Nutrients

Research

14 pages, 1057 KiB

Open AccessArticle

A Meta-Epidemiological Study of Positive Results in Clinical Nutrition Research: The Good, the Bad and the Ugly of Statistically Significant Findings

by Konstantinos Gkiouras, Maria-Eleftheria Choleva, Aikaterini Verrou, Dimitrios G. Goulis, Dimitrios P. Bogdanos and Maria G. Grammatikopoulou

Nutrients 2022, 14(23), 5164; https://doi.org/10.3390/nu14235164 - 4 Dec 2022

Cited by 2 | Viewed by 3610

Abstract

Positive (statistically significant) findings are easily produced in nutrition research when specific aspects of the research design and analysis are not accounted for. To address this issue, recently, a pledge was made to reform nutrition research and improve scientific trust on the science, [...] Read more.

Positive (statistically significant) findings are easily produced in nutrition research when specific aspects of the research design and analysis are not accounted for. To address this issue, recently, a pledge was made to reform nutrition research and improve scientific trust on the science, encompass research transparency and achieve reproducibility. The aim of the present meta-epidemiological study was to evaluate the statistical significance status of research items published in three academic journals, all with a focus on clinical nutrition science and assessing certain methodological/transparency issues. All research items were published between the years 2015 and 2019. Study design, primary and secondary findings, sample size and age group, funding sources, positivist findings, the existence of a published research protocol and the adjustment of nutrients/dietary indexes to the energy intake (EI) of participants, were extracted for each study. Out of 2127 studies in total, those with positive findings consisted of the majority, in all three journals. Most studies had a published research protocol, however, this was mainly due to the randomized controlled trials and not to the evidence-synthesis studies. No differences were found in the distribution of positive findings according to the existence/inexistence of a published research protocol. In the pooled sample of studies, positive findings differed according to study design and more significant findings were reported by researchers failing to report any funding source. The majority of items published in the three journals (65.9%) failed to account for the EI of participants. The present results indicate that there is still room for the improvement of nutrition research in terms of design, analyses and reporting. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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11 pages, 317 KiB

Open AccessArticle

Professional Male Beach Handball Players Performance Profile

by Alejandro Martínez-Rodríguez, Javier Sánchez-Sánchez, María Martínez-Olcina, Manuel Vicente-Martínez, Rodrigo Yáñez-Sepúlveda, Guillermo Cortés-Roco, Juan Antonio Vázquez-Diz and Juan Antonio Sánchez-Sáez

Nutrients 2022, 14(22), 4839; https://doi.org/10.3390/nu14224839 - 15 Nov 2022

Cited by 2 | Viewed by 2069

Abstract

Beach handball is a sport that has seen an increase in the number of players in the last decade. The aim of the study was to evaluate the basic measures of body composition, maturation, performance outcomes and the adherence to the Mediterranean diet [...] Read more.

Beach handball is a sport that has seen an increase in the number of players in the last decade. The aim of the study was to evaluate the basic measures of body composition, maturation, performance outcomes and the adherence to the Mediterranean diet of professional beach handball players, as a function of category (junior vs. senior) and playing positions. Thirty-six professional beach handball players participated in the study: 18 seniors (age: 25.0 ± 5.19) and 18 juniors (age: 16.7 ± 0.46); Each player’s body composition and different sports performance variables were analysed using the CMJ test, the Abalakov test, the Yo-Yo Test IR1 and the handgrip test. The Mediterranean diet Adherence was analysed using the KIDMED questionnaire. Significant differences are observed for all performance variables, with the values of senior players being higher in all cases (p < 0.005). Moreover, the adherence to the Mediterranean diet is moderate. Positive correlations were observed between the CMJ and weight (p = 0.012) and the CMJ and the BMI (p = 0.003). The same was observed for the Abalakov test, with p = 0.004 for weight and p = 0.001 for the BMI. Regarding the dynamometry, it positively correlates with the height (p = 0.002), the sitting height (p = 0.008), wingspan (p < 0.001) and weight (p = 0.011). The opposite occurred with the Yo-Yo Test and the KIDMED variables. Conclusions: One aspect to improve, as a key performance factor, would be the adherence to the Mediterranean diet for both categories. Players with a better adherence, achieved better results in the performance tests. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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17 pages, 1111 KiB

Open AccessArticle

The Relative Merits of Observational and Experimental Research: Four Key Principles for Optimising Observational Research Designs

by Robert Hamlin

Nutrients 2022, 14(21), 4649; https://doi.org/10.3390/nu14214649 - 3 Nov 2022

Cited by 1 | Viewed by 1728

Abstract

The main barrier to the publication of observational research is a perceived inferiority to randomised designs with regard to the reliability of their conclusions. This commentary addresses this issue and makes a set of recommendations. It analyses the issue of research reliability in [...] Read more.

The main barrier to the publication of observational research is a perceived inferiority to randomised designs with regard to the reliability of their conclusions. This commentary addresses this issue and makes a set of recommendations. It analyses the issue of research reliability in detail and fully describes the three sources of research unreliability (certainty, risk and uncertainty). Two of these (certainty and uncertainty) are not adequately addressed in most research texts. It establishes that randomised designs are vulnerable as observation studies to these two sources of unreliability, and are therefore not automatically superior to observational research in all research situations. Two key principles for reducing research unreliability are taken from R.A. Fisher’s early work on agricultural research. These principles and their application are described in detail. The principles are then developed into four key principles that observational researchers should follow when they are designing observational research exercises in nutrition. It notes that there is an optimal sample size for any particular research exercise that should not be exceeded. It concludes that best practice in observational research is to replicate this optimal sized observational exercise multiple times in order to establish reliability and credibility. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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19 pages, 3495 KiB

Open AccessArticle

Using the Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM) Approach to Assess the Strength of Evidence on Associations between Dietary Patterns and All-Cause Mortality

by Kate Wingrove, Mark A. Lawrence, Priscila Machado, Lena D. Stephens and Sarah A. McNaughton

Nutrients 2022, 14(20), 4340; https://doi.org/10.3390/nu14204340 - 17 Oct 2022

Cited by 1 | Viewed by 1769

Abstract

Dietary guidelines should be underpinned by high-quality evidence. Quality assessment methods that reflect traditional evidence hierarchies prioritise evidence from randomised controlled trials (RCTs). The Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM) approach is an alternative quality assessment method for research questions that [...] Read more.

Dietary guidelines should be underpinned by high-quality evidence. Quality assessment methods that reflect traditional evidence hierarchies prioritise evidence from randomised controlled trials (RCTs). The Hierarchies of Evidence Applied to Lifestyle Medicine (HEALM) approach is an alternative quality assessment method for research questions that for practical and/or ethical reasons, cannot be answered using RCTs. The aim of this study was to investigate how the HEALM approach could be used to assess the strength of evidence on associations between dietary patterns and all-cause mortality (a research question that is difficult to answer using RCTs). Two data sources were used: an existing systematic review of dietary patterns and all-cause mortality that synthesised evidence from observational studies; and an overview of reviews that was conducted to summarise relevant evidence from mechanistic and intervention studies. A set of four criteria were developed and used in the application of HEALM. Using different datasets in combination, the strength of evidence was rated as ‘Grade B: moderate/suggestive’ or ‘Grade C: insufficient/inconclusive’. HEALM is a novel approach for integrating and assessing the strength of evidence from mechanistic, intervention, and observational studies. Further research is needed to address the practical challenges that were identified in the application of HEALM. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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12 pages, 1300 KiB

Open AccessArticle

Change in the Healthiness of Foods Sold in an Australian Supermarket Chain Following Implementation of a Shelf Tag Intervention Based on the Health Star Rating System

by Adrian J. Cameron, Amy Brown, Liliana Orellana, Josephine Marshall, Emma Charlton, Winsfred W. Ngan, Jaithri Ananthapavan, Jasmine Isaacs, Miranda Blake and Gary Sacks

Nutrients 2022, 14(12), 2394; https://doi.org/10.3390/nu14122394 - 9 Jun 2022

Cited by 6 | Viewed by 3501

Abstract

Introduction: Most people in Australia buy most of their food in supermarkets. Marketing techniques promoting healthy foods in supermarkets can be important to encourage healthy eating at a population level. Shelf tags that highlight the healthiness of products have been identified as one [...] Read more.

Introduction: Most people in Australia buy most of their food in supermarkets. Marketing techniques promoting healthy foods in supermarkets can be important to encourage healthy eating at a population level. Shelf tags that highlight the healthiness of products have been identified as one such promising initiative. The aim of this study was to assess changes in the healthiness of foods sold in an Australian supermarket chain following implementation of a shelf tag intervention based on the Australian Health Star Rating (HSR) system. Methods: A controlled, non-randomised trial was undertaken in seven supermarkets (intervention: n = 3; control: n = 4) of a single chain in Victoria, Australia, over 12 weeks (4 weeks baseline, 8 weeks intervention period) between August and November 2015. The intervention involved provision of a shelf tag indicating the HSR of all packaged products that scored 4.5 or 5 stars (‘high-HSR products’) using the Australian HSR system. Posters indicating the healthiness of fresh fruits and vegetables (not eligible for an HSR rating, as they are not packaged) were also installed. Weekly per store sales data were provided by the retailer. In an intention-to-treat analysis (with intervention status of individual products based on their eligibility to be tagged), the proportion (%) of all ‘high-HSR’ packaged food sold and the volume of key nutrients (saturated fat, total fat, sodium, total sugar, protein, carbohydrates and energy) per 100 g sold were assessed. Difference-in-difference analyses were conducted to determine the difference between intervention and control stores in terms of mean outcomes between baseline and intervention periods. Customer exit surveys (n = 304) were conducted to evaluate awareness and use of the shelf tags and posters. Results: The proportion of ‘high-HSR products’ sold increased in the intervention period compared to the baseline period in each of the three intervention stores (average increase of 0.49%, 95% CI: −0.02, 0.99), compared to a decrease of −0.15% (−0.46, 0.15) in control stores (p = 0.034). The overall increase in intervention compared to control stores (difference-in-difference) of 0.64% represents an 8.2% increase in the sales of ‘high-HSR products’. Sales of total sugar, total fat, saturated fat, carbohydrates, sodium, protein and total energy in packaged food all decreased significantly more in intervention stores compared to control stores. Sales of fresh fruits and vegetables decreased in intervention stores compared to control stores. Customer surveys found that 34.4% noticed the shelf tags. Of those who noticed the tags, 58% believed the shelf tags influenced their purchases. Conclusions: With this study, we found that the use of shelf tags that highlight the healthiest packaged foods in a supermarket setting showed promise as a mechanism to improve the healthiness of purchases. Opportunities to scale up the intervention warrant exploration, with further research needed to assess the potential impact of the intervention on overall population diets over the longer term. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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18 pages, 658 KiB

Open AccessArticle

Cost–Benefit and Cost–Utility Analyses to Demonstrate the Potential Value-for-Money of Supermarket Shelf Tags Promoting Healthier Packaged Products in Australia

by Jaithri Ananthapavan, Gary Sacks, Liliana Orellana, Josephine Marshall, Ella Robinson, Marj Moodie, Miranda Blake, Amy Brown, Rob Carter and Adrian J. Cameron

Nutrients 2022, 14(9), 1919; https://doi.org/10.3390/nu14091919 - 3 May 2022

Cited by 4 | Viewed by 3494

Abstract

The supermarket environment impacts the healthiness of food purchased and consumed. Shelf tags that alert customers to healthier packaged products can improve the healthiness of overall purchases. This study assessed the potential value-for-money of implementing a three-year shelf tag intervention across all major [...] Read more.

The supermarket environment impacts the healthiness of food purchased and consumed. Shelf tags that alert customers to healthier packaged products can improve the healthiness of overall purchases. This study assessed the potential value-for-money of implementing a three-year shelf tag intervention across all major supermarket chains in Australia. Cost–benefit analyses (CBA) and cost–utility analyses (CUA) were conducted based on results of a 12-week non-randomised controlled trial of a shelf tag intervention in seven Australian supermarkets. The change in energy density of all packaged foods purchased during the trial was used to estimate population-level changes in mean daily energy intake. A multi-state, multiple-cohort Markov model estimated the subsequent obesity-related health and healthcare cost outcomes over the lifetime of the 2019 Australian population. The CBA and CUA took societal and healthcare sector perspectives, respectively. The intervention was estimated to produce a mean reduction in population body weight of 1.09 kg. The net present value of the intervention was approximately AUD 17 billion (B). Over 98% of the intervention costs were borne by supermarkets. CUA findings were consistent with the CBA—the intervention was dominant, producing both health benefits and cost-savings. Shelf tags are likely to offer excellent value-for-money from societal and healthcare sector perspectives. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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Review

Jump to: Research, Other

15 pages, 1609 KiB

Open AccessReview

An Overview of Methods and Exemplars of the Use of Mendelian Randomisation in Nutritional Research

by Derrick A. Bennett and Huaidong Du

Nutrients 2022, 14(16), 3408; https://doi.org/10.3390/nu14163408 - 19 Aug 2022

Cited by 6 | Viewed by 3295

Abstract

Objectives: It is crucial to elucidate the causal relevance of nutritional exposures (such as dietary patterns, food intake, macronutrients intake, circulating micronutrients), or biomarkers in non-communicable diseases (NCDs) in order to find effective strategies for NCD prevention. Classical observational studies have found evidence [...] Read more.

Objectives: It is crucial to elucidate the causal relevance of nutritional exposures (such as dietary patterns, food intake, macronutrients intake, circulating micronutrients), or biomarkers in non-communicable diseases (NCDs) in order to find effective strategies for NCD prevention. Classical observational studies have found evidence of associations between nutritional exposures and NCD development, but such studies are prone to confounding and other biases. This has direct relevance for translation research, as using unreliable evidence can lead to the failure of trials of nutritional interventions. Facilitated by the availability of large-scale genetic data, Mendelian randomization studies are increasingly used to ascertain the causal relevance of nutritional exposures and biomarkers for many NCDs. Methods: A narrative overview was conducted in order to demonstrate and describe the utility of Mendelian randomization studies, for individuals with little prior knowledge engaged in nutritional epidemiological research. Results: We provide an overview, rationale and basic description of the methods, as well as strengths and limitations of Mendelian randomization studies. We give selected examples from the contemporary nutritional literature where Mendelian randomization has provided useful evidence on the potential causal relevance of nutritional exposures. Conclusions: The selected exemplars demonstrate the importance of well-conducted Mendelian randomization studies as a robust tool to prioritize nutritional exposures for further investigation. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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Other

Jump to: Research, Review

12 pages, 2302 KiB

Open AccessEditor’s ChoiceSystematic Review

Diet and Risk of Gastric Cancer: An Umbrella Review

by Emmanouil Bouras, Konstantinos K. Tsilidis, Marianthi Triggi, Antonios Siargkas, Michail Chourdakis and Anna-Bettina Haidich

Nutrients 2022, 14(9), 1764; https://doi.org/10.3390/nu14091764 - 23 Apr 2022

Cited by 25 | Viewed by 5259

Abstract

Several dietary exposures have been associated with gastric cancer (GC), but the associations are often heterogenous and may be afflicted by inherent biases. In the context of an Umbrella Review (UR), we provide an overview and a critical evaluation of the strength and [...] Read more.

Several dietary exposures have been associated with gastric cancer (GC), but the associations are often heterogenous and may be afflicted by inherent biases. In the context of an Umbrella Review (UR), we provide an overview and a critical evaluation of the strength and quality, and evidence classification of the associations of diet-related exposures in relation to the risk of GC. We searched PubMed and Scopus for eligible meta-analyses of observational studies published in English from inception to 12 December 2021, and for any identified association, we applied robust epidemiological validity evaluation criteria and individual study quality assessment using AMSTAR. We screened 3846 titles/abstracts and assessed 501 full articles for eligibility, of which 49 were included in the analysis, investigating 147 unique exposures in relation to GC, cardia (GCC) or non-cardia (GNCC) cancer. Supported by suggestive evidence, positive associations were found comparing the highest vs. lowest categories for: heavy (>42 g/day) alcohol consumption (Relative Risk (RR) = 1.42, 95% Confidence Interval (CI): 1.20–1.67), salted fish consumption (RR = 1.56, 95% CI:1.30–1.87) and waist circumference (RR = 1.48, 95% CI:1.24–1.78) and an inverse association for the healthy lifestyle index (RR = 0.60, 95% CI:0.48–0.74) in relation to GC. Additionally, a positive association was found comparing obese individuals (Body Mass Index (BMI) ≥ 30) to normal-weight individuals (BMI: 18.5–25) (RR = 1.82, 95% CI:1.32–2.49) in relation to GCC. Most of the meta-analyses were of medium-to-high quality (median items: 7.0, interquartile range: 6–9). Maintaining a normal body weight and adopting healthy dietary choices, in particular, limiting the consumption of salt-preserved foods and alcohol, can reduce the risk of gastric cancer. Full article

(This article belongs to the Special Issue Introduction to Causal Inference Methods in Nutritional Research)

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