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Stable isotopes have been used as tracers in human nutritional studies for many years. A number of isotopes have been used frequently to assess body composition, energy expenditure, protein turnover and metabolic studies in general, such as deuterium (.sup.2Hydrogen), .sup.18Oxygen, .sup.13Carbon and .sup.15Nitrogen. Nevertheless, there is still occasional confusion and concern over their safety, which can hinder the appropriate use of these isotopes in human studies. This mini review aims, therefore, to consider the safety of the four stable isotopes mentioned above, and to reiterate and reaffirm their safety once again. It is hoped that these data will be of use to new researchers in the field, as well as those considering the ethical or other implications of using these stable isotopes in nutritional research. Undoubtedly some of the confusion arises as deuterium, especially, is associated with the nuclear industry. However, as their name implies, of course, none of these stable isotopes are radioactive, and no adverse biological or physiological effects have been reported at the very low levels of enrichment that are used in human studies. There are ample data to reaffirm the safety of stable isotopes at the levels used in nutritional research, and unnecessary concerns and/or confusion should not be a block to continued use of these important tracers., Author(s): Peter S. W. Davies [sup.1] Author Affiliations: (1) Child Health Research Centre Level 6, Centre for Children's Health Centre, University of Queensland, South Brisbane, Australia Introduction At the time [...]

Background Until recently, pediatric body composition reference data were very limited, hindering interpretation of measurements. In the last decade, such data emerged for several techniques for children [greater than or equal to] 5 years, but equivalent data for younger age groups remain lacking, due to their poor compliance with most techniques. Objectives To provide reference data for use in clinical practice and research from 6 weeks to 5 years, that are based on measurements of total body water (TBW) by isotope dilution. Design The data on anthropometry and TBW were available from studies of 463 infants and children aged 6 weeks to 7 years, conducted between 1988 and 2010. Both breast-fed and formula-fed infants were included. TBW was measured by .sup.2H- or .sup.18O-labeled water, and converted to fat-free mass (FFM) using published hydration coefficients. Reference charts and SD scores (SDS) were constructed for FFM, fat mass (FM), FFM index and FM index for each sex, using the lambda-mu-sigma method. Results Both sexes were significantly heavier and longer than UK 1990 reference data (p < 0.01), but did not differ in body mass index SDS. Breast-fed infants were longer than formula-fed infants but did not differ in body composition. Conclusions These reference data will enhance the ability of clinicians to assess and monitor body composition and FFM/FM accretion in clinical practice in younger age groups. Total body water can be measured in most patients, though abnormalities of hydration must be addressed. However, the centiles do not overlap exactly with those published for older age groups, limiting comparability between younger and older children., Author(s): Jonathan C. K. Wells [sup.1] [sup.2] , Peter S. W. Davies [sup.3] , Mary S. Fewtrell [sup.1] [sup.2] , Tim J. Cole [sup.2] Author Affiliations: (1) Childhood Nutrition Research [...]

Introduction Obesity is a global problem that is challenging to prevent and expensive to treat. Early childhood interventions show promise in establishing lifelong healthy eating patterns, however a better understanding of how parental feeding practices develop is needed. The study aimed to investigate maternal perception of infant weight and its relationship to feeding practices and infant dietary intake. Methods A questionnaire was completed by 263 Queensland mothers of infants aged between 5 and 13 months. Logistic regression was used to describe the association between maternal feeding practices (restriction, pressure-to-eat, monitoring), parenting style (warmth, hostility), infant weight concern and infant dietary intake. Correlation and linear regression were used to identify relationships between maternal feeding practices, parenting style, infant weight concern and infant weight. Results Mothers were found to be more concerned about underweight than overweight, misjudge infants as being underweight and failed to recognise overweight infants. Underweight concern was associated with infant weight (r = -0.27, p < 0.01), early introduction of solids (OR 0.24, CI 0.11-0.51) and pressure-to-eat (r = 0.19, p < 0.01). Pressure-to-eat was associated to maternal perception of infant weight (r = - 0.21, p < 0.01), infant weight (r = - 0.17, p < 0.05) and lower fruit and vegetable intake (OR 0.50, CI 0.27-0.92). Restrictive feeding practices were correlated to overweight concern (r = 0.08, p < 0.05). Discussion Maternal infant weight perception and concerns are related to control feeding practices which can be detrimental to infant dietary intake. Inability to recognise healthy weight may ignite these concerns or fail to address infant feeding risk factors. Discussing healthy growth should be a fundamental component of strategies to support healthy infant feeding and eating., Author(s): Michelle Harrison [sup.1] , Wendy Brodribb [sup.2] , Peter S. W. Davies [sup.3] , Julie Hepworth [sup.4] Author Affiliations: (Aff1) 0000 0000 9320 7537, grid.1003.2, Primary Care Clinical Unit [...]

This study found that the physical activity levels of 10 children with Prader-Willi syndrome were significantly reduced in comparison to children without the syndrome. Increasing activity levels in children with Prader-Willi syndrome is suggested as a way to raise total energy expenditure and control weight gain. (Author/JDD)

Purpose: Poor cardiorespiratory fitness is associated with increased all cause morbidity and mortality. In children with obesity, maximum oxygen uptake (...O2max) may not be achieved due to reduced motivation and peripheral fatigue. We aimed to identify a valid submaximal surrogate for ...O2max in children with obesity. Method: Ninety-two children with obesity (7-16 years) completed a maximal exercise treadmill test and entered a three-month exercise and/or nutrition intervention after which the exercise test was repeated (n = 63). Participants were required to reach ...O2max to be included in this analysis (n = 32 at baseline and n = 13 at both time-points). The oxygen uptake efficiency slope (OUES) was determined as the slope of the line when ...O2 (L/min) was plotted against log...E. Associations between the maximal OUES, submaximal OUES (at 3, 4, 5 and 6 min of the exercise test) and ...O2max were calculated. Results: In the cross-sectional analysis, ...O2max (L/min) was strongly correlated with 5-min OUES independent of Tanner puberty stage and sex (R² = .80, p < .001). Longitudinal changes in ...O2max were closely reflected by changes in 5-min OUES independent of change in percent body fat (R² = .63, p < .05). Conclusion: The 5-min OUES is a viable alternative to ...O2max when assessing children with obesity. [ABSTRACT FROM AUTHOR]