Over the past four decades, overweight and obesity prevalence in children has increased globally.3 Once considered a problem only in high-income countries, prevalence of overweight and obesity is increasing in low- and middle-income countries, particularly in urban settings. The magnitude of these changes is such that in 1980, 8% and 16% of children from developing and developed countries, respectively, were overweight (including obese), and by 2013 these rates had increased to around 13% and 23–24%, respectively.3 At the upper end of the weight spectrum, recent estimates suggest that worldwide in 2015, 107.7 million (∼5%) children under 20 years of age were obese,4 and in 2016, 41 million (∼6%) children under five years of age were classified as being moderate-severe overweight.5
Overweight, and especially obesity, in childhood is a significant public health issue due to its impact on health and quality of life in childhood6 and its propensity to persist into adulthood.7 Aside from the impact of overweight and obesity on individuals, its global economic impact is estimated to be in the order of trillions of dollars annually.8 The health consequences of childhood overweight and obesity that may present in childhood include: delayed motor development, asthma, obstructive sleep apnoea, dysglycemia and type 2 diabetes, elevated blood pressure, dyslipidemia, chronic inflammation, muscular skeletal problems, accelerated maturation, psychological difficulties and disorders, non-alcoholic fatty liver disease, gastroenterological problems and reproductive problems.6 In adults, overweight and obesity are associated with increased risk of all-cause mortality,9,10 and the incidence of numerous co-morbidities including type 2 diabetes, various types of cancer, cardiovascular diseases, asthma, gallbladder disease, osteoarthritis and chronic backpain.11
While prevention must remain the key focus for medical and public health communities responding to child and adolescent overweight and obesity, effective strategies are required for populations already affected. The cornerstone of managing child and adolescent overweight and obesity is family-centered, multicomponent lifestyle interventions based on dietary, physical activity and behavioral modification.12,13 Lifestyle interventions can reduce body mass index (BMI), and improve other cardiometabolic outcomes including blood lipids, fasting insulin and glucose, and blood pressure in children and adults.14-19
In 2007, our original systematic review on best practice dietetic management of overweight and obese children and adolescents was published,1 and the first update was published in 2013.2 Data gathered in those reviews also formed the basis of several secondary reviews on related topics.14-15,20-22 This series of reviews has been widely cited in over 125 peer-reviewed publications. Given the prevalence of overweight and obesity in childhood remains at a historical high, and the seriousness of its consequences, a second update of our review on best practice dietetic management of overweight and obese children and adolescents is warranted. In parallel, a series of Cochrane reviews on interventions for the treatment of child and adolescent overweight and obesity management were published between 2003 and 2017; those reviews included but were not restricted to interventions that featured a dietary component.23-30 There is some overlap between our series of reviews and the Cochrane review series with regards to the reporting of adiposity outcomes. However, the novel aspect of our primary systematic review and its update1,2 is that we will examine in detail the dietary outcomes of the included dietary interventions, and also the characteristics of these interventions which are associated with improvement in adiposity and dietary outcomes.
This second update of our review on best practice dietetic management of overweight and obese children and adolescents will provide key information to inform clinical practice guideline and policy development. It will also identify gaps in the evidence base requiring further research and potential areas where innovations in dietary management are needed to improve adiposity and dietary outcomes. This protocol is based on that used for the first update of this review.31 The methods described in this protocol were guided by the Joanna Briggs Institute Reviewer's Manual32,33 and recommendations for updating systematic reviews.34
As this is an updated systematic review the inclusion criteria are based on the criteria used in our previous reviews1,2 and which are specified in our previous protocol.31
This review will include interventions targeting children or adolescents who at baseline are under 20 years of age, and who are defined as overweight or obese.
Participants will be free living outpatients or inpatients in obesity clinical units or attending community programs, camps, school or one-off programs. Interventions directed exclusively at parents of eligible participants will also be reviewed. Studies will be excluded if they focus on children or adolescents with obesity attributable to a secondary or syndromal cause with the exception of type 2 diabetes mellitus or its precursor states.
Nutrition or dietary interventions of interest will be those used for the treatment of elevated body weight. Interventions will include but not be limited to those provided by any of the following:
- A dietitian solely
- A dietitian and other health professionals
- Other professionals including obesity clinics, practice nurses, general practitioners, commercial programs, train-the-trainer, community groups, gyms, schools or via the internet, telephone or mail.
The intervention focus may be described as: lifestyle modification, including modification of dietary intake alone (inclusive of meal replacements and dietary supplements), or combined with cognitive behavioral therapy and/or physical activity and/or sedentary behavior modification and/or pharmacotherapy and/or a surgical intervention.
Childhood obesity prevention RCTs will be excluded. For the purpose of this review, obesity prevention interventions are defined as the implementation of strategies to limit excess weight gain in samples that include healthy weight children or adolescents.
Acceptable control groups will include no treatment/wait-list control, usual care, a lower dose or intensity of treatment (e.g. minimal advice, written education materials) or an alternative treatment.
Measures of outcome will include but not be limited to changes in any of the following:
- Anthropometry, including BMI, age and/or sex standardized BMI measures (e.g. BMI z-score, BMI percentile), % overweight for age, waist measurement, or skinfolds.
- Clinical indicators of weight changes (e.g. serum cholesterol, plasma insulin and glucose, or blood pressure).
- Body composition, including % body fat or % lean body mass.
- Any measure related to diet, nutrition or eating, for example, dietary intake, dietary behaviors, nutrition knowledge and attitudes, and social cognitive theory constructs that relate to eating behaviors (e.g. eating intentions, self-efficacy in making food choices).
Types of studies
Given the large volume of RCTs identified by our previous reviews,1,2 this review will only include RCTs published in the peer-reviewed literature.
The search strategy is based on the previous search strategy used in 2010,2,31 and is shown in Appendix I. The only deviation from the 2010 strategy will be that two databases searched in 2010 (shown with an asterisk) will be replaced with more relevant databases, as recommended by the Senior Research Librarian who will implement the literature search strategy. The databases that will be searched are: CINAHL, MEDLINE, PreMEDLINE, Cochrane Library (all databases), Embase, Informit Health Collection (instead of AUSTROM), ProQuest Dissertations and Theses, and Scopus (instead of Current Contents). To identify additional eligible studies, we will also examine the reference lists of the most recent Cochrane review series, published between 2015 and 2017, on interventions for treating child and adolescent overweight and obesity.25-30
All citations identified through the search strategy will be imported into Covidence.35 Initially two reviewers will use Covidence to independently screen studies for eligibility against the inclusion criteria, based on information contained in the title and abstract. Full texts of all potentially relevant articles will then be retrieved and uploaded to Covidence. Two reviewers will examine the full text articles through Covidence and will independently designate if the study meets the inclusion criteria. Conflicts in eligibility decisions will be resolved by a third reviewer.
Assessment of methodological quality
All studies that meet the inclusion criteria for this review will be independently assessed for methodological quality by two reviewers, using the JBI Critical Appraisal Checklist for RCTs.32 We will modify item 11, so that item 11a will be “Were adiposity-related outcomes measured in a reliable way?” and item 11b will be “Were dietary outcomes measured in a reliable way?”. Responses will be recorded in a Microsoft Excel spreadsheet. Any disagreements that arise between the reviewers will be resolved through discussion, or with a third reviewer. These assessments will be used to develop statements on the quality of the included studies with a clear indication of the risks of bias present.
Data will be extracted from studies included in the review using a standardized data extraction tool in the form of a Microsoft Excel spreadsheet. The tool will include all the items on the JBI Data Extraction Form for Experimental/Observational Studies32 and additional items considered pertinent to the assessment of methodological quality and data synthesis. One reviewer will extract the required data and a second reviewer will check the first reviewer's extraction for accuracy and completeness. If there is disagreement between reviewers regarding the extracted data, a third reviewer will be consulted. If additional information about an included study is required then authors of the study will be contacted.
Results of comparable RCTs will be pooled in a meta-analysis to determine the effectiveness of the intervention. Comparability of the studies will be defined by the population, interventions, comparator groups and outcome measures. Review Manager (Copenhagen: The Nordic Cochrane Centre, Cochrane) will be used to perform meta-analyes. Chi square and visual interpretation of graphs will be used to assess heterogeneity. Significant heterogeneity will be defined when the p value is less than 0.05. Odds ratio will be used to summarize effect for dichotomous data, while the weighted mean difference or standardized mean difference will be used for continuous data. Where statistical pooling is not possible, the findings will be presented in narrative form including tables and figures to aid in data presentation where appropriate. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement will be used in preparation of the final report.36 A Grading of Recommendations Assessment, Development and Evaluation (GRADE) Summary of Findings will be compiled following the guidance in the GRADE handbook.37
We thank Senior Research Librarian Debbie Booth at the University of Newcastle, Australia, for assisting with the development of the literature search strategy.
This protocol was prepared with the support of a National Health and Medical Research Council Senior Research Fellowship (CC), a Gladys M. Brawn Senior Research Fellowship (CC) and a Gladys M. Brawn Fellowship support package (KD and VS).
Appendix I: Search strategies
Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R)
ProQuest Dissertations and Theses
ti(obes*) AND ti(child* OR adolesc*) AND ti(dieti* OR intervention OR treatment OR weight control OR weight management OR weight loss OR healthy weight OR weight reduction program*). Limited to English and 2010+
Informit Health Collection
obes* AND (child* OR adolescen*) AND (dietitian* OR dietician* OR intervention OR “weight control” OR “weight management” OR “weight loss” or “healthy weight” OR family OR parent* OR school OR “weight reduction program*”)
Limited to 2010-
(TITLE (obes*) AND TITLE (child* OR adolescen*) AND TITLE (dietitian* OR dietician* OR intervention OR “weight control” OR “weight management” OR “weight loss” OR “healthy weight” OR family OR parent* OR school OR “weight reduction program*”)) AND PUBYEAR > 2009 AND (LIMIT-TO (LANGUAGE, “English”))
1. Collins CE, Warren JM, Neve M, McCoy P, Stokes B. Systematic review of interventions in the management of overweight and obese children which include a dietary component. JBI Libr Syst Rev
2007; 5 1:1–70.
2. Ho M, Jensen ME, Burrows T, Neve M, Garnett SP, Baur L, et al. Best practice dietetic management of overweight and obese children and adolescents: a 2010 update of a systematic review. JBI Database System Rev Implement Rep
2013; 11 10:190–293.
3. Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C, et al. Global, regional, and national prevalence of overweight and obesity
in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet
2014; 384 9945:766–781.
4. Afshin A, Forouzanfar MH, Reitsma MB, Sur P, Estep K, et al. GBD 2015 Obesity
Collaborators. Health effects of overweight and obesity
in 195 countries over 25 years. N Engl J Med
2017; 377 1:13–27.
6. World Health Organization (WHO). Consideration of the evidence on childhood obesity
for the Commission on Ending Childhood Obesity
: report of the ad hoc working group on science and evidence for ending childhood obesity
. WHO. Geneva, 2016. Accessed August 7, 2017. Available from: http://apps.who.int/iris/bitstream/10665/206549/1/9789241565332_eng.pdf
7. Simmonds M, Llewellyn A, Owen CG, Woolacott N. Predicting adult obesity
from childhood obesity
: a systematic review and meta-analysis. Obes Rev
2016; 17 2:95–107.
9. Aune D, Sen A, Prasad M, Norat T, Janszky I, Tonstad S, et al. BMI and all cause mortality: systematic review and non-linear dose-response meta-analysis of 230 cohort studies with 3.74 million deaths among 30.3 million participants. BMJ
10. Di Angelantonio E, Bhupathiraju ShN, Wormser D, Gao P, Kaptoge S, et al. Global BMI Mortality Collaboration. Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents. Lancet
2016; 388 10046:776–786.
11. Guh DP, Zhang W, Bansback N, Amarsi Z, Birmingham CL, Anis AH. The incidence of co-morbidities related to obesity
and overweight: a systematic review and meta-analysis. BMC Public Health
13. Styne DM, Arslanian SA, Connor EL, Farooqi IS, Murad MH, Silverstein JH, et al. Pediatric obesity
-assessment, treatment, and prevention: An Endocrine Society clinical practice guideline. J Clin Endocrinol Metab
2017; 102 3:709–757.
14. Ho M, Garnett SP, Baur L, Burrows T, Stewart L, Neve M, et al. Effectiveness of lifestyle interventions in child obesity
: systematic review with meta-analysis. Pediatrics
2012; 130 6:e1647–e1671.
15. Ho M, Garnett SP, Baur LA, Burrows T, Stewart L, Neve M, et al. Impact of dietary and exercise interventions on weight change and metabolic outcomes in obese children and adolescents: a systematic review and meta-analysis of randomized trials. JAMA Pediatr
2013; 167 8:759–768.
16. Rajjo T, Almasri J, Al Nofal A, Farah W, Alsawas M, Ahmed AT, et al. The association of weight loss and cardiometabolic outcomes in obese children: systematic review and meta-regression. J Clin Endocrinol Metab
2017; 102 3:758–762.
17. Aucott L, Gray D, Rothnie H, Thapa M, Waweru C. Effects of lifestyle interventions and long-term weight loss on lipid outcomes - a systematic review. Obes Rev
2011; 12 5:e412–e425.
18. Aucott L, Rothnie H, McIntyre L, Thapa M, Waweru C, Gray D. Long-term weight loss from lifestyle intervention benefits blood pressure?: a systematic review. Hypertension
2009; 54 4:756–762.
19. Terranova CO, Brakenridge CL, Lawler SP, Eakin EG, Reeves MM. Effectiveness of lifestyle-based weight loss interventions for adults with type 2 diabetes: a systematic review and meta-analysis. Diabetes Obes Metab
2015; 17 4:371–378.
20. Collins CE, McCoy P, Neve M, Stokes B, Warren J. Measuring effectiveness of dietetic interventions in child obesity
: A systematic review of randomized trials. Arch Pediatr Adolesc Med
2006; 160 9:906–922.
21. Collins CE, Warren JM, Neve M, McCoy P, Stokes B. Systematic review of interventions in the management of overweight and obese children which include a dietary component. Int J Evid Based Healthc
2007; 5 1:2–53.
22. Gow ML, Ho M, Burrows TL, Baur LA, Stewart L, Hutchesson MJ, et al. Impact of dietary macronutrient distribution on BMI and cardiometabolic outcomes in overweight and obese children and adolescents: a systematic review. Nutr Rev
2014; 72 7:453–470.
23. Summerbell CD, Ashton V, Campbell KJ, Edmunds L, Kelly S, Waters E. Interventions for treating obesity
in children. Cochrane Database Syst Rev
24. Oude Luttikhuis H, Baur L, Jansen H, Shrewsbury VA, O’Malley C, Stolk RP, Summerbell CD. Interventions for treating obesity
in children. Cochrane Database Syst Rev
25. Al-Khudairy L, Loveman E, Colquitt JL, Mead E, Johnson RE, Fraser H, et al. Diet, physical activity and behavioural interventions for the treatment of overweight or obese adolescents aged 12 to 17 years. Cochrane Database Syst Rev
26. Mead E, Brown T, Rees K, Azevedo LB, Whittaker V, Jones D, et al. Diet, physical activity and behavioural interventions for the treatment of overweight or obese children from the age of 6 to 11 years. Cochrane Database Syst Rev
27. Mead E, Atkinson G, Richter B, Metzendorf MI, Baur L, Finer N, et al. Drug interventions for the treatment of obesity
in children and adolescents. Cochrane Database Syst Rev
28. Colquitt JL, Loveman E, O’Malley C, Azevedo LB, Mead E, Al-Khudairy L, et al. Diet, physical activity, and behavioural interventions for the treatment of overweight or obesity
in preschool children up to the age of 6 years. Cochrane Database Syst Rev
29. Loveman E, Al-Khudairy L, Johnson RE, Robertson W, Colquitt JL, Mead EL, et al. Parent-only interventions for childhood overweight or obesity
in children aged 5 to 11 years. Cochrane Database Syst Rev
30. Ells LJ, Mead E, Atkinson G, Corpeleijn E, Roberts K, Viner R, et al. Surgery for the treatment of obesity
in children and adolescents. Cochrane Database Syst Rev
31. Collins C, Burrows T, Stewart L, Garnett S, Ho M, Baur L. Systematic review protocol best practice dietetic management of overweight and obese children and adolescents. JBI Libr Syst Rev
2010; 8 (16 Suppl):1–14.
32. The Joanna Briggs Institute. Joanna Briggs Institute Reviewers’ Manual: 2017 edition. Australia: Adelaide; 2017.
33. Tufanaru C, Munn Z, Aromataris E, Campbell J, Hopp L. Chapter 3: Systematic reviews of effectiveness. In: Aromataris E, Munn Z (Editors). Joanna Briggs Institute Reviewer's Manual. The Joanna Briggs Institute, 2017. Available from https://reviewersmanual.joannabriggs.org/
34. Garner P, Hopewell S, Chandler J, MacLehose H, Schünemann HJ, Akl EA, et al. When and how to update systematic reviews: consensus and checklist. BMJ
35. Covidence systematic review software, Veritas Health Innovation, Melbourne, Australia. Accessed August 7, 2017. Available from: www.covidence.org
37. Schünemann H, Brożek J, Guyatt G, Oxman A (editors). GRADE Handbook. Handbook for grading the quality of evidence and the strength of recommendations using the GRADE approach. Updated October 2013. Accessed December 14, 2017. Available from https://gdt.gradepro.org/app/handbook/handbook.html