Quality of development and reporting of dietetic intervention studies in primary care: a systematic review of randomised controlled trials

Effectiveness of dietetic care for cancer survivors in the primary care setting: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

Nutrition plays an important role in cancer survivorship. This systematic review and meta-analysis aim to critically assess and quantify the effectiveness of nutrition care interventions provided by dietitians to survivors who have completed treatment for cancer.

METHODS

A systematic review of randomized controlled trials (RCTs) published from January 2004 to November 2023 reporting the effectiveness of primary care dietetic interventions with adult cancer survivors was conducted. PubMed, Scopus, CINAHL, Embase, ProQuest and PsycINFO databases were searched for key terms. Meta-analyses were conducted where there were sufficient studies of the same cancer type and outcomes.

RESULTS

Twelve RCTs representing 1138 cancer survivors (519 breast cancer; 75 prostate cancer; 544 colorectal cancer) were included. Primary outcome measures included weight loss (n = 6), quality of life (n = 2), reducing lymphedema-related arm volume (n = 2), nutritional status (n = 1) and increasing fruit and vegetable intake (n = 1). Weight loss was observed in studies where this was the primary outcome. Results for quality of life varied. Meta-analyses of RCTs with breast cancer survivors showed that dietitian intervention achieved a mean of 3.7 kg greater intentional weight loss and 2.3% greater body fat decrease than control (p < 0.0001).

CONCLUSIONS

This study provides evidence for the effectiveness of primary care dietetic interventions by dietitians with cancer survivors, particularly with respect to intentional weight and fat loss in breast cancer survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Dietitians can play a key role in managing weight and improving long term health outcomes and prognosis for cancer survivors beyond the acute care setting.

Conceptualization and Assessment of 24-H Timing of Eating and Energy Intake: A Methodological Systematic Review of the Chronic Disease Literature

Timing of eating (TOE) and energy intake (TOEI) has important implications for chronic disease risk beyond diet quality. The 2020 Dietary Guidelines Advisory Committee recommended developing consistent terminology to address the lack of TOE/TOEI standardization. The primary objective of this methodological systematic review was to characterize the conceptualization and assessment of TOE/TOEI within the chronic disease literature (International Prospective Register of Systematic Reviews registration number: CRD42021236621). Literature searches in Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus, Embase, PubMed, and Scopus were limited to English language publications from 2000 to August 2022. Eligible studies reported the association between TOE/TOEI and obesity, cardiovascular disease, type 2 diabetes mellitus, cancer, or a related clinical risk factor among adults (≥19 y) in observational and intervention studies. A qualitative synthesis described and compared TOE/TOEI conceptualization, definitions, and assessment methods across studies. Of the 7579 unique publications identified, 259 studies (observational [51.4 %], intervention [47.5 %], or both [1.2 %]) were eligible for inclusion. Key findings indicated that most studies (49.6 %) were conducted in the context of obesity and body weight. TOE/TOEI variables or assigned conditions conceptualized interrelated aspects of time and eating or energy intake in varying ways. Common TOE/TOEI conceptualizations included the following: 1) timepoint (specific time to represent when intake occurs, such as time of breakfast [74.8 %]); 2) duration (length of time or interval when intake does/does not occur, such as "eating window" [56.5 %]); 3) distribution (proportion of daily intake at a given time interval, such as "percentage of energy before noon" [29.8 %]); and 4) cluster (grouping individuals based on temporal ingestive characteristics [5.0 %]). Assessment, definition, and operationalization of 24-h TOE/TOEI variables varied widely across studies. Observational studies most often used surveys or questionnaires (28.9 %), whereas interventions used virtual or in-person meetings (23.8 %) to assess TOE/TOEI adherence. Overall, the diversity of terminology and methods solidifies the need for standardization to guide future research in chrononutrition and to facilitate inter-study comparisons.

Completeness of Reporting in Diet- and Nutrition-Related Randomized Controlled Trials and Systematic Reviews With Meta-Analysis: Protocol for 2 Independent Meta-Research Studies

BACKGROUND

Journal articles describing randomized controlled trials (RCTs) and systematic reviews with meta-analysis of RCTs are not optimally reported and often miss crucial details. This poor reporting makes assessing these studies' risk of bias or reproducing their results difficult. However, the reporting quality of diet- and nutrition-related RCTs and meta-analyses has not been explored.

OBJECTIVE

We aimed to assess the reporting completeness and identify the main reporting limitations of diet- and nutrition-related RCTs and meta-analyses of RCTs, estimate the frequency of reproducible research practices among these RCTs, and estimate the frequency of distorted presentation or spin among these meta-analyses.

METHODS

Two independent meta-research studies will be conducted using articles published in PubMed-indexed journals. The first will include a sample of diet- and nutrition-related RCTs; the second will include a sample of systematic reviews with meta-analysis of diet- and nutrition-related RCTs. A validated search strategy will be used to identify RCTs of nutritional interventions and an adapted strategy to identify meta-analyses in PubMed. We will search for RCTs and meta-analyses indexed in 1 calendar year and randomly select 100 RCTs (June 2021 to June 2022) and 100 meta-analyses (July 2021 to July 2022). Two reviewers will independently screen the titles and abstracts of records yielded by the searches, then read the full texts to confirm their eligibility. The general features of these published RCTs and meta-analyses will be extracted into a research electronic data capture database (REDCap; Vanderbilt University). The completeness of reporting of each RCT will be assessed using the items in the CONSORT (Consolidated Standards of Reporting Trials), its extensions, and the TIDieR (Template for Intervention Description and Replication) statements. Information about practices that promote research transparency and reproducibility, such as the publication of protocols and statistical analysis plans will be collected. There will be an assessment of the completeness of reporting of each meta-analysis using the items in the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and collection of information about spin in the abstracts and full-texts. The results will be presented as descriptive statistics in diagrams or tables. These 2 meta-research studies are registered in the Open Science Framework.

RESULTS

The literature search for the first meta-research retrieved 20,030 records and 2182 were potentially eligible. The literature search for the second meta-research retrieved 10,918 records and 850 were potentially eligible. Among them, random samples of 100 RCTs and 100 meta-analyses were selected for data extraction. Data extraction is currently in progress, and completion is expected by the beginning of 2023.

CONCLUSIONS

Our meta-research studies will summarize the main limitation on reporting completeness of nutrition- or diet-related RCTs and meta-analyses and provide comprehensive information regarding the particularities in the reporting of intervention studies in the nutrition field.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43537.

Protocol for a meta-research study of protocols for diet or nutrition-related trials published in indexed journals: general aspects of study design, rationale and reporting limitations

INTRODUCTION

The Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) reporting guideline establishes a minimum set of items to be reported in any randomised controlled trial (RCT) protocol. The Template for Intervention Description and Replication (TIDieR) reporting guideline was developed to improve the reporting of interventions in RCT protocols and results papers. Reporting completeness in protocols of diet or nutrition-related RCTs has not been systematically investigated. We aim to identify published protocols of diet or nutrition-related RCTs, assess their reporting completeness and identify the main reporting limitations remaining in this field.

METHODS AND ANALYSIS

We will conduct a meta-research study of RCT protocols published in journals indexed in at least one of six selected databases between 2012 and 2022. We have run a search in PubMed, Embase, CINAHL, Web of Science, PsycINFO and Global Health using a search strategy designed to identify protocols of diet or nutrition-related RCTs. Two reviewers will independently screen the titles and abstracts of records yielded by the search in Rayyan. The full texts will then be read to confirm protocol eligibility. We will collect general study features (publication information, types of participants, interventions, comparators, outcomes and study design) of all eligible published protocols in this contemporary sample. We will assess reporting completeness in a randomly selected sample of them and identify their main reporting limitations. We will compare this subsample with the items in the SPIRIT and TIDieR statements. For all data collection, we will use data extraction forms in REDCap. This protocol is registered on the Open Science Framework (DOI: 10.17605/OSF.IO/YWEVS).

ETHICS AND DISSEMINATION

This study will undertake a secondary analysis of published data and does not require ethical approval. The results will be disseminated through journals and conferences targeting stakeholders involved in nutrition research.

Designing an online intervention for adults with addictive eating: a qualitative integrated knowledge translation approach

INTRODUCTION

Codesign is a meaningful end-user engagement in research design. The integrated knowledge translation (IKT) framework involves adopting a collaborative research approach to produce and apply knowledge to address real-world needs, resulting in useful and useable recommendations that will more likely be applied in policy and practice. In the field of food addiction (FA), there are limited treatment options that have been reported to show improvements in FA symptoms.

OBJECTIVES

The primary aim of this paper is to describe the step-by-step codesign and refinement of a complex intervention delivered via telehealth for adults with FA using an IKT approach. The secondary aim is to describe our intervention in detail according to the TIDieR checklist.

DESIGN

This study applies the IKT process and describes the codesign and refinement of an intervention through a series of online meetings, workshops and interviews.

PARTICIPANTS

This study included researchers, clinicians, consumers and health professionals.

PRIMARY OUTCOME MEASURE

The primary outcome was a refined intervention for use in adults with symptoms of FA for a research trial.

RESULTS

A total of six female health professionals and five consumers (n=4 female) with lived overeating experience participated in two interviews lasting 60 min each. This process resulted in the identification of eight barriers and three facilitators to providing and receiving treatment for FA, eight components needed or missing from current treatments, telehealth as a feasible delivery platform, and refinement of key elements to ensure the intervention met the needs of both health professionals and possible patients.

CONCLUSION

Using an IKT approach allowed for a range of viewpoints and enabled multiple professions and disciplines to engage in a semiformalised way to bring expertise to formulate a possible intervention for FA. Mapping the intervention plan to the TIDieR checklist for complex interventions, allowed for detailed description of the intervention and the identification of a number of areas that needed to be refined before development of the finalised intervention protocol.

Quality improvement strategies enhance primary care dietetics: A systematic review and meta-analysis

BACKGROUND

Quality improvement strategies have been widely applied in health care; however, little is known about their use in primary care dietetics. This review aims to describe and evaluate the effectiveness of quality improvement strategies that seek to improve patient outcomes by enhancing dietetic care compared to standard dietetic care.

METHODS

The study employed a systematic review and meta-analysis design following PRISMA guidelines and included studies up to March 2021. Studies were included if they used a randomised controlled trial (RCT) design to evaluate the effect of a quality improvement strategy applied to care delivered by a dietitian on patient outcomes. A meta-analysis was conducted where there were sufficient studies with homogeneous populations and outcome measures.

RESULTS

Twelve RCTs (n = 1604) met the inclusion criteria for review and five studies (n = 511) were eligible for meta-analysis for glycated haemoglobin in patients with type 2 diabetes. The most frequently reported quality improvement strategies addressed disease management programs (58%), patient education (67%), group care (42%) and patient self-management (42%). A positive intervention effect was reported in 50% of the included studies. A low grade of evidence supported a positive intervention effect for quality improvement intervention by a dietitian for glycated haemoglobin (pooled mean difference = -0.39% with 95% confidence interval = -0.70 to -0.08, p = 0.01) in n = 511 patients with type 2 diabetes mellitus.

CONCLUSIONS

Interventions aimed at enhancing quality in primary care dietetic practice support improvements in patient outcomes. Further research on quality improvement interventions for patient outcomes is required to strengthen the evidence base in this important topic.

How cost-effective is nutrition care delivered in primary healthcare settings? A systematic review of trial-based economic evaluations

CONTEXT

Nutrition care is an effective lifestyle intervention for the treatment and prevention of many noncommunicable diseases. Primary care is a high-value setting in which to provide nutrition care.

OBJECTIVE

The objective of this review was to evaluate the cost-effectiveness of nutrition care interventions provided in primary care settings.

DATA SOURCES

Medline, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Central Register of Controlled Trials, EconLit, and the National Health Service Economic Evaluation Database (NHS EED) were searched from inception to May 2021.

DATA EXTRACTION

Data extraction was guided by the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) reporting guidelines. Randomized trials of nutrition interventions in primary care settings were included in the analysis if incremental cost-effectiveness ratios were reported. The main outcome variable incremental cost-effectiveness ratios (ICERs) and reported interpretations were used to categorize interventions by the cost-effectiveness plane quadrant.

RESULTS

Of 6837 articles identified, 10 were included (representing 9 studies). Eight of the 9 included studies found nutrition care in primary care settings to be more costly and more effective than usual care . High study heterogeneity limited further conclusions.

CONCLUSION

Nutrition care in primary care settings is effective, though it requires investment; it should, therefore, be considered in primary care planning. Further studies are needed to evaluate the long-term cost-effectiveness of providing nutrition care in primary care settings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020201146.

Mapping the literature on primary care research reporting: a scoping review

BACKGROUND

Despite broad efforts to improve the reporting of biomedical research, no reporting guideline exists for primary care (PC) research. Little is known about current reporting practices or how well reports meet the needs of varied users in PC.

OBJECTIVE

To map the published literature on PC research reporting: quality, strengths and weaknesses, recommendations and efforts to improve reporting.

METHODS

Scoping review of literature across seven major databases and search engines to identify all articles on PC research reporting published in English, 2000-20. An additional secondary search of references of these 25 articles and consideration of expert panel suggestions. Structured data extraction by multiple reviewers using a predetermined form.

RESULTS

Search yielded 2847 unique titles, of which 126 underwent full-text review and 25 met inclusion criteria. Publications included opinion pieces (9), systematic reviews (5), methods articles (2), literature reviews (4), qualitative studies (4) and surveys (1). Studies focussed on a variety of topics and research methods. All publications identified the need for improved reporting and recommended items to include in reports. Most commonly, publications cited the need for more detailed reporting on the context of study interventions, clinical settings and health care systems. Most publications endorsed the use of reporting guidelines and recognized the unique needs of PC research reporting.

CONCLUSIONS

Published research and opinion identify unique needs for PC research reports and support new guidance to improve the validity, generalizability and application of study findings.

Common Limitations and Challenges of Dietary Clinical Trials for Translation into Clinical Practices

The progressive development of clinical and public health nutrition has long relied on dietary clinical trials (DCTs), investigating the causal relationship between diet and multiple risk factors of non-communicable and chronic diseases. DCTs are also hallmarks for establishing dietary requirements and promoting overall nutritional health among the population. Despite their critical importance in translation into public health strategies and practices, DCTs have several limitations and challenges for study design, implementation and finding interpretation. The complex nature of nutrition interventions, collinearity between diet components, multi-target effects of the interventions, diverse dietary behaviors, and food culture are the most challenging issues. Furthermore, baseline exposure and dietary status, appropriate control groups, blinding, randomization, and poor adherence undermine the effectiveness of DCTs in translation into practices. Disruptive factors will be minimized if researchers are committed to following good clinical practice (GCP) standards available for common designs of clinical trials. Planning DCTs, however, needs careful considerations for hypothesis generation, study design development, the definition of primary and secondary outcome measures, and target population.

i-Rebound after Stroke-Eat for Health: Mediterranean Dietary Intervention Co-Design Using an Integrated Knowledge Translation Approach and the TIDieR Checklist

Lifestyle interventions to reduce second stroke risk are complex. For effective translation into practice, interventions must be specific to end-user needs and described in detail for replication. This study used an Integrated Knowledge Translation (IKT) approach and the Template for Intervention Description and Replication (TIDieR) checklist to co-design and describe a telehealth-delivered diet program for stroke survivors. Stroke survivors and carers (n = 6), specialist dietitians (n = 6) and an IKT research team (n = 8) participated in a 4-phase co-design process. Phase 1: the IKT team developed the research questions, and identified essential program elements and workshop strategies for effective co-design. Phase 2: Participant co-design workshops used persona and journey mapping to create user profiles to identify barriers and essential program elements. Phase 3: The IKT team mapped Phase 2 data to the TIDieR checklist and developed the intervention prototype. Phase 4: Co-design workshops were conducted to refine the prototype for trial. Rigorous IKT co-design fundamentally influenced intervention development. Modifications to the protocol based on participant input included ensuring that all resources were accessible to people with aphasia, an additional support framework and resources specific to outcome of stroke. The feasibility and safety of this intervention is currently being pilot tested (randomised controlled trial; 2019/ETH11533, ACTRN12620000189921).

Reporting of Randomized Controlled Trials Investigating an Enteral or Parenteral Nutrition Intervention in Critical Illness According to the CONSORT Statement: A Systematic Review and Recommendation of Minimum Standard Reporting Criteria

Lack of reporting consistency is common in randomized controlled trials (RCTs) in critical care nutrition. This impacts synthesis and interpretation and may misinform clinical practice. The objective was to evaluate reporting of parallel-group RCTs of enteral or parenteral nutrition interventions in critically ill adults against the recommendations in the Consolidated Standards of Reporting Trials (CONSORT) 2010 guidelines and a priori-defined nutrition criteria. A systematic search of CENTRAL, MEDLINE, EMBASE, and CINAHL was conducted to identify RCTs published from January 2011 to February 14, 2020. The primary outcome was the percentage of CONSORT criteria "completely met" (a score of 1) from all included studies (out of a total possible score of 37). Secondary outcomes included the percentage of CONSORT criteria that were "partially" or "not met" and the percentage of a priori-defined nutrition criteria that were "completely," "partially," or "not met" (adjusted to reflect criteria applicable to the paper). Data are presented as mean (standard deviation). Comparisons of normally distributed continuous data were made using a t-test (P < .05). Of 18,969 articles identified, 56 studies met inclusion criteria. Of these, 60% (19%) of the eligible CONSORT criteria were "completely met," 20% (9%) "partially met," and 20% (15%) "not met." For the nutrition criteria, 41% (20%) of the eligible criteria were "completely met," 25% (14%) "partially met," and 34% (17%) "not met." Reporting against CONSORT guidelines was variable and often incomplete in relation to important a priori-defined nutrition variables.

The Use of Behavior Change Theories in Dietetics Practice in Primary Health Care: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Behavior change theories frameworks provide the theoretical underpinning for effective health care. The extent to which they are applied in contemporary dietetics interventions has not been explored.

OBJECTIVE

To systematically review the evidence of behavior change theory-based interventions delivered by credentialed nutrition and dietetics practitioners in primary health care settings.

METHODS

Medline, the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Embase, and Cochrane databases were searched for English language, randomized controlled trials before August 2019. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. Eligible interventions included adults (aged ≥18 years) receiving face-to-face dietetics care underpinned by behavior change theories in primary health care settings with outcome measures targeting changes in health behaviors or health outcomes. Screening was conducted independently in duplicate and data were extracted using predefined categories. The quality of each study was assessed using the Cochrane Risk of Bias tool. The body of evidence was assessed using the Academy of Nutrition and Dietetics Evidence Analysis Manual Conclusion Grading Table.

RESULTS

Thirty articles reporting on 19 randomized controlled trials met the eligibility criteria, representing 5,172 adults. Thirteen studies (68%) showed significant improvements for the primary outcome measured. Social cognitive theory was the behavior change theory most commonly applied in interventions (n=15) with 11 finding significant intervention effects. Goal setting, problem solving, social support, and self-monitoring were the most commonly reported techniques (n=15, n=14, n=11, and n=11, respectively). Most studies had a high (n=11) or unclear (n=8) risk of bias. There was fair evidence (Grade II) supporting the use of behavior change theories to inform development of dietetics interventions.

CONCLUSIONS

Interventions delivered by credentialed nutrition and dietetics practitioners that were underpinned by behavior change theories and utilizing various behavior change techniques were found to have potential to be more effective at improving patient health outcomes than dietary interventions without theoretical underpinnings. Findings from this review should inform future primary health care research in the area of dietary behavior change. In addition, findings from this review highlight the need for stronger documentation of use of behavior change theory and techniques that map on to the theory within dietetics practice.

Replicating group-based education interventions for the management of type 2 diabetes: a review of intervention reporting

AIMS

To assess the completeness of reporting of group-based education interventions for the management of type 2 diabetes.

METHODS

A previous systematic review of group-based education programmes for adults with type 2 diabetes identified eligible intervention studies. Data were extracted and assessed using the Template for Intervention Description and Replication ('TIDieR') checklist. Missing data were sourced from other published material, or by contacting authors.

RESULTS

Fifty-three publications describing 47 studies were included. No publications sufficiently described all items. Authors of 43 of the 47 included studies (91%) were contacted via e-mail to obtain missing data in order to complete the TIDieR checklist. Seven (16%) did not respond. Additional data were obtained for 33/47 studies (70%). Most studies (45/47, 96%) described the intervention duration and frequency, detailed the procedures and rationale (40/47, 85%), provided a brief intervention name and explained any individual tailoring (38/47, 81%), defined whether providers received training and adequately described how the programme was delivered (37/47, 79%). However, few described any modifications (28/47, 60%), whether the intervention was delivered as planned (27/47, 57%), where it was delivered (21/47, 45%), whether materials were provided (19/47, 40%), and who delivered the intervention (13/47, 28%).

CONCLUSIONS

Group-based education interventions for the management of type 2 diabetes are poorly reported. To translate effective research into practice, practitioners need sufficient detail to implement evidence-based interventions. Researcher adoption of the TIDieR checklist will assist the translation and replication of published interventions.

Limited dietary interventions in rural Australian communities: A systematic review

AIM

This review aimed to synthesise the evidence on the effectiveness of dietary interventions targeting adolescents (>13 years) and adults living in rural or remote Australia.

METHODS

Six electronic databases were searched to identify dietary interventions undertaken in rural or remote communities. Studies were included if they utilised intervention and control comparisons or pre and post assessment of diet-related outcomes. If studies included metropolitan populations, dietary outcome measures had to be provided separately for rural data.

RESULTS

In total, 14 articles from 12 unique studies met the criteria for inclusion and together provided incomplete coverage across all states of Australia, included intervention studies targeted diet to address obesity, cardiovascular disease, and high blood pressure or diabetes. No studies were focussed on reducing community malnutrition. All studies, with one exception, focussed specifically on rural adults, no interventions specifically targeted adolescents in rural areas. Only two studies documented the involvement of a dietitian in intervention development or delivery. All studies produced a significant outcome for either dietary intake, body mass index, waist circumference, or diet related biomedical risk factors for individuals located in rural or remote areas of Australia.

CONCLUSION

Dietary interventions in rural Australia are under-studied, especially among the adolescent population. This is despite the high level of preventable diet-related disease burden in rural and remote Australia. Existing evidence shows promise in improving dietary intakes, but further, large scale intervention research, with the involvement of dietitians, is urgently needed to improve the health of rural communities.

Effectiveness of dietetic consultation for lowering blood lipid levels in the management of cardiovascular disease risk: A systematic review and meta-analysis of randomised controlled trials

AIM

Evidence of the effectiveness of dietetic consultation for the management of cardiovascular disease (CVD) risk factors has not been previously synthesised. A systematic review and four meta-analyses evaluated the effectiveness of dietetic consultation for lowering blood lipid levels in high-risk individuals in primary health-care settings.

METHODS

Of the 4860 records identified, 10 eligible randomised controlled trials (RCTs, n = 1530) were evaluated for reporting blood lipid outcomes following dietetic consultation (DN)-defined as at least one exclusive individual face-to-face consultation with a dietitian and comparators (C)-defined as no nutrition intervention or usual or minimal care provided by physicians and/or nurses.

RESULTS

DN groups were effective for lowering blood lipid levels across nine studies reporting total cholesterol (TC) and LDL; and across five of six studies reporting triglycerides (TG). Between-group differences were not consistently assessed, with significance levels reported in four studies all in favour of DN, P < 0.05. Meta-analyses for TC and LDL (seven studies) confirmed DN and C groups were equally effective, P > 0.05; and for TG (six studies) DN groups were significantly more effective than C groups, P < 0.05).

CONCLUSIONS

This review provides RCT evidence that dietetic counselling is effective for lowering TG levels and at least as effective as usual and minimal care for improving cholesterol levels in high-risk individuals in primary health care. However, more adequate reporting of methods and greater consistency in timing interventions and data collection will enhance the quality of the evidence and increase confidence in the health benefits of dietetic counselling for the management of CVD risk.

How Effective Are Dietitians in Weight Management? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Effective, evidence-based strategies to prevent and treat obesity are urgently required. Dietitians have provided individualized weight management counselling for decades, yet evidence of the effectiveness of this intervention has never been synthesized. The aim of this study was to examine the effectiveness of individualized nutrition care for weight management provided by dietitians to adults in comparison to minimal or no intervention. Databases (Cochrane, CINAHL plus, MedLine ovid, ProQuest family health, PubMed, Scopus) were searched for terms analogous with patient, dietetics and consultation with no date restrictions. The search yielded 5796 unique articles, with 14 randomized controlled trials meeting inclusion criteria. The risk of bias for the included studies ranged from unclear to high. Six studies found a significant intervention effect for the dietitian consultation, and a further four found significant positive change for both the intervention and control groups. Data were synthesized through random effects meta-analysis from five studies (n = 1598) with weight loss as the outcome, and from four studies (n = 1224) with Body Mass Index (BMI) decrease as the outcome. Groups receiving the dietitian intervention lost an additional 1.03 kg (95% CI:−1.40; −0.66, p < 0.0001) of weight and 0.43 kg/m² (95% CI:−0.59, −0.26; p < 0.0001) of BMI than those receiving usual care. Heterogeneity was low for both weight loss and BMI, with the pooled means varying from 1.26 to −0.93 kg and −0.4 kg/m² for weight and BMI, respectively, with the removal of single studies. This study is the first to synthesize evidence on the effectiveness of individualized nutrition care delivered by a dietitian. Well-controlled studies that include cost-effectiveness measures are needed to strengthen the evidence base.

Environmental risk factors and nonpharmacological and nonsurgical interventions for obesity: An umbrella review of meta-analyses of cohort studies and randomized controlled trials

BACKGROUND

Multiple environmental factors have been implicated in obesity, and multiple interventions, besides drugs and surgery, have been assessed in obese patients. Results are scattered across many studies and meta-analyses, and they often mix obese and overweight individuals.

MATERIALS AND METHODS

PubMed and Cochrane Database of Systematic Reviews were searched through 21 January 2017 for meta-analyses of cohort studies assessing environmental risk factors for obesity, and randomized controlled trials investigating nonpharmacological and nonsurgical therapeutic interventions for obesity. We excluded data on overweight participants. Evidence from observational studies was graded according to criteria that included the statistical significance of the random-effects summary estimate and of the largest study in a meta-analysis, the number of obesity cases, heterogeneity between studies, 95% prediction intervals, small-study effects and excess significance. The evidence of intervention studies for obesity was assessed with the GRADE framework.

RESULTS

Fifty-four articles met eligibility criteria, including 26 meta-analyses of environmental risk factors (166 studies) and 46 meta-analyses of nondrug, nonsurgical interventions (206 trials). In adults, the only risk factor with convincing evidence was depression, and childhood obesity, adolescent obesity, childhood abuse and short sleep duration had highly suggestive evidence. Infancy weight gain during the first year of life, depression and low maternal education had convincing evidence for association with paediatric obesity. All interventions had low or very-low-quality evidence with one exception of moderate-quality evidence for one comparison (no differences in efficacy between brief lifestyle primary care interventions and other interventions for paediatric obesity). Summary effect sizes were mostly small across compared interventions (maximum 5.1 kg in adults and 1.78 kg in children) and even these estimates may be inflated.

CONCLUSIONS

Depression, obesity in earlier age groups, short sleep duration, childhood abuse and low maternal education have the strongest support among proposed risk factors for obesity. Furthermore, there is no high-quality evidence to recommend treating obesity with a specific nonpharmacological and nonsurgical intervention among many available, and whatever benefits in terms of magnitude of weight loss appear small.