and attitudes towards food were assessed by online questionnaire and anthropometric measurements taken by researchers. The 4Ns questionnaire assessed meat consumption rationalisation with four subscales: 'Nice', 'Normal', 'Necessary' and 'Natural'. SETTING: Nineteen secondary schools from eight regions in New Zealand, with some purposive sampling of adolescent vegetarians in Otago, New Zealand. PARTICIPANTS: Questionnaires were completed by 385 non-vegetarian and vegetarian (self-identified) adolescents. RESULTS: A majority of non-vegetarian adolescents agreed that consuming meat was 'nice' (65 %), but fewer agreed that meat consumption was 'necessary' (51 %). Males agreed more strongly than females with all 4N subscales. High meat consumers were more likely to agree than to disagree that meat consumption was nice, normal, necessary and natural, and vegetarians tended to disagree with all rationalisations. Adolescent non-vegetarians whose food choice was motivated more by convenience, sensory appeal, price and familiarity tended to agree more with all 4N subscales, whereas adolescents motivated by animal welfare and environmental concerns were less likely to agree. CONCLUSIONS: To promote a reduction in meat consumption in adolescents, approaches will need to overcome beliefs that meat consumption is nice, normal, necessary and natural.

3.
Artigo em Inglês | MEDLINE | ID: mdl-34360325

RESUMO

BACKGROUND: Tools that assess all three components of 24 h movement guidelines (sleep, physical activity, and screen use) are scarce. Our objective was to use a newly developed Screen Time and Activity Recall (STAR-24) to demonstrate how this tool could be used to illustrate differences in time-use across the day between two independent samples of male adolescents collected before and during the COVID-19 lockdown. METHODS: Adolescent boys aged 15-18 years (n = 109) each completed the STAR-24 twice, n = 74 before lockdown and n = 35 during lockdown. RESULTS: During lockdown more than 50% of the sample reported gaming between 10 a.m. and 12 noon, transport was not reported as an activity, and activities of daily living spiked at mealtimes. Gaming and screen time were more prevalent in weekends than weekdays, with the highest prevalence of weekday screen use (before lockdown) occurring between 8 and 9 p.m. Differences in estimates of moderate-to-vigorous physical activity prior to and during lockdown (mean difference (95% CI); 21 (-9 to 51) min) and sleep (0.5 (-0.2 to 1.2) h) were small. Total and recreational screen time were higher during lockdown (2 h (0.7 to 3.3 h) and 48 min (-36 to 132 min), respectively). CONCLUSIONS: The STAR-24 holds promise as a single tool that assesses compliance with 24 h movement guidelines. This tool also allows clear illustration of how adolescent boys are using their time (instead of only providing summary measures), providing richer data to inform public health initiatives.


Assuntos
COVID-19 , Atividades Cotidianas , Adolescente , Controle de Doenças Transmissíveis , Humanos , Masculino , Nova Zelândia , SARS-CoV-2 , Comportamento Sedentário
4.
Artigo em Inglês | MEDLINE | ID: mdl-34360371

RESUMO

BACKGROUND: The majority of adolescents do less physical activity than is recommended by the World Health Organization. Active commuting and participation in organised sport and/or physical education individually have been shown to increase physical activity in adolescents. However, how these domains impact physical activity both individually and in combination has yet to be investigated in a sample of New Zealand female adolescents from around the country. METHODS: Adolescent females aged 15-18 y (n = 111) were recruited from 13 schools across eight locations throughout New Zealand to participate in this cross-sectional study. Participants completed questions about active commuting, and participation in organised sport and physical education, before wearing an Actigraph GT3X (Actigraph, Pensacola, FL, USA) +24 h a day for seven consecutive days to determine time spent in total, MVPA and light physical activity. RESULTS: Active commuters accumulated 17 min/d (95% CI 8 to 26 min/d) more MVPA compared to those who did not. Those who participated in sport accumulated 45 min/d (95% CI 20 to 71 min/d) more light physical activity and 14 min/d (95% CI 5 to 23 min/d) more MVPA compared to those who did not. Participation in physical education did not seem to have a large impact on any component of physical activity. Participation in multiple domains of activity, e.g., active commuting and organised sport, was associated with higher accumulation of MVPA but not light activity. Conclusion Active commuting and sport both contribute a meaningful amount of daily MVPA. Sport participation has the potential to increase overall activity and displace sedentary behaviour. A combination of physical activity domains may be an important consideration when targeting ways to increase physical activity in adolescent females.


Assuntos
Exercício Físico , Educação Física e Treinamento , Adolescente , Estudos Transversais , Feminino , Humanos , Nova Zelândia , Transportes
5.
Nutrients ; 13(6)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203997

RESUMO

Diet is one of the strongest modifiable risk factors for hypertension. In this study, we described the associations between dietary factors and blood pressure; and explored how weight status moderated these associations in a sample of New Zealand male adolescents. We collected demographics information, anthropometric, blood pressure, and dietary data from 108 male adolescents (15-17 years old). Mixed effects and logistic regression models were used to estimate relationships between dietary variables, blood pressure, and hypertension. Moderation effects of overweight status on the relationship between hypertension and diet were explored through forest plots. One-third (36%) of the sample was classified as hypertensive. Fruit intake was related to significantly lower systolic (-2.4 mmHg, p = 0.005) and diastolic blood pressure (-3.9 mmHg, p = 0.001). Vegetable and milk intake was related to significantly lower diastolic blood pressure (-1.4 mmHg, p = 0.047) and (-2.2 mmHg, p = 0.003), respectively. In overweight participants, greater vegetable and milk, and lower meat intake appeared to reduce the odds of hypertension. Certain dietary factors may have more prominent effects on blood pressure depending on weight status.


Assuntos
Pressão Sanguínea , Dieta , Hipertensão/etiologia , Sobrepeso/complicações , Adolescente , Animais , Índice de Massa Corporal , Estudos Transversais , Frutas , Humanos , Masculino , Leite , Nova Zelândia , Inquéritos Nutricionais , Obesidade/complicações , Fatores de Risco , Inquéritos e Questionários , Verduras
6.
J Hum Nutr Diet ; 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33999481

RESUMO

BACKGROUND: The measurement of height is crucial for weight status assessment. When standing height is difficult to measure, ulna length may offer a convenient and accurate surrogate of height measure. Adolescence is a period of accelerated linear growth; hence, the validation of age-specific equations that predict height from ulna length in adolescents is warranted. The present study aimed to develop and validate age- and sex-specific equations for predicting height from ulna length in New Zealand adolescents. METHODS: Height, weight and ulna length were measured in 364 adolescents (n = 110 males, n = 254 females) aged 15.0-18.8 years, who were enrolled in the SuNDiAL (Survey of Nutrition Dietary Assessment and Lifestyle) project, a cross-sectional survey performed in 2019 and 2020. Regression models were used to determine equations to predict height from ulna length. Agreement between measured and predicted height, body mass index (BMI) and BMI z-score was assessed with intra-class correlation coefficients (ICC) and Bland-Altman plots. Sensitivity and specificity were calculated for classifying obesity. RESULTS: Strong agreement was found between predicted and measured height (ICC = 0.78; mean difference = 0; 95% confidence interval = -0.5 to 0.5 cm) and BMI (ICC = 0.95; mean difference = 0; 95% confidence interval = -0.1 to 0.1 kg m-2 ). Predicted height was 88.1% accurate when classifiying weight status, showing high sensitivity (93.8%) and specificity (99.4%) for classifying obesity. CONCLUSIONS: Ulna length measurement can accurately estimate height and subsequently weight status in New Zealand adolescents aged 15-18 years.

7.
PLoS One ; 16(1): e0244841, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33395691

RESUMO

The objective of this study was to compare acute effects of prolonged sitting, prolonged standing and sitting interrupted with regular activity breaks on vascular function and postprandial glucose metabolism. In a randomized cross-over trial, 18 adults completed: 1. Prolonged Sitting; 2. Prolonged Standing and 3. Sitting with 2-min walking (5 km/h, 10% incline) every 30 min (Regular Activity Breaks). Flow mediated dilation (FMD) was measured in the popliteal artery at baseline and 6 h. Popliteal artery hemodynamics, and postprandial plasma glucose and insulin were measured over 6 h. Neither raw nor allometrically-scaled FMD showed an intervention effect (p = 0.285 and 0.159 respectively). Compared to Prolonged Sitting, Regular Activity Breaks increased blood flow (overall effect of intervention p<0.001; difference = 80%; 95% CI 34 to 125%; p = 0.001) and net shear rate (overall effect of intervention p<0.001; difference = 72%; 95% CI 30 to 114%; p = 0.001) at 60 min. These differences were then maintained for the entire 6 h. Prolonged Standing increased blood flow at 60 min only (overall effect of intervention p<0.001; difference = 62%; 95% CI 28 to 97%; p = 0.001). Regular Activity Breaks decreased insulin incremental area under the curve (iAUC) when compared to both Prolonged Sitting (overall effect of intervention P = 0.001; difference = 28%; 95% CI 14 to 38%; p<0.01) and Prolonged Standing (difference = 19%; 95% CI 4 to 32%, p = 0.015). There was no intervention effect on glucose iAUC or total AUC (p = 0.254 and 0.450, respectively). In normal-weight participants, Regular Activity Breaks induce increases in blood flow, shear stress and improvements in postprandial metabolism that are associated with beneficial adaptations. Physical activity and sedentary behaviour messages should perhaps focus more on the importance of frequent movement rather than simply replacing sitting with standing.


Assuntos
Pressão Arterial/fisiologia , Exercício Físico/fisiologia , Hiperglicemia/metabolismo , Adulto , Área Sob a Curva , Glicemia/metabolismo , Estudos Cross-Over , Feminino , Glucose/metabolismo , Hemodinâmica/fisiologia , Humanos , Insulina/metabolismo , Insulina Regular Humana/metabolismo , Masculino , Período Pós-Prandial , Comportamento Sedentário , Postura Sentada , Posição Ortostática , Triglicerídeos/sangue , Caminhada/fisiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-32878296

RESUMO

Despite activity guidelines moving towards a 24-h focus, we have a poor understanding of the 24-h activity patterns of adolescents. Therefore, this study aims to describe the 24-h activity patterns of a sample of adolescent females and investigate the association with body mass index (BMI). Adolescent females aged 15-18 years (n = 119) were recruited across 13 schools in 8 locations throughout New Zealand. Actigraph GT3X+ accelerometers were worn 24-h a day for seven days and the output was used to identify time spent in each 24-h component (sleep, sedentary, light-intensity physical activity and moderate-to-vigorous intensity physical activity). In a 24-h period, adolescent females spent approximately half their time sedentary, one third sleeping and the remainder in light-intensity physical activity (15%) and moderate-to-vigorous intensity physical activity (5%). Higher BMI z-scores were associated with 16 min more time spent in light-intensity physical activity. Additionally, those with higher BMI were less likely to meet the sleep and physical activity guidelines for this age group. Compliance with the moderate-to-vigorous intensity physical activity guidelines, sleep guidelines, or both, was low, especially in those classified as overweight or obese. The association between BMI and light activity warrants further investigation.


Assuntos
Índice de Massa Corporal , Exercício Físico , Comportamento Sedentário , Sono , Acelerometria , Adolescente , Estudos Transversais , Feminino , Humanos , Nova Zelândia/epidemiologia
9.
J Sports Sci ; 38(22): 2517-2524, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32648521

RESUMO

Interrupting sedentary behaviour with regular activity breaks benefits glycaemic control; however, the influence of the energy utilised during these activity breaks on postprandial metabolic response is relatively unknown. Therefore, the aim of this study was to investigate whether the energy utilisation of regular (every 30 min) short (1 min 40 s or 2 min) activity breaks was associated with the lowering of postprandial glycaemia, insulinemia and lipidemia.Using separate data from two previously performed studies (ALPhA Study n = 65, age 25.7 (5.2) y, 40% male, BMI 23.6 (4.1) kg · m-2. ABPA study n = 35, age 25.1 (3.7) y, 31% male, BMI 23.4 (3.2) kg · m-2) we investigated the association between energy utilisation (measured by indirect calorimetry) and postprandial glucose, insulin and triglycerides during prolonged sitting, and regular activity breaks.Results.Mixed effects regression models indicated that energy utilisation was not consistently associated with postprandial glucose, insulin or triglyceride responses (p > 0.05 for all). Additionally, there was some indication that energy utilisation was obscuring (mildly suppressing) the effects of regular activity breaks on glucose, insulin and triglyceride iAUC.Conclusions.If energy utilisation does not mediate the association between regular activity breaks and postprandial glycaemic response, it is possible that it is the frequency of the activity breaks that is beneficial.


Assuntos
Metabolismo Energético , Exercício Físico/fisiologia , Período Pós-Prandial/fisiologia , Comportamento Sedentário , Postura Sentada , Adolescente , Adulto , Área Sob a Curva , Glicemia/metabolismo , Calorimetria Indireta , Metabolismo dos Carboidratos , Feminino , Humanos , Insulina/sangue , Metabolismo dos Lipídeos , Masculino , Oxirredução , Triglicerídeos/sangue , Adulto Jovem
10.
JMIR Res Protoc ; 9(5): e17310, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32459178

RESUMO

BACKGROUND: Anecdotally, vegetarian eating patterns seem to be increasing in parallel with growing concerns about environmental sustainability. While this pattern of eating is widely believed to be associated with benefits for the planet and individual health, it may increase the risk of inadequate intakes and nutrient deficiency if not planned carefully. Adolescent girls may be particularly at risk, as they have increased requirements for nutrients such as iron, zinc, calcium, and vitamin B12 during growth and development. OBJECTIVE: The objective of the SuNDiAL Project (Survey of Nutrition, Dietary Assessment, and Lifestyles) is to compare the dietary intakes and habits, nutrition status, motivations, attitudes, and physical activity of a sample of vegetarian and nonvegetarian adolescent girls in New Zealand. METHODS: A clustered, cross-sectional, nationwide study of adolescents aged 15-18 years was conducted. Secondary schools were recruited throughout New Zealand, and pupils (n=290) were invited to participate in data collection in either the first (February to April) or third (August to October) school term of 2019 (New Zealand schools operate on a 4-term year). Sociodemographic and health information; vegetarian status; dietary habits; and attitudes, motivations, and beliefs regarding food choices were assessed via an online self-administered questionnaire. Dietary intakes were collected via two 24-hour diet recalls on nonconsecutive days and will be adjusted for within-person variation using the Multiple Source Method, to represent usual intakes. Nutrient adequacy will be assessed by the estimated average requirement cut-point method or probability approach as appropriate. Height and weight were measured, and blood and urine samples collected for micronutrient status assessment. Participants wore an accelerometer for 7 days to assess 24-hour activity patterns (time spent asleep, sedentary, or engagement in light-intensity or moderate-to-vigorous intensity physical activity). RESULTS: Recruitment and data collection were conducted in 2019. Data are currently being cleaned and analyzed, with publication of the main results anticipated at the end of 2020. CONCLUSIONS: The SuNDiAL Project will provide a meaningful and timely description of diet, nutrition status, and motivational factors associated with vegetarianism and identify any risks this pattern of eating may pose for female adolescents. The results of this study will support the development of targeted recommendations and interventions aimed at enhancing the health, growth, and development of adolescent girls. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12619000290190; https://tinyurl.com/yaumh278. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/17310.

11.
J Occup Environ Med ; 62(4): 317-324, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32049875

RESUMO

OBJECTIVE: To understand the practicalities of undertaking 2 to 3 minutes of light to moderate intensity physical activity after every 30 minutes of prolonged sitting by examining barriers and facilitators. METHODS: Around 27 (n = 22 women) employees working in higher education who sat for greater than 5 hours during a work day participated in a focus group discussion. RESULTS: Through inductive thematic analysis, themes characterising workplace culture and having the knowledge (or not) of benefits were found to be a facilitator and a barrier. Additional barriers were a perceived reduction in work productivity and specific work tasks that precluded taking activity breaks. Extrinsic motivators and prompts were suggested to facilitate participation. CONCLUSIONS: Environmental and individual strategies are required to build capability, opportunity, and motivation for undertaking regular activity breaks and should inform the development of an ecologically valid workplace intervention.


Assuntos
Promoção da Saúde , Saúde do Trabalhador , Comportamento Sedentário , Local de Trabalho , Adulto , Eficiência , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Postura , Postura Sentada
12.
J Occup Environ Med ; 60(12): 1150-1157, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30308622

RESUMO

OBJECTIVE: The aim of this study was to describe device-measured patterns of sedentary behavior in self-identified sedentary university employees. METHODS: Participants (n = 78) wore the ActiGraph GT3X+ and the activPAL3 for 7 days. Data from the ActiGraph were used to identify time in sedentary behavior, light-intensity, and moderate-to-vigorous physical activity. Data from the activPAL identified time sitting/lying, standing, and stepping. Breaks in sedentary time and prolonged sedentary bouts were described. RESULTS: During workdays, participants spent 65% to 79% of time sedentary, 16% in light-intensity physical activity, and 4% in moderate-to-vigorous physical activity, 76% of time was spent sitting/lying, 16% standing, and 8% stepping. Between 10 and 12 breaks in sedentary time were accumulated. CONCLUSION: Office-based university employees spend a high proportion of their time sedentary, but accumulate a high number of breaks. Whether these breaks are appropriate in timing, duration, and intensity to elicit health benefits seen in laboratory studies requires further investigation.


Assuntos
Actigrafia , Pessoal Administrativo , Exercício Físico , Comportamento Sedentário , Universidades , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico , Fatores de Tempo , Local de Trabalho
13.
Sports Med ; 48(10): 2347-2366, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30078066

RESUMO

OBJECTIVE: The aim was to conduct a systematic review and meta-analysis analyzing the impact of up to 24 h of prolonged sitting on postprandial glucose, insulin and triglyceride responses, blood pressure and vascular function, in comparison to sitting interrupted with light- to moderate-intensity physical activity. METHODS: To be included, studies had to examine the impact of prolonged sitting lasting < 24 h in apparently healthy males or females of any age. Studies were identified from searches of the MEDLINE, CINAHL and SportDISCUS databases on July 6, 2016. Study quality was assessed using the Downs and Black Checklist; publication bias was assessed via funnel plot. RESULTS: Forty-four studies met the inclusion criteria for the systematic review; of these, 20 were included in the meta-analysis, which compared prolonged sitting to the effects of interrupting sitting with regular activity breaks on postprandial glucose, insulin and triglycerides. When compared to prolonged sitting, regular activity breaks lowered postprandial glucose (d = - 0.36, 95% confidence interval [CI] - 0.50 to - 0.21) and insulin (d = - 0.37, 95% CI - 0.53 to - 0.20), but not triglyceride responses (d = 0.06, 95% CI - 0.15 to 0.26). Subgroup analyses indicated reductions in postprandial triglyceride responses only occurred 12-16 h after the intervention. The magnitude of the reductions in glucose, insulin or triglyceride response was not modified by the intensity of the activity breaks, the macronutrient composition of the test meal, or the age or body mass index of participants. CONCLUSION: Prolonged sitting results in moderate elevations in postprandial glucose and insulin responses when compared to sitting interrupted with activity breaks. PROSPERO ID: CRD42015020907.


Assuntos
Glicemia/análise , Insulina/sangue , Comportamento Sedentário , Postura Sentada , Pressão Sanguínea , Humanos , Refeições , Período Pós-Prandial , Ensaios Clínicos Controlados Aleatórios como Assunto , Triglicerídeos/sangue , Rigidez Vascular
14.
Nutrients ; 10(2)2018 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-29373503

RESUMO

Regular activity breaks increase energy expenditure; however, this may promote compensatory eating behaviour. The present study compared the effects of regular activity breaks and prolonged sitting on appetite. In a randomised, cross-over trial, 36 healthy adults (BMI (Body Mass Index) 23.9 kg/m² (S.D. = 3.9)) completed four, two-day interventions: two with prolonged sitting (SIT), and two with sitting and 2 min of walking every 30 min (RAB). Standardized meals were provided throughout the intervention, with an ad libitum meal at the end of Day 2. Appetite and satiety were assessed throughout both days of each intervention using five visual analogue scales. The five responses were combined into a single appetite response at each time point. The area under the appetite response curve (AUC) was calculated for each day. Intervention effects for appetite response AUC and ad libitum meal intake were tested using linear mixed models. Appetite AUC did not differ between interventions (standardised effect of RAB compared to SIT: Day 1: 0.11; 95% CI: -0.28, 0.06; p = 0.212; Day 2: 0.04; 95% CI: -0.15, 0.24; p = 0.648). There was no significant difference in energy consumed at the ad libitum lunch meal on Day 2 between RAB and SIT. Interrupting prolonged sitting with regular activity breaks does not acutely influence appetite or volume of food consumed, despite inferred increases in energy expenditure. Longer-term investigation into the effects of regular activity breaks on energy balance is warranted.


Assuntos
Regulação do Apetite , Comportamento Sedentário , Saúde da População Urbana , Caminhada , Adolescente , Adulto , Estudos Cross-Over , Ingestão de Energia , Metabolismo Energético , Exercício Físico , Feminino , Humanos , Masculino , Refeições , Nova Zelândia , Resposta de Saciedade , Autorrelato , Fatores de Tempo , Adulto Jovem
15.
Sports Med ; 48(3): 585-595, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29189928

RESUMO

BACKGROUND: The cumulative effect of too much sedentary behavior may contribute to weight gain and obesity. OBJECTIVE: The aim of this study was to conduct a systematic review and meta-analysis of prospective cohorts and randomized controlled studies to determine the association between sedentary behavior and body weight and obesity in adults. DATA SOURCES AND STUDY SELECTION: Relevant studies were identified from searches of the MEDLINE, Embase, AMED and PubMed databases up to May 2017, and by manual searches of in-text citations. Studies that evaluated the association in adults between sedentary behavior and body weight or obesity, while controlling for physical activity, were included. Overall, 31 publications met the eligibility criteria, including 23 prospective cohort studies with data that could be extracted for a quantitative meta-analysis, and a single randomized controlled trial. RESULTS: There were no significant associations between sedentary behavior and any measure of body weight or obesity, with the exception of waist circumference. For the latter outcome, over a 5-year follow-up period, each 1 h per day increase-from baseline to follow-up-in sedentary behavior was associated with a 0.02 mm [95% confidence interval (CI) 0.01-0.04; p = 0.001) increase in waist circumference. The odds ratio of becoming overweight or obese was 1.33 (95% CI 1.11-1.60; p = 0.001) in the highest compared with lowest categories of sedentary behavior. CONCLUSIONS: Meta-analysis of data from prospective cohort studies showed small, inconsistent and non-significant associations between sedentary behavior and body weight.


Assuntos
Composição Corporal , Peso Corporal , Obesidade , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento Sedentário , Adolescente , Adulto , Humanos
17.
J Clin Lipidol ; 11(5): 1268-1279.e1, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28673802

RESUMO

BACKGROUND: Compared with prolonged sitting, regular activity breaks immediately lower postprandial glucose and insulin, but not triglyceride responses. Postprandial triglycerides can be lowered by physical activity but the effect is often delayed by ∼12 to 24 hours. OBJECTIVE: The objective of the study was to determine whether regular activity breaks affect postprandial triglyceride response in a delayed manner similar to physical activity. METHODS: In a randomized crossover trial, 36 adults (body mass index 23.9 kg/m2 [standard deviation 3.9]) completed four 2-day interventions: (1) prolonged sitting (SIT); (2) prolonged sitting with 30 minutes of continuous walking (60% VO2max), at the end of Day 1 (SIT + PAD1); (3) Sitting with 2 minutes of walking (60% VO2max) every 30 minutes (RAB); (4) A combination of the continuous walking and regular activity breaks in 2 and 3 above (RAB + PAD1). Postprandial plasma triglyceride, nonesterified fatty acids, glucose, and insulin responses were measured in venous blood over 5 hours on Day 2. RESULTS: Compared with SIT, both RAB (difference: -43.61 mg/dL·5 hours; 95% confidence interval [CI] -83.66 to -2.67; P = .035) and RAB + PAD1 (-65.86 mg/dL·5 hours; 95% CI -112.14 to -19.58; P = .005) attenuated triglyceride total area under the curve (tAUC). RAB + PAD1 produced the greatest reductions in insulin tAUC (-23%; 95% CI -12% to -31%; P < .001), whereas RAB resulted in the largest increase in nonesterified fatty acids (tAUC, 10.08 mg/dL·5 hours; 95% CI 5.60-14.84; P < .001). There was no effect on glucose tAUC (P = .290). CONCLUSIONS: Postprandial triglyceride response is attenuated by regular activity breaks, when measured ∼24 hours after breaks begin. Combining regular activity breaks with 30 minutes of continuous walking further improves insulinemic and lipidemic responses.


Assuntos
Exercício Físico , Ácidos Graxos não Esterificados/sangue , Voluntários Saudáveis , Período Pós-Prandial , Triglicerídeos/sangue , Adulto , Estudos Cross-Over , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
18.
J Phys Act Health ; 12(8): 1133-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25329006

RESUMO

BACKGROUND: Interrupting sedentary time induces improvements in glucose metabolism; however, it is unclear how much activity is required to reduce the negative effects of prolonged sitting. METHODS: Sixty-six participants sat continuously for 9 hours except for required bathroom breaks. Participants were fed meal replacement beverages at 60, 240 and 420 min. Blood samples were obtained hourly for 9 hours, with additional samples collected 30 and 45 min after each feeding. Responses were calculated as incremental area under the curve (iAUC) for plasma glucose, insulin and triglyceride. Participants wore a triaxial accelerometer and a heart rate monitor. Energy expenditure was estimated using indirect calorimetry. RESULTS: After controlling for age, sex and BMI, every 100 count increase in accelerometer derived total movement was associated with a 0.06 mmol·L-1·9 hours decrease in glucose iAUC (95% CI 0.004-0.1; P = .035), but not associated with changes in insulin or triglyceride iAUC. Every 1 bpm increase in mean heart rate was associated with a 0.76 mmol·L-1·9 hours increase in triglyceride iAUC (95% CI 0.13-1.38). CONCLUSION: Accelerometer measured movement during periods of prolonged sitting can result in minor improvements in postprandial glucose metabolism, but not lipid metabolism.


Assuntos
Acelerometria/métodos , Metabolismo Energético/fisiologia , Glucose/metabolismo , Metabolismo dos Lipídeos/fisiologia , Período Pós-Prandial/fisiologia , Comportamento Sedentário , Adulto , Área Sob a Curva , Glicemia/análise , Calorimetria Indireta , Feminino , Humanos , Insulina/sangue , Masculino , Postura/fisiologia , Triglicerídeos/sangue
19.
Public Health Nutr ; 17(7): 1447-53, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23835153

RESUMO

OBJECTIVE: Mandatory folic acid fortification of breads in New Zealand was put on hold in 2009. At this time, bread manufacturers were requested to adopt greater voluntary fortification and agreed to add folic acid to approximately one-third of their bread range. We sought to evaluate the impact of increased voluntary fortification of bread and the proposed mandatory fortification programme on folate intake adequacy of reproductive-age women. DESIGN: Cross-sectional study conducted in 2008. Dietary data were collected using 3 d weighed food records and usual folate intakes were generated by modifying the food composition table as follows: (i) voluntary fortification of bread as of 2008 (six breads); (ii) increased voluntary fortification of bread as of 2011 (thirty-four breads); and (iii) mandatory fortification of all breads. The prevalence of inadequate folate intake was calculated for all three scenarios using the Estimated Average Requirement (320 µg dietary folate equivalents/d) cut-point method. SETTING: New Zealand. SUBJECTS: Healthy non-pregnant women (n 125) aged 18-40 years. RESULTS: Usual folate intake in 2008 was 362 µg dietary folate equivalents/d. Increased voluntary bread fortification led to a marginal increase in folate intakes (394 µg dietary folate equivalents/d) and a decline in inadequacy from 37 % to 29 %. Mandatory fortification resulted in an increase of 89 µg folic acid/d, which substantially shifted both the proportion of women with folic acid intakes above 100 µg/d and the distribution of overall folate intakes, producing a marked reduction in inadequacy to 5 %. CONCLUSIONS: Increased voluntary bread fortification efforts are far inferior to mandatory fortification as a reliable public health intervention.


Assuntos
Dieta , Deficiência de Ácido Fólico/prevenção & controle , Ácido Fólico/administração & dosagem , Indústria Alimentícia/legislação & jurisprudência , Alimentos Fortificados , Defeitos do Tubo Neural/prevenção & controle , Política Nutricional/legislação & jurisprudência , Adolescente , Adulto , Pão , Estudos Transversais , Feminino , Ácido Fólico/uso terapêutico , Deficiência de Ácido Fólico/etiologia , Regulamentação Governamental , Humanos , Nova Zelândia , Avaliação Nutricional , Necessidades Nutricionais , Saúde da Mulher , Adulto Jovem
20.
Am J Clin Nutr ; 98(2): 358-66, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23803893

RESUMO

BACKGROUND: Sedentary behavior is a risk factor for cardiometabolic disease. Regularly interrupting sedentary behavior with activity breaks may lower this risk. OBJECTIVE: We compared the effects of prolonged sitting, continuous physical activity combined with prolonged sitting, and regular activity breaks on postprandial metabolism. DESIGN: Seventy adults participated in a randomized crossover study. The prolonged sitting intervention involved sitting for 9 h, the physical activity intervention involved walking for 30 min and then sitting, and the regular-activity-break intervention involved walking for 1 min 40 s every 30 min. Participants consumed a meal-replacement beverage at 60, 240, and 420 min. RESULTS: The plasma incremental area under the curve (iAUC) for insulin differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 866.7 IU · L(-1) · 9 h(-1) (95% CI: 506.0, 1227.5 IU · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 542.0 IU · L(-1) · 9 h(-1) (95% CI: 179.9, 904.2 IU · L(-1) · 9 h(-1); P = 0.003) when compared with physical activity. Plasma glucose iAUC also differed between interventions (overall P < 0.001). Regular activity breaks lowered values by 18.9 mmol · L(-1) · 9 h(-1) (95% CI: 10.0, 28.0 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with prolonged sitting and by 17.4 mmol · L(-1) · 9 h(-1) (95% CI: 8.4, 26.3 mmol · L(-1) · 9 h(-1); P < 0.001) when compared with physical activity. Plasma triglyceride iAUC differed between interventions (overall P = 0.023). Physical activity lowered values by 6.3 mmol · L(-1) · 9 h(-1) (95% CI: 1.8, 10.7 mmol · L(-1) · 9 h(-1); P = 0.006) when compared with regular activity breaks. CONCLUSION: Regular activity breaks were more effective than continuous physical activity at decreasing postprandial glycemia and insulinemia in healthy, normal-weight adults. This trial was registered with the Australian New Zealand Clinical Trials registry as ACTRN12610000953033.


Assuntos
Glicemia/análise , Exercício Físico , Período Pós-Prandial , Comportamento Sedentário , Adulto , Área Sob a Curva , Bebidas , Índice de Massa Corporal , Doenças Cardiovasculares/prevenção & controle , Estudos Cross-Over , Dieta , Feminino , Humanos , Insulina/sangue , Masculino , Nova Zelândia , Fatores de Risco , Fatores de Tempo , Triglicerídeos/sangue , Caminhada , Adulto Jovem
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