J M W Wallace

University of Ulster, Belfast, NIR, United Kingdom

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Publications (27)70.92 Total impact

  • Article: Family eating out-of-home: a review of nutrition and health policies.
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    ABSTRACT: Childhood obesity is a growing problem worldwide. In recent years, out-of-home (OH) eating has been highlighted as one of the many factors contributing to the obesogenic environment. This review seeks to identify a range of existing guidelines for the provision of healthy food options for families who eat OH frequently. Nationally available nutrition policies were identified using targeted and untargeted searches of the internet to identify established strategies for providing food for children in the family eating out sector in America (US), Australia, Canada and the WHO's European Region (EUR). These were categorised on the basis of eleven pre-defined criteria including: family eating out sector included as stakeholder; inclusion of children's food OH; cost strategies for healthier food choices; provision of nutrition information for customers; nutrition training of catering staff; and monitoring and evaluation structures. Fifty-five policies were reviewed, of which 71% addressed children's food served OH, but principally only for food available in schools. Two voluntary programmes, from Colorado and Slovenia, were identified as possible best practice models as they met a majority of the evaluation criteria. The most frequently used strategy by policies to promote healthier eating OH was the provision of nutrition information on menus, while monitoring and evaluation plans were poorly incorporated into any OH strategies, thus raising issues about their effectiveness. This review has identified a range of initiatives that could be employed to make healthier eating OH more accessible for families. However, to establish best practice guidelines for healthier OH food choices further investigations are required.
    Proceedings of The Nutrition Society 11/2012; · 2.77 Impact Factor
  • Article: Serving size guidance for consumers: is it effective?
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    ABSTRACT: Larger portion sizes (PS) may be inciting over-eating and contributing to obesity rates. Currently, there is a paucity of data on the effectiveness of serving size (SS) guidance. The aims of the present review are to evaluate SS guidance; the understanding, usability and acceptability of such guidance, its impact on consumers and potential barriers to its uptake. A sample of worldwide SS guidance schemes (n 87) were identified using targeted and untargeted searches, overall these were found to communicate various inconsistent and often conflicting messages about PS selection. The available data suggest that consumers have difficulty in understanding terms such as 'portion size' and 'serving size', as these tend to be used interchangeably. In addition, discrepancies between recommended SS and those present on food labels add to the confusion. Consumers generally understand and visualise SS best when expressed in terms of household measures rather than actual weights. Only a limited number of studies have examined the direct impact of SS guidance on consumer behaviour with equivocal results. Although consumers recognise that guidance on selecting SS would be helpful, they are often unwilling to act on such guidance. The challenge of achieving consumer adherence to SS guidance is formidable due to several barriers including chronic exposure to larger PS, distorted consumption norms and perceptions, the habit of 'cleaning one's plate' and language barriers for ethnic minorities. In conclusion, the impact of SS guidance on consumers merits further investigation to ensure that future guidance resonates with consumers by being more understandable, usable and acceptable.
    Proceedings of The Nutrition Society 08/2012; 71(4):610-21. · 2.77 Impact Factor
  • Article: Endothelial dysfunction associated with obesity and the effect of weight loss interventions.
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    ABSTRACT: Endothelial damage is central to the initiation and progression of atherosclerosis, while in addition vascular endothelial cells secrete several anti-atherogenic substances including the potent vasodilator nitric oxide. Increased adhesion molecule expression, in response to pathophysiological stimuli is perhaps the earliest indicator of compromised endothelial integrity. Obesity and adiposity are associated with an increased risk of CVD, influencing disease progression via a number of mechanisms, including enhanced endothelial activation. This review discusses possible mechanisms linking adiposity and more specifically regional fat depots with endothelial function and evaluates studies investigating the effect of weight loss on endothelial function, assessed by biochemical and physiological measurements. Overall, the research to date suggests that visceral adiposity is a stronger predictor of endothelial activation than overall adiposity, possibly mediated via the action of NEFA in circulation. While in general there is a suggestion that weight loss is associated with significant improvements in endothelial function, this is not apparent in all interventions and published literature to date provides less than convincing evidence for the effects of weight loss on endothelial activation.
    Proceedings of The Nutrition Society 08/2011; 70(4):418-25. · 2.77 Impact Factor
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    Article: Red meat from animals offered a grass diet increases plasma and platelet n-3 PUFA in healthy consumers.
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    ABSTRACT: Red meat from grass-fed animals, compared with concentrate-fed animals, contains increased concentrations of long-chain (LC) n-3 PUFA. However, the effects of red meat consumption from grass-fed animals on consumer blood concentrations of LC n-3 PUFA are unknown. The aim of the present study was to compare the effects on plasma and platelet LC n-3 PUFA status of consuming red meat produced from either grass-fed animals or concentrate-fed animals. A randomised, double-blinded, dietary intervention study was carried out for 4 weeks on healthy subjects who replaced their habitual red meat intake with three portions per week of red meat (beef and lamb) from animals offered a finishing diet of either grass or concentrate (n 20 consumers). Plasma and platelet fatty acid composition, dietary intake, blood pressure, and serum lipids and lipoproteins were analysed at baseline and post-intervention. Dietary intakes of total n-3 PUFA, as well as plasma and platelet concentrations of LC n-3 PUFA, were significantly higher in those subjects who consumed red meat from grass-fed animals compared with those who consumed red meat from concentrate-fed animals (P < 0ยท05). No significant differences in concentrations of serum cholesterol, TAG or blood pressure were observed between groups. Consuming red meat from grass-fed animals compared with concentrate-fed animals as part of the habitual diet can significantly increase consumer plasma and platelet LC n-3 PUFA status. As a result, red meat from grass-fed animals may contribute to dietary intakes of LC n-3 PUFA in populations where red meat is habitually consumed.
    The British journal of nutrition 01/2011; 105(1):80-9. · 3.45 Impact Factor
  • Article: Prevalence of vitamin D deficiency and insufficiency in pregnant women: a longitudinal study
    Proceedings of The Nutrition Society 12/2009; 69. · 2.77 Impact Factor
  • Article: The relationship between gender and age with monocyte tissue factor expression.
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    ABSTRACT: In normal healthy individuals, the level of tissue factor (TF) expression on monocytes is low. However, studies have shown that patients with cardiovascular disease (CVD) have elevated levels of TF. As the risk of CVD increases with age and is more prominent in the male population, it is postulated that TF expression may be positively correlated with these factors. However, very few studies have examined the relationship between age and gender on TF expression. This study evaluated the influence of age and gender on TF expression using data obtained from female (n = 44) and male (n = 27) subjects. We also examined the influence of BMI and total fat intake on TF expression in the same subjects. The results of our study found no significant difference in TF expression between the male and female subgroups. No correlation was found between TF and age, BMI or total fat intake in the male or female groupings. It may be postulated that the risk of CVD development in such populations may not be due to increases in TF expression with increasing age or gender differences.
    Journal of Thrombosis and Thrombolysis 08/2009; 28(2):156-65. · 1.48 Impact Factor
  • Article: Comparison of the effects of four commercially available weight-loss programmes on lipid-based cardiovascular risk factors.
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    ABSTRACT: To investigate the relative efficacy of four popular weight-loss programmes on plasma lipids and lipoproteins as measures of CVD risk. A multi-centred, randomised, controlled trial of four diets - Dr Atkins' New Diet Revolution, The Slim-Fast Plan, Weight Watchers Pure Points programme and Rosemary Conley's 'Eat yourself Slim' Diet and Fitness Plan - against a control diet, in parallel for 6 months. The trial was conducted at five universities across the UK (Surrey, Nottingham, Ulster (Coleraine), Bristol and Edinburgh (Queen Margaret University College)) and involved the participation of 300 overweight and obese males and females aged 21-60 years in a community setting. Significant weight loss was achieved by all dieting groups (5-9 kg at 6 months) but no significant difference was observed between diets at 6 months. The Weight Watchers and Rosemary Conley (low-fat) diets were followed by significant reductions in plasma LDL cholesterol (both -12.2 % after 6 months, P < 0.01), whereas the Atkins (low-carbohydrate) and Weight Watchers diets were followed by marked reductions in plasma TAG (-38.2 % and -22.6 % at 6 months respectively, P < 0.01). These latter two diets were associated with an increase in LDL particle size, a change that has been linked to reduced CVD risk. Overall, these results demonstrate the favourable effects of weight loss on lipid-mediated CVD risk factors that can be achieved through commercially available weight-loss programmes. No detrimental effects on lipid-based CVD risk factors were observed in participants consuming a low-carbohydrate diet.
    Public Health Nutrition 06/2009; 12(6):799-807. · 2.17 Impact Factor
  • Article: Habitual fish consumption does not prevent a decrease in LCPUFA status in pregnant women (the Seychelles Child Development Nutrition Study).
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    ABSTRACT: Information on the status of long-chain polyunsaturated fatty acids (LCPUFAs) in pregnancy and breast milk in very high fish-eating populations is limited. The aim of this study was to examine dietary intake and changes in fatty acid status in a population of pregnant women in the Republic of Seychelles. Serum docosahexaenoic acid (DHA) decreased significantly between 28-week gestation and delivery (n=196). DHA status did not correlate significantly with length of gestation and was not associated with self-reported fish intake, which was high at 527 g/week. In breast milk, the ratio of DHA to arachidonic acid (AA) was consistent with those observed in other high fish-eating populations. Overall the data suggest that high exposure to LCPUFAs from habitual fish consumption does not prevent the documented decrease in LCPUFA status in pregnancy that occurs as a result of foetal accretion in the third trimester of pregnancy.
    Prostaglandins Leukotrienes and Essential Fatty Acids 07/2008; 78(6):343-50. · 3.37 Impact Factor
  • Article: The effect of nicotine in vitro on the integrity of tight junctions in Caco-2 cell monolayers.
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    ABSTRACT: Ulcerative colitis is characterised by impairment of the epithelial barrier and tight junction alterations resulting in increased intestinal permeability. UC is less common in smokers with smoking reported to decrease paracellular permeability. The aim of this study was thus to determine the effect of nicotine, the major constituent in cigarettes and its metabolites on the integrity of tight junctions in Caco-2 cell monolayers. The integrity of Caco-2 tight junctions was analysed by measuring the transepithelial electrical resistance (TER) and by tracing the flux of the fluorescent marker fluorescein, after treatment with various concentrations of nicotine or nicotine metabolites over 48 h. TER was significantly higher compared to the control for all concentrations of nicotine 0.01-10 microM at 48 h (p<0.001), and for 0.01 microM (p<0.001) and 0.1 microM and 10 microM nicotine (p < 0.01) at 12 and 24 h. The fluorescein flux results supported those of the TER assay. TER readings for all nicotine metabolites tested were also higher at 24 and 48 h only (p < or = 0.01). Western blot analysis demonstrated that nicotine up-regulated the expression of the tight junction proteins occludin and claudin-1 (p < or = 0.01). Overall, it appears that nicotine and its metabolites, at concentrations corresponding to those reported in the blood of smokers, can significantly improve tight junction integrity, and thus, decrease epithelial gut permeability. We have shown that in vitro, nicotine appears more potent than its metabolites in decreasing epithelial gut permeability. We speculate that this enhanced gut barrier may be the result of increased expression of claudin-1 and occludin proteins, which are associated with the formation of tight junctions. These findings may help explain the mechanism of action of nicotine treatment and indeed smoking in reducing epithelial gut permeability.
    Food and Chemical Toxicology 09/2007; 45(9):1593-8. · 3.00 Impact Factor
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    Article: Assessment of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D3 concentrations in male and female multiple sclerosis patients and control volunteers.
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    ABSTRACT: Populations with insufficient ultraviolet exposure and who consume diets low in vitamin D have low vitamin D status (plasma 25-hydroxyvitamin D (25(OH)D) concentrations) and a reported higher incidence of multiple sclerosis (MS). The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), is an effective anti-inflammatory molecule. No research to date has assessed 1,25(OH)2D3 concentrations in individuals with MS. In this study, plasma concentrations of 25(OH)D, 1,25(OH)2D3 and parathyroid hormone (PTH) were measured in 29 individuals with MS and 22 age- and sex-matched control volunteers. There were no significant differences in plasma PTH, 25(OH)D and 1,25(OH)2D3 concentrations between individuals with MS and control volunteers. Women with MS had significantly higher 25(OH)D and 1,25(OH)2D3 concentrations than men with MS (79.1+/-45.4 versus 50.2+/-15.3 nmol/L, P=0.019 and 103.8+/-36.8 versus 70.4+/-28.7 pmol/L, P=0.019, respectively). There was a significant positive correlation between 25(OH)D and 1,25(OH)2D3 concentrations in all subjects (r=0.564, P=0.000), but secondary analysis revealed that the correlation was driven by women with MS (r=0.677, P=0.001). Significant sex differences in vitamin D metabolism were observed and were most marked in individuals with MS, suggesting that vitamin D requirements may differ between the sexes, as well as by underlying disease state.
    Multiple Sclerosis 07/2007; 13(5):670-2. · 4.26 Impact Factor
  • Article: Assessment of 25-hydroxyvitamin D and1,25-dihydroxyvitamin D3 concentrations in maleand female multiple sclerosis patients and controlvolunteers
    Multiple Sclerosis 01/2007; 13:670-672. · 4.26 Impact Factor
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    Article: Investigation of the medium-term effects of Olibratrade mark fat emulsion on food intake in non-obese subjects.
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    ABSTRACT: To investigate the effect of Olibra fat emulsion on medium-term food intake and appetite in non-obese subjects. Double-blind, placebo-controlled, within-subject crossover. University of Ulster, Coleraine. A total of 28 subjects (14 male, 14 female). Subjects were randomly assigned to receive either a 200 g portion of test (5 g of Olibra fat) or control (5 g milk fat) yoghurt for breakfast for 2 x 3 week 'study' phases, separated by a 3-week 'wash-out' phase. On days 1, 8 and 22 of the study phases, food intake 4 h post-consumption of the yoghurt was assessed by pre- and post-covert weighing at an ad libitum buffet-style test lunch. Throughout each of these study days, appetite was assessed using visual analogue scales (VAS) at regular intervals. For the remainder of the study days, and the following 24 h ('post-study days'), subjects reported their food intake using weighed dietary records. Consumption of the Olibra emulsion had no significant effect on mean energy, macronutrient or amounts of food consumed at the lunch 4 h post-consumption. Self-reported food intakes indicated that there was no significant effect of the emulsion on energy intakes for the remainder of each study day and post-study days. There was considerable individual variation in food intakes following consumption of the Olibra emulsion, with 46, 59 and 57% of subjects reducing their energy intakes at lunch on days 1, 8 and 22. There was no consistent effect of the emulsion on appetite ratings. In contrast to earlier studies, there was no evidence of a short- or medium-term effect of the Olibra emulsion on food intake or appetite. This could be owing to numerous confounding factors influencing eating behaviour and/or the different study design used in the present study.
    European Journal of Clinical Nutrition 10/2006; 60(9):1081-91. · 2.46 Impact Factor
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    Article: Effect of vitamin D supplementation on vitamin D status and bone turnover markers in young adults.
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    ABSTRACT: To assess the vitamin D status of healthy young people living in Northern Ireland and the effect of vitamin D supplementation on vitamin D status and bone turnover. Double-blinded randomised controlled intervention study. University of Ulster, Coleraine, Northern Ireland. In total, 30 apparently healthy students (15 male and 15 female subjects), aged 18-27 years, were recruited from the university, with 27 completing the intervention. Subjects were randomly assigned, to receive either 15 microg (600 IU) vitamin D(3) and 1,500 mg calcium/day (vitamin D group), or 1,500 mg calcium/day (control group) for 8 weeks between January and March. Vitamin D status, bone turnover markers, serum calcium and parathyroid hormone concentrations were measured at baseline and post intervention. At baseline, vitamin D status was low in both the vitamin D group (47.9 (s.d. 16.0)) and the control group (55.5 (s.d. 18.6) nmol/l 25(OH)D). Post intervention vitamin D status was significantly higher in the vitamin D-treated group (86.5 (s.d. 24.5)) compared to the control group (48.3 (s.d. 16.8) nmol/l) (P<0.0001). There was no significant effect of supplementation on bone turnover markers or PTH concentrations. This study suggests that young adults in Northern Ireland do not consume an adequate daily dietary intake of vitamin D to maintain plasma vitamin D concentrations in the wintertime. A daily supplement of 15 microg vitamin D(3) significantly increased vitamin D status in these individuals to levels of sufficiency. Achievement of an optimum vitamin D status among young adults may have future positive health implications.
    European Journal of Clinical Nutrition 06/2006; 60(6):727-33. · 2.46 Impact Factor
  • Article: Zinc status and age-related changes in peripheral blood leukocyte subpopulations in healthy men and women aged 55-70 y: the ZENITH study.
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    ABSTRACT: To determine zinc status and age-related changes in the immune function of healthy late-middle-aged men and women (aged 55-70 y). Observational study. Population of Northern Ireland. Apparently healthy, free-living individuals (45 men, 48 women) aged 55-70 y. Zinc status markers were analysed by flame atomic absorption spectrometry and commercially available kits. Immune function was assessed by flow cytometry. Serum and erythrocyte zinc concentrations were 13.0 (s.d. 1.40) micromol/l and 222 (s.d. 48.2) micromol/l, respectively. Serum alkaline phosphatase (ALP) concentrations were 76.8 (s.d. 16.1) U/l; women showed significantly higher concentrations of ALP (P = 0.011). Women demonstrated (1) a significant inverse correlation in naive T lymphocytes, specifically naive T-helper lymphocytes (% expression, r = -0.364, P = 0.007 and absolute count, r = -0.275, P = 0.036) with age and (2) a significant positive correlation between late activation of T lymphocytes (% expression, r = 0.299, P = 0.019 and absolute count, r = 0.260, P = 0.039) with advancing age. Men demonstrated a significant positive correlation in the % expression of (CD3-/CD16+/CD56+) natural killer (NK) cells with age (r = 0.316, P = 0.017). Between the ages of 55 and 70 y, healthy individuals experience significant alterations in immune function; however, such changes appear largely sex specific. Given the reported importance of adequate zinc status in maintaining optimal immune function, further studies are required to explore the effect of enhanced zinc status on emerging immune deficiencies in cell-mediated immunity in healthy 55-70 y olds.
    European Journal of Clinical Nutrition 12/2005; 59 Suppl 2:S63-7. · 2.46 Impact Factor
  • Article: Health and lifestyle characteristics of older European adults: the ZENITH study.
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    ABSTRACT: To describe health and lifestyle factors of participants in the ZENITH study. A prospective multicentre intervention study employing a randomised double-blind design. Community dwelling older adults (n = 387), aged 55-87 y were recruited from regions in France, Italy and the UK. A self-report questionnaire comprising socio-demographic variables, dietary habits, physical activity in the home, at work and recreation. Participants differed with regards dietary habits and physical activity for each region. Recreational activity was higher in France and women generally tend to perform less hours of recreational activity per week than men. The differences found for these regions of Europe in relation to lifestyle factors will affect health and well-being within these countries and may mediate the impact of zinc supplementation on various biological and psychological parameters.
    European Journal of Clinical Nutrition 12/2005; 59 Suppl 2:S13-21. · 2.46 Impact Factor
  • Article: Health and lifestyle characteristics of older European adults: the ZENITH study
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    ABSTRACT: Objective: To describe health and lifestyle factors of participants in the ZENITH study.
    European Journal of Clinical Nutrition 10/2005; · 2.46 Impact Factor
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    Article: Haemostasis in normal pregnancy: a balancing act?
    V A Holmes, J M W Wallace
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    ABSTRACT: Pregnancy is a risk factor for venous thrombosis and the incidence of venous thromboembolism during normal pregnancy is 6-fold higher during pregnancy than in the general female population of child-bearing age. This incidence is, however, remarkably low given the increases in markers of haemostatic activation observed during normal pregnancy. During normal healthy pregnancy there are substantial changes in the haemostatic system, many of which are procoagulant and supposed to be in preparation for the haemostatic challenge of delivery. Normal haemostasis requires a balance between coagulation and fibrinolysis to maintain the integrity of the vasculature, and complex physiological changes are evident during pregnancy which appear to ensure a constant coagulation/fibrinolysis balance. This balance is maintained, at least partly, by an increase in fibrinolytic activity, but decreases in other factors such as factor XI and monocyte tissue factor expression may also serve to counterbalance procoagulant changes.
    Biochemical Society Transactions 05/2005; 33(Pt 2):428-32. · 3.71 Impact Factor
  • Article: It's good to talk: children's views on food and nutrition.
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    ABSTRACT: To gain an insight into children's views about food and nutrition. Data were collected in focus group discussions; two focus group sessions were undertaken with each school group. A total of 11 postprimary schools in Northern Ireland and England. In all, 106 children aged 11-12-y-old (n = 52 boys, n = 54 girls). Focus group transcripts were analysed using qualitative research methodology. Major barriers to healthy eating were taste, appearance of food, filling power, time/effort, cost, choice/availability, risk, rebellion, and body image/weight concerns. The main difference between sexes was in terms of motivating factors for eating well; girls tended to focus primarily on their appearance whereas boys appeared to be more influenced by sport. There was some mention of balance and variety within the focus group discussions, however, in practice, the children had a tendency to categorise foods as either 'good' or 'bad', 'healthy' or 'unhealthy'. This study has revealed a number of barriers to, and motivations for, healthy eating, which should be taken into account when planning nutrition intervention strategies aimed at children moving into adolescence. While it may be possible to immediately attempt to address some of the barriers identified in this study, for example, in nutrition education initiatives, other barriers (such as the lack of available, attractive and affordable healthy foods in the school canteen) will prove more difficult to tackle without changes at the policy level. Overall, it appears that health promotion specialists have a major challenge ahead in order to encourage this age group to view healthy eating as an attractive and achievable behaviour. Food Standards Agency, London, UK.
    European Journal of Clinical Nutrition 05/2005; 59(4):542-51. · 2.46 Impact Factor
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    Article: Issues in dietary intake assessment of children and adolescents.
    M B E Livingstone, P J Robson, J M W Wallace
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    ABSTRACT: Studies of food habits and dietary intakes face a number of unique respondent and observer considerations at different stages from early childhood to late adolescence. Despite this, intakes have often been reported as if valid, and the interpretation of links between intake and health has been based, often erroneously, on the assumption of validity. However, validation studies of energy intake data have led to the widespread recognition that much of the dietary data on children and adolescents is prone to reporting error, mostly through under-reporting. Reporting error is influenced by body weight status and does not occur systematically across different age groups or different dietary survey techniques. It appears that the available methods for assessing the dietary intakes of children are, at best, able to provide unbiased estimates of energy intake only at the group level, while the food intake data of most adolescents are particularly prone to reporting error at both the group and the individual level. Moreover, evidence for the existence of subject-specific responding in dietary assessments challenges the assumption that repeated measurements of dietary intake will eventually obtain valid data. Only limited progress has been made in understanding the variables associated with misreporting in these age groups, the associated biases in estimating nutrient intakes and the most appropriate way to interpret unrepresentative dietary data. Until these issues are better understood, researchers should exercise considerable caution when evaluating all such data.
    British Journal Of Nutrition 11/2004; 92 Suppl 2:S213-22. · 3.01 Impact Factor
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    Article: How active are we? Levels of routine physical activity in children and adults.
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    ABSTRACT: The accurate measurement of physical activity is fraught with problems in adults, but more especially in children because they have more complex and multi-dimensional activity patterns. In addition, the results of different studies are often difficult to interpret and compare, because of the diversity of methodological approaches, differences in data analysis and reporting, and the adoption of varying definitions of what constitutes an appropriate level of activity. Furthermore, inactivity is seldom quantified directly. Although there exists an extensive literature documenting the health benefits of regular physical activity in adults, activity-health relationships in children are not clear-cut. Current recommendations reinforce the concept of health-related activity, accumulating 30 min moderate-intensity exercise on at least 5 d/week (adults) and 1 h moderate-intensity exercise/d (children). Evidence suggests a high prevalence of inactivity in adults, but whether or not inactivity is increasing cannot be assessed currently. Similarly, no definite conclusions are justified about either the levels of physical activity of children, or whether these are sufficient to maintain and promote health. Data to support the belief that activity levels in childhood track into adulthood are weak. Inactivity is associated with an increased risk of weight gain and obesity, but causality remains to be established. In children there is strong evidence to demonstrate a dose response relationship between the prevalence and incidence of obesity and time spent viewing television. Future research should focus on refining methodology for physical activity assessment to make it more sensitive to the different dimensions and contexts of activity in different age-groups.
    Proceedings of The Nutrition Society 09/2003; 62(3):681-701. · 2.77 Impact Factor