The Efficacy of Group and Individual Lifestyle Interventions for Overweight and Obese Adults
: a Systematic Review and Meta-Analysis of Randomised Controlled Trials

  • Sally Abbott

    Student thesis: Master's ThesisMaster of Science by Research


    Introduction Multi-component lifestyle interventions are recommended for the weight management of adults who are overweight or obese. It is not clear, however, whether delivery individually or in groups influences the efficacy. The objective of this research was to systematically review the effectiveness of group compared to individual lifestyle interventions for weight management. Methods The databases MEDLINE, EMBASE, CINAHL, CENTRAL and ISRCTN were searched for published and on-going randomised controlled trials (RCTs) from inception to February 2017. The reference lists of included studies were also searched. Eligible studies were RCTs comparing group against individual lifestyle interventions for weight loss among adults with a BMI >25kg/m2. Risk of bias was evaluated using the Cochrane Risk of Bias tool. Heterogeneity was investigated using I2 statistics and sub-group analysis. Meta-analysis primarily used fixed effects methods and either estimated risk ratios or continuous inverse-variance methods. Results Eight RCTs with 2,139 participants were identified. Group interventions were 62% more likely to achieve a 5% weight loss relative to individual interventions (RR 1.62, 95% CI [1.40, 1.86], p= <0.00001). Heterogeneity existed (I2 35%, p= 0.15) and was explained through sub-group analysis by provider (commercial or non-commercial) (p= 0.004). Relative to individual interventions, commercial groups were 89% more likely (RR 1.89, 95% CI [1.58, 2.26], p= <0.00001) while results were similar with no significant difference for non-commercial groups(RR 1.21, 95% CI [0.95, 1.54], p= 0.11), in achieving a 5% weight loss. Commercial groups were marginally more cost-effective (£8,128 per QALY) than non-commercial groups (£8,439 per QALY). Neither group nor individual interventions were favoured when measuring efficacy by markers of cardiovascular (lipid profile, blood pressure) and diabetes (fasting glucose, fasting insulin, HbA1c) disease risk. Conclusion There is a moderate degree of certainty that neither non-commercial groups or individual interventions are favoured regarding the likelihood of achieving a 5% weight loss at 1-year. There is a high degree of certainty that commercial group participants are more likely to attain a 5% weight loss at 1-year, compared to individual intervention participants. Both commercial and non-commercial group interventions are cost-effective. Referral to a commercial group intervention should be prioritised over a non-commercial group or individual intervention; if the option is available.
    Date of Award2018
    Original languageEnglish
    Awarding Institution
    • Coventry University
    SupervisorDeborah Lycett (Supervisor)

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