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Intervention Review

Transtheoretical model for dietary and physical exercise modification in weight loss management for overweight and obese adults

  1. Nik AA Tuah1,*,
  2. Cressida Amiel2,
  3. Samrina Qureshi2,
  4. Josip Car3,
  5. Balvinder Kaur2,
  6. Azeem Majeed4

Editorial Group: Cochrane Metabolic and Endocrine Disorders Group

Published Online: 5 OCT 2011

Assessed as up-to-date: 1 JAN 2011

DOI: 10.1002/14651858.CD008066.pub2


How to Cite

Tuah NAA, Amiel C, Qureshi S, Car J, Kaur B, Majeed A. Transtheoretical model for dietary and physical exercise modification in weight loss management for overweight and obese adults. Cochrane Database of Systematic Reviews 2011, Issue 10. Art. No.: CD008066. DOI: 10.1002/14651858.CD008066.pub2.

Author Information

  1. 1

    University Brunei Darussalam, PAPRSB Institute of Health Sciences, Room 4-19, Ground floor, Gadong, Brunei Darussalam

  2. 2

    Imperial College London, Department of Primary Care and Public Health, Faculty of Medicine, London, UK

  3. 3

    Imperial College London, Global eHealth Unit, Department of Primary Care and Public Health, School of Public Health, London, UK

  4. 4

    Imperial College London, Department of Primary Care and Public Health, London, UK

*Nik AA Tuah, PAPRSB Institute of Health Sciences, Room 4-19, Ground floor, University Brunei Darussalam, Jalan Tungku Link, Gadong, BE1410, Brunei Darussalam. nik_tuah@yahoo.ca. a.tuah08@imperial.ac.uk.

Publication History

  1. Publication Status: Edited (no change to conclusions), comment added to review
  2. Published Online: 5 OCT 2011

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Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary

Background

Obesity is a global public health threat. The transtheoretical model stages of change (TTM SOC) model has long been considered a useful interventional approach in lifestyle modification programmes, but its effectiveness in producing sustainable weight loss in overweight and obese individuals has been found to vary considerably. 

Objectives

To assess the effectiveness of dietary and physical activity interventions based on the transtheoretical model, to produce sustainable weight loss in overweight and obese adults.

Search methods

Studies were obtained from searches of multiple electronic bibliographic databases. Date of last search for The Cochrane Library was issue 10, 2010, for MEDLINE Dezember 2010, for EMBASE January 2011 and for PSYCHINFO Januar 2011.

Selection criteria

Trials were included if they fulfilled the following criteria: randomised controlled clinical trials using TTM SOC as a model, theoretical framework or guideline in designing lifestyle modification strategies, mainly dietary and physical exercise versus a comparison intervention of usual care; one of the outcome measures of the study was weight loss; and participants were overweight or obese adults.

Data collection and analysis

Two researchers independently applied the inclusion criteria to the identified studies and assessed risk of bias. Disagreement was resolved by discussion or by intervention of a third party. Descriptive analysis was conducted for the review.

Main results

A total of five studies met the inclusion criteria and a total of 3910 participants were evaluated. The total number of participants randomised to intervention groups was 1834 and 2076 were randomised to control groups. Overall risk of bias was high. The trials varied in length of intervention from six weeks to 24 months, with a  median length of nine months. The intervention was found to have limited impact on weight loss (about 2 kg or less). There was no conclusive evidence for sustainable weight loss. However, TTM SOC and a combination of physical activity, diet and other interventions tended to produce significant outcomes (particularly change in physical activity and dietary intake). TTM SOC was used inconsistently as a theoretical framework for intervention in the trials. Death and weight gain are the two adverse events reported by the included trials. None of the trials reported health-related quality of life, morbidity, and costs as outcomes.

Authors' conclusions

TTM SOC and a combination of physical activity, diet and other interventions resulted in minimal weight loss, and there was no conclusive evidence for sustainable weight loss. The impact of TTM SOC as theoretical framework in weight loss management may depend on how it is used as a framework for intervention and in combination with other strategies like diet and physical activities.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary

Transtheoretical model for dietary and physical exercise modification in weight loss management for overweight and obese adults

Obesity (body mass index of more than 30 kg/m2) and overweight (body mass index of 25 to less than 30 kg/m2) are increasingly important public health issues, and contribute to serious health problems and extensive economic costs worldwide. Body mass index is a common measure used in classifying overweight and obesity in adult populations and individuals, and is conforming to the World Health Organization (WHO) standard. It is defined as the weight in kilograms divided by the square of the height in meters.

Generally, weight loss programmes tend to involve diet and physical activity interventions. The 'Stages of Change' (SOC) model can be used as a framework to plan these interventions in both hospital and community settings. SOC describes the five stages an individual goes through when changing from an unhealthy behaviour to a healthy one. SOC is fundamental to what is known as the 'Transtheoretical Model' (TTM), whereby an individual's readiness to change is assessed. In this review, we assessed the use of the TTM SOC in weight management programmes for overweight and obese adults, in terms of the effects on weight loss and dietary and physical exercise behaviour change.

Five trials were included in the review and 3910 participants were evaluated, with 1834 participants randomly allocated to intervention groups and 2076 to control groups. The trials varied in length of intervention (from 6 weeks to 24 months), with a median length of nine months. The use of TTM SOC resulted in minimal weight loss (about 2 kg or less) and there was no conclusive evidence for sustainable weight loss amongst participants. However, other significant positive outcomes were noted, such as a change in physical activities behaviour and dietary intake. Weight gain was among the adverse events reported.The trials did not report other important outcomes such as health-related quality of life, morbidity and cost. The impact of TTM SOC in weight loss management may depend on how it is used in combination with other strategies and thus further rigorous research is required into this potentially valuable interventional strategy.