Errors in the implementation, analysis, and reporting of randomization within obesity and nutrition research: a guide to their avoidance.

Randomization is an important tool used to establish causal inferences in studies designed to further our understanding of questions related to obesity and nutrition. To take advantage of the inferences afforded by randomization, scientific standards must be upheld during the planning, execution, analysis, and reporting of such studies. We discuss ten errors in randomized experiments from real-world examples from the literature and outline best practices for their avoidance. These ten errors include: representing nonrandom allocation as random, failing to adequately conceal allocation, not accounting for changing allocation ratios, replacing subjects in nonrandom ways, failing to account for non-independence, drawing inferences by comparing statistical significance from within-group comparisons instead of between-groups, pooling data and breaking the randomized design, failing to account for missing data, failing to report sufficient information to understand study methods, and failing to frame the causal question as testing the randomized assignment per se. We hope that these examples will aid researchers, reviewers, journal editors, and other readers to endeavor to a high standard of scientific rigor in randomized experiments within obesity and nutrition research.

Roles and competencies in the nutritional domain for the management of the metabolic diseases and in the hospital setting: A position paper of the Italian College of Academic Nutritionists, MED-49 (ICAN-49).

Epidemiological evidence has confirmed the potential causal relationship between specific dietary factors and non-communicable diseases. However, currently nutrition was shown to be insufficiently integrated into medical education, regardless of the country. Without an adequate nutrition education, it is reasonable to assume that future physicians, as well as other health care professionals, will be not able to provide the highest quality care to patients in preventing and treating non-communicable diseases. Furthermore, the insufficient availability of physicians with specializations in nutrition has posed the basis for the development of non-medical careers in the field of nutrition. The present document was drafting by the Italian College of Academic Nutritionists, MED-49 (ICAN-49), with the aim to provide an overview on the nutritional competency standards covered by several health care professionals (Physicians Clinical Nutrition Specialists, Clinical Dietitians, Professional Clinical Nutrition Specialists, etc) for the prevention of diseases and/or support of pharmacological therapies. The aim of the ICAN 49 is to suggest a major shift in practice opportunities and roles for many nutritionists, especially for the management of the metabolic diseases, and promote a paradigm change: a clinical and educational leadership role for Physician Clinical Nutrition Specialists in the hospital setting.

A peer evaluation training results in high-quality feedback, as measured over time in nutritional sciences graduate students.

Peer evaluation skills are not typically taught to students, yet they are expected to provide high-quality feedback to their peers. Gameful learning, a pedagogy supporting student-driven learning, can further reinforce the development of peer evaluation skills, if students are motivated to improve upon them. To better understand the effects of a peer evaluation training on the quality of student-generated peer evaluations, we scored peer evaluations from two cohorts taking a graduate-level nutritional sciences class using gameful learning pedagogy. The intervention group completed a peer evaluation training before engaging in peer reviews, while the control group did not. The training included two readings, a video, and reflection questions. The peer evaluations submitted by both the intervention and control groups were assessed on a validated rubric. The peer evaluation training had a positive effect on the quality of the submitted peer evaluations. The intervention group had a 10.8% higher score on its first submitted peer evaluation compared with controls (P = 0.003). The intervention group improved the quality of its future submissions by a further 8.9%, whereas the controls did not continue to improve substantially (P < 0.001). Overall, peer review training enhanced the quality of peer evaluations and allowed students to develop professional skills that they can utilize in any biomedical profession. Our results highlight the importance of peer evaluation training in combination with repeated practice and student-driven learning brought forth by gameful learning pedagogy in improving the quality of evaluations and developing professional skills.

Prospective Evaluation of the ESPGHAN Guidelines for Diagnosis of Celiac Disease in New Zealand Children.

OBJECTIVE: The 2012 European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guideline for diagnosis of celiac disease (CD) questioned the requirement for intestinal biopsy to confirm the diagnosis. The guideline recommends that in symptomatic patients with consistent human leukocyte antigen (HLA) subtypes, the diagnostic accuracy of strongly positive serology is sufficient to confirm the diagnosis. We prospectively assessed these guidelines in a "real-life" clinical setting. METHODS: One hundred and four children referred for evaluation of possible CD were prospectively recruited. Following informed consent, blood was drawn for serological testing and HLA analysis at upper gastrointestinal endoscopy. Histological findings according to Marsh criteria were correlated with blood results and the accuracy of the guideline analyzed.The study also examined the role of deamidated gliadin peptide (DGP) in the diagnosis of CD. RESULTS: For symptomatic patients with consistent HLA subtypes, strongly positive serology (as described in the ESPGHAN guidelines) accurately predicted biopsy-proven CD in >95% of cases. DGP was positive in fewer patients than anti-TG2 or EMA. Incorporation of DGP as a second confirmatory serological test in place of EMA was associated with maintained predictive value of guideline, but fewer patients fulfilling criteria for biopsy-free diagnosis. CONCLUSIONS: The ESPGHAN guideline performs well in our population. Adoption of the guideline would reduce the number of patients requiring endoscopy without compromise in diagnostic accuracy. The involvement of pediatric gastroenterological expertise, however, remains key to diagnosis of CD.

National Institute of Nutrition: 100 years of empowering the nation through nutrition.

The National Institute of Nutrition (NIN) has reached a remarkable milestone of completing 100 years of exemplary service to the nation. The long journey that started in a humble one-room laboratory at Coonoor (now in Tamil Nadu) in 1918 to a colossus of the nutrition research in the country today is dotted with several interesting vignettes. The NIN has always been at the forefront of need-based, pragmatic research. Its large-scale community-based interventions have been of great practical value in the nation's fight against malnutrition. The evolution of nutrition as a modern science almost coincides with the growth of the Institute. Being the oldest in the fraternity of institutes under the Indian Council of Medical Research (ICMR), the NIN has grown from strength to strength due to the sheer relevance of its contributions in furthering nutrition science and promoting public health in the country. This article provides a historical overview of the evolution and contributions of ICMR-NIN in the areas of nutrition, food safety, public health and policy.

Why nutrition education is inadequate in the medical curriculum: a qualitative study of students' perspectives on barriers and strategies.

BACKGROUND: The provision of nutrition care by doctors is important in promoting healthy dietary habits, and such interventions can lead to reductions in disease morbidity, mortality, and medical costs. However, medical students and doctors report inadequate nutrition education and preparedness during their training at school. Previous studies investigating the inadequacy of nutrition education have not sufficiently evaluated the perspectives of students. In this study, students' perspectives on doctors' role in nutrition care, perceived barriers, and strategies to improve nutrition educational experiences are explored. METHODS: A total of 23 undergraduate clinical level medical students at the 5th to final year in the School of Medicine and Health Sciences of the University for Development Studies in Ghana were purposefully selected to participate in semi-structured individual interviews. Students expressed their opinions and experiences regarding the inadequacy of nutrition education in the curriculum. Each interview was audio-recorded and later transcribed verbatim. Using the constant comparison method, key themes were identified from the data and analysis was done simultaneously with data collection. RESULTS: Students opined that doctors have an important role to play in providing nutrition care to their patients. However, they felt their nutrition education was inadequate due to lack of priority for nutrition education, lack of faculty to provide nutrition education, poor application of nutrition science to clinical practice and poor collaboration with nutrition professionals. Students opined that their nutrition educational experiences will be improved if the following strategies were implemented: adoption of innovative teaching and learning strategies, early and comprehensive incorporation of nutrition as a theme throughout the curriculum, increasing awareness on the importance of nutrition education, reviewing and revision of the curriculum to incorporate nutrition, and involving nutrition/dietician specialists in medical education. CONCLUSION: Though students considered nutrition care as an important role for doctors they felt incapacitated by non-prioritisation of nutrition education, lack of faculty for teaching of nutrition education, poor application of nutrition science and poor collaboration with nutrition professionals. Incorporation of nutrition as a theme in medical education, improving collaboration, advocacy and creating enabling environments for nutrition education could address some of the barriers to nutrition education.

Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition.

BACKGROUND: Interest in vegetarian diets is growing in Italy and elsewhere, as government agencies and health/nutrition organizations are emphasizing that regular consumption of plant foods may provide health benefits and help prevent certain diseases. METHODS AND RESULTS: We conducted a Pubmed search, up to September, 2015, for studies on key nutrients (proteins, vitamin B12, iron, zinc, calcium, vitamin D, and n-3 fatty acids) in vegetarian diets. From 295 eligible publications the following emerged: Vegetarians should be encouraged to supplement their diets with a reliable source of vitamin B12 (vitamin-fortified foods or supplements). Since the plant protein digestibility is lower than that of animal proteins it may be appropriate for vegetarians to consume more proteins than recommended for the general population. Vegetarians should also be encouraged to habitually consume good sources of calcium, iron and zinc - particularly vegetables that are low in oxalate and phytate (e.g. Brassicaceae), nuts and seeds, and calcium-rich mineral water. Calcium, iron, and zinc bioavailability can be improved by soaking, germination, and sour-dough leavening that lower the phytate content of pulses and cereals. Vegetarians can ensure good n-3 fatty acid status by habitually consuming good sources of a-linolenic acid (walnuts, flaxseeds, chia seeds, and their oils) and limiting linoleic acid intake (corn and sunflower oils). CONCLUSIONS: Well-planned vegetarian diets that include a wide variety of plant foods, and a reliable source of vitamin B12, provide adequate nutrient intake. Government agencies and health/nutrition organizations should provide more educational resources to help Italians consume nutritionally adequate vegetarian diets.

Personal Trainer Perceptions of Providing Nutrition Care to Clients: A Qualitative Exploration.

Personal trainers are well placed to provide basic nutrition care in line with national dietary guidelines. However, many personal trainers provide nutrition care beyond their scope of practice and this has been identified as a major industry risk due to a perceived lack of competence in nutrition. This paper explores the context in which personal trainers provide nutrition care, by understanding personal trainers' perceptions of nutrition care in relation to their role and scope of practice. Semistructured telephone interviews were conducted with 15 personal trainers working within Australia. Thematic analysis was used to identify key themes. All personal trainers reported to provide nutrition care and reported that nutrition care was an important component of their role. Despite this, many were unaware or uncertain of the scope of practice for personal trainers. Some personal trainers reported a gap between the nutrition knowledge they received in their formal education, and the knowledge they needed to optimally support their clients to adopt healthy dietary behaviors. Overall, the personal training context is likely to be conducive to providing nutrition care. Despite concerns about competence personal trainers have not modified their nutrition care practices. To ensure personal trainers provide nutrition care in a safe and effective manner, greater enforcement of the scope of practice is required as well as clear nutrition competencies or standards to be developed during training.

Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement.

BACKGROUND: Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut). METHODS AND FINDINGS: Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist. CONCLUSION: When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health.

The importance of prediction model validation and assessment in obesity and nutrition research.

Deriving statistical models to predict one variable from one or more other variables, or predictive modeling, is an important activity in obesity and nutrition research. To determine the quality of the model, it is necessary to quantify and report the predictive validity of the derived models. Conducting validation of the predictive measures provides essential information to the research community about the model. Unfortunately, many articles fail to account for the nearly inevitable reduction in predictive ability that occurs when a model derived on one data set is applied to a new data set. Under some circumstances, the predictive validity can be reduced to nearly zero. In this overview, we explain why reductions in predictive validity occur, define the metrics commonly used to estimate the predictive validity of a model (for example, coefficient of determination (R(2)), mean squared error, sensitivity, specificity, receiver operating characteristic and concordance index) and describe methods to estimate the predictive validity (for example, cross-validation, bootstrap, and adjusted and shrunken R(2)). We emphasize that methods for estimating the expected reduction in predictive ability of a model in new samples are available and this expected reduction should always be reported when new predictive models are introduced.

The use of different reference foods in determining the glycemic index of starchy and non-starchy test foods.

BACKGROUND: Glycemic index (GI) is intended to be a property of food but some reports are suggestive that GI is influenced by participant characteristics when glucose is used as a reference. OBJECTIVE: To examine the influence of different reference foods on observed GI. DESIGN: The GIs of five varieties of rice and a sugary beverage (LoGiCane™) were tested in 31 European and 32 Chinese participants using glucose or jasmine rice as reference foods. The GIs of two ready-to-eat breakfast cereals (Kellogg's cornflakes and Sustain) were tested in 20 younger and 60 older people using glucose or Sustain as reference foods. RESULTS: The GIs of rice tended to be higher in the Chinese compared with the Europeans when glucose was used as a reference (jasmine 80 vs 68, P = 0.033; basmati 67 vs 57, P = 0.170; brown 78 vs 65, P = 0.054; Doongara 67 vs 55, P = 0.045; parboiled 72 vs 57, P = 0.011). There were no between-group differences in GI when jasmine rice was the reference. The GIs of breakfast cereals tended to be lower in younger compared with older groups (cornflakes 64 vs 81, P = 0.008; Sustain 56 vs 66, P = 0.054). There was no between-group difference in the GI of cornflakes when Sustain was the reference (cornflakes 115 vs 120, P = 0.64). There was no ethnic difference in GI when glucose was the reference for another sugary food (LoGiCane™ 60 vs 62; P = 0.69). CONCLUSIONS: A starchy reference may be more appropriate than a glucose beverage when attempting to derive universally applicable GI values of starchy foods. TRIAL REGISTRATION: The Chinese/European trial is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12612000519853.

An evidence-based method for examining and reporting cognitive processes in nutrition research.

Cognitive outcomes are frequently implemented as endpoints in nutrition research. To reduce the number of statistical comparisons it is commonplace for nutrition researchers to combine cognitive test results into a smaller number of broad cognitive abilities. However, there is a clear lack of understanding and consensus as to how best execute this practice. The present paper reviews contemporary models of human cognition and proposes a standardised, evidence-based method for grouping cognitive test data into broader cognitive abilities. Both Carroll's model of human cognitive ability and the Cattell-Horn-Carroll (CHC) model of intelligence provide empirically based taxonomies of human cognition. These models provide a cognitive 'map' that can be used to guide the handling and analysis of cognitive outcomes in nutrition research. Making use of a valid cognitive nomenclature can provide the field of clinical nutrition with a common cognitive language enabling efficient comparisons of cognitive outcomes across studies. This will make it easier for researchers, policymakers and readers to interpret and compare cognitive outcomes for different interventions. Using an empirically derived cognitive nomenclature to guide the creation of cognitive composite scores will ensure that cognitive endpoints are theoretically valid and meaningful. This will increase the generalisability of trial results to the general population. The present review also discusses how the CHC model of cognition can also guide the synthesis of cognitive outcomes in systematic reviews and meta-analysis.

Barriers and Opportunities for Clinical Nutritionists in 13 Latin American Countries: A Qualitative Study.

A clinical nutritionist (CN) is a university-educated professional trained to perform preventive and recovery functions in the health of patients. The actions of these professionals, both worldwide and in Latin America, may face barriers and opportunities that require careful identification and examination. The main objective of this study is to identify the most important barriers and opportunities for the clinical nutritionist in 13 Latin American countries. A qualitative study was carried out; the initial phase involved conducting in-depth individual interviews with 89 informants, experienced CNs from 13 Latin American countries. After calculating the mean and standard deviation, we ranked the top 10 most frequently reported barriers by assigning a score ranging from 1 to 10. Additionally, 3 opportunities were identified with a lower score from 1 to 3. Means and standard deviation were calculated to sort the responses. Results: the most important barrier was the absence of public policies that regulate and/or monitor compliance with the staffing of CNs according to the number of hospital beds, while the most important opportunity was the advances in technology such as software, body analysis equipment and other tools used in Nutritional Care. The identified barriers can interfere with the professional performance of CNs and, moreover, make it difficult to monitor the good nutritional status of patients. It is recommended to consider the barriers identified in this study, as well as the opportunities, with a view to improving the quality of hospital services with an adequate supply of nutritionists.

Systematic reviews in nutrition: standardized methodology.

The objective of this study is to establish a methodological proposal in order to carry out qualitative systematic reviews and apply these findings to a review of Omega-3 Fatty Acids with respect to health and illness. Based on a methodological proposal, a general protocol was developed to provide a sound basis for the preparation of the reviews in this journal supplement. A systematic technique was proposed in order to revise the existing scientific literature on Omega-3 Fatty Acids, with particular emphasis on aspects relating to health and illness. The aim of qualitative systematic reviews is to collate and summarise the results of the primary studies reviewed which will be carried out through a descriptive synthesis. It can be concluded that systematic reviews provide a summary of the existing primary documents on a specific scientific question. The detailed and explicit methods used lead to the identification, critical evaluation and synthesis of the scientific literature. Furthermore, both bias and random effects are reduced, resulting in more reliable data from which to draw conclusions and make recommendations to support decision-making.

The making of a nutrition professional: the Association for Nutrition register.

OBJECTIVE: Nutritionists in the UK are at the start of an exciting time of professional development. The establishment of the Association for Nutrition in 2010 has presented an opportunity to review, revitalize and expand the UK Voluntary Register of Nutritionists. In the UK and elsewhere, there is a need for a specialist register of nutritionists with title protection as a public safeguard. DESIGN: The new structure will base professional registration on demonstration of knowledge and application in five core competencies. Initially, there will be five specialist areas: animal; public health; nutritional scientist; food; sports and exercise. The wording and requirements linking the specialist areas to the competencies have been carefully defined by leading individuals currently on the existing register in these specialist areas. These have been evaluated by a random sample of existing registrants to check for accuracy of definitions and examples. Other work aims to establish a clear quality assurance framework in nutrition for workers in the health and social care sectors (UK Public Health Skills and Career Framework Levels 1-4) who contribute to nutrition activity, such as community food workers, nutrition assistants and pharmacists. Students, co-professional affiliates and senior fellows will also find a place in the new Association. The title 'nutritionist' is not currently legally protected in the UK and it is used freely to cover a range of unregulated practice. CONCLUSIONS: The establishment of a professional register to protect the public and to provide a clear identity for nutritionists is a vital step forward.

NUQUEST-NUtrition QUality Evaluation Strengthening Tools: development of tools for the evaluation of risk of bias in nutrition studies.

BACKGROUND: Dietary exposure assessments are a critical issue in evaluating human nutrition studies; however, nutrition-specific criteria are not consistently included in existing bias assessment tools. OBJECTIVES: Our objective was to develop a set of risk of bias (RoB) tools that integrated nutrition-specific criteria into validated generic assessment tools to address RoB issues, including those specific to dietary exposure assessment. METHODS: The Nutrition QUality Evaluation Strengthening Tools (NUQUEST) development and validation process included 8 steps. The first steps identified 1) a development strategy; 2) generic assessment tools with demonstrated validity; and 3) nutrition-specific appraisal issues. This was followed by 4) generation of nutrition-specific items and 5) development of guidance to aid users of NUQUEST. The final steps used established ratings of selected studies and feedback from independent raters to 6) assess reliability and validity; 7) assess formatting and usability; and 8) finalize NUQUEST. RESULTS: NUQUEST is based on the Scottish Intercollegiate Guidelines Network checklists for randomized controlled trials, cohort studies, and case-control studies. Using a purposive sample of 45 studies representing the 3 study designs, interrater reliability was high (Cohen's κ: 0.73; 95% CI: 0.52, 0.93) across all tools and at least moderate for individual tools (range: 0.57-1.00). The use of a worksheet improved usability and consistency of overall interrater agreement across all study designs (40% without worksheet, 80%-100% with worksheet). When compared to published ratings, NUQUEST ratings for evaluated studies demonstrated high concurrent validity (93% perfect or near-perfect agreement). Where there was disagreement, the nutrition-specific component was a contributing factor in discerning exposure methodological issues. CONCLUSIONS: NUQUEST integrates nutrition-specific criteria with generic criteria from assessment tools with demonstrated reliability and validity. NUQUEST represents a consistent and transparent approach for evaluating RoB issues related to dietary exposure assessment commonly encountered in human nutrition studies.