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Systematic review

Effect of interventions for weight maintenance after an intervention for reduction of overweight among children and adolescents: a systematic review

The Norwegian Institute of Public Health, Division of Health Services received in May 2019 a commission from the Directorate of Health for a systematic review on weight maintenance among children and adolescents after participating in an intervention for reduction of overweight.

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The Norwegian Institute of Public Health, Division of Health Services received in May 2019 a commission from the Directorate of Health for a systematic review on weight maintenance among children and adolescents after participating in an intervention for reduction of overweight.


Key message

The Norwegian Institute of Public Health, Division of Health Services received in May 2019 a commission from the Directorate of Health for a systematic review on weight maintenance among children and adolescents after participating in an intervention for reduction of overweight. There are available and effective interventions to reduce overweight in children, however, it is well documented that many will gain weight again after the intervention has been terminated. Our aim was to summarize relevant studies where children participated in an intervention to maintain weight after having participated in an intervention to reduce overweight.

We identified five studies comprising 910 children and adolescents. The interventions were very different and varied from a monthly newsletter to extensive workshops with a pediatrician, psychologist, dietitian and physiotherapist.

We assess all the included studies to have a high risk of bias. It is unclear if the various interventions for weight maintenance affect if the children maintain the reduced overweight (very low confidence in the results).

The interventions include many different components and it is difficult to identify if any one component is more (or less) important than others to achieve an effect. It is also unclear if the complex interventions are described well enough to be repeated.

We cannot draw any conclusions about the effect of these interventions.

Summary

Background

The Norwegian Institute of Public Health, Division of Health Services received in May 2019 a commission from the Directorate of Health for a systematic review on weight maintenance among children and adolescents that had participated in an intervention for reduction of overweight.

Between 13 and 17% of children and adolescents in Norway have overweight or obesity. The World Health Organization claim overweight and obesity to be one of the most serious health threats of our time, because overweight has serious implications on chronic diseases such as cardiovascular diseases, diabetes and musculoskeletal diseases. Treatment of children and adolescents that already have developed obesity is necessary to stop development of disease. There are effective interventions available. However, it is well documented that many people regain weight after terminating the treatment. In this systematic review, we identified and summarized effect of interventions to stabilize the weight of children and adolescents under the age of 18 years, who had already participated in treatment for reduction of overweight.   

Method

We planned to conduct a review of systematic reviews if there were any reviews available, on interventions for weight maintenance after initial treatment of overweight or obesity among children and adolescents.  As there was no systematic review of high methodological quality, we searched for primary studies and summarized those in a systematic review.

 

Criteria of inclusion

Population:                       
Children and adolescents under 18 years of age with overweight or obesity before a recently terminated treatment/intervention for reduction of overweight.

Treatment:                        
Programs/interventions designed to maintain new body mass index (BMI) after an intervention for reduction of overweight where the children have participated in and terminated before the intervention for maintenance. The intervention for maintenance has to last at least six months, and have a main purpose to maintain BMI. The duration of the intervention for reduction of overweight was not specified.

Comparison:                    
None or another intervention of weight maintenance

Primary outcomes:       
BMI, iso-BMI, BMI z- score

Language:                          
No limitations

Period of publication:  
Systematic reviews of high methodological quality published 2014 or later; for primary studies, no limitation

Study design:                   
Systematic reviews of high methodological quality
RCTs, non-randomized controlled studies and observation studies with a control group

Setting:                              
Primary or secondary care

Search strategy

Our librarian developed, with input from the review team, a search strategy for each electronic database. The search strategies were peer reviewed by another librarian.

The search for systematic reviews were conducted in June 2019, the search for primary studies were conducted in September 2019. Searches were conducted in the following databases: Cochrane Database of Systematic Reviews, Epistemonikos, CENTRAL, MEDLINE (Ovid), Embase (Ovid), PsycINFO (Ovid), and CINAHL.

Study selection, risk of bias and analysis

Two persons independently of each other assessed title and abstract identified in the systematic literature search against the inclusion criteria. Those references that were considered potentially relevant were ordered and assessed in full text by two independent persons against the same inclusion criteria. Two persons independent of each other assessed the risk of bias of the included studies using standard checklists. One person extracted information from the publications, another person double-checked if the relevant information was extracted correctly.

None of the identified interventions was studied in more than one trial, so meta-analysis was not relevant.

We assessed our confidence in the effect estimates using the Grading of Recommendations Assessment and Evaluation (GRADE) approach. We used Guideline Development Tool (GDT).

Results

Our search for systematic reviews resulted in one potential review. This review was of moderate methodological quality. If it had been of high quality, we would have considered updating it.

Our search for primary studies identified five studies with complex and different interventions. Even though all comprise children and adolescents, there are studies that only comprises children and some that only comprises adolescents. Which is reflected in if parents are a part of the intervention or not.  

The interventions on weight maintenance were very different. Three of the studies compared the following weight maintenance interventions with no intervention:

  • Short messages on the phone for nine months
  • Phone messages and a pedometer (aim for 10 000 steps/day) for ten months
  • Up to 13 consultations with the family doctor who was specially trained to do this, for twelve months.

Two studies compared the following weight maintenance interventions with another weight maintenance intervention:

  • Education and telephone conversations about behavior over an eight month period compared with monthly newsletter
  • One-hour sessions with a nutritionist every third month and a telephone conversation with a therapist every other week for 22 months compared with one-hour session with a dietitian without the telephone conversations.

Discussion

None of the studies were comparable as to the age of the participants (varies from 7-12 years to 13-16 years), interventions and participation of the parents. The weight maintaining interventions ranged from sending eight monthly newsletters, to an extensive intervention lasting 22 months where there were meetings with dietitian every third month and biweekly telephone conversation with a therapist. The interventions for reducing overweight varied from 8 weeks with physical activity to twelve months with meetings with a pediatrician, physiotherapist, psychologist, and dietitian.

The included studies assessed the effect of complex intervention. The description of the interventions were rarely presented in enough detail that it would be possible to repeat them. We cannot conclude from the studied intervention which components that has an effect (or not), and therefore we do not present detailed results in this summary.

We have performed systematic searches for literature in seven electronic databases. There might be other databases that possibly include other relevant studies. We cannot rule out the possibility that we can have missed studies in the databases where the searches were done, e.g. because the concepts of the intervention can vary when the study is comprised of multiple complex interventions that are performed one after the other. The strength of our review is our systematic approach and a reduced risk of errors because two persons worked independently in assessing titles, abstracts and the full text articles.

Conclusion

The five studies that have studied the effect of interventions to maintain weight are relatively small studies. All studies have methodological limitations and they have studied very different interventions. It is unclear if the various interventions for maintaining weight affect if children or adolescents keep the reduced overweight (very low confidence in the results). We cannon draw conclusions about the effect of these interventions.

Downloadable as PDF. In Norwegian. English summary.

About this publication

  • Year: 2020
  • By: Norwegian Institute of Public Health
  • Authors Holte HH, Dahm KT, Denison E, Hval G, Vist GE.
  • ISBN (digital): 978-82-8406-067-5