Research

Adherence

Conventional Diet (CD) combined with group therapy yields better long-term success rates (median 27%) than CD alone or CD with behavior modification.

If you prefer a Conventional Diet (800-1800 kcal/day), joining a group therapy program significantly improves your chances of long-term success (median 27%) compared to dieting alone or using behavior modification alone. The social support of a group appears to be a key factor for maintaining weight loss with this diet type.

ModerateQualifiesMEDIUM confidence
Conventional diet seemed to be most efficacious in addition with group therapy... Diet combined with group therapy lead to better long-term success rates (median 27%) than did diet alone (median 15%) or diet combined with behaviour modification (median 14%).
C. Ayyad et al. · Obesity Reviews · 2000

Why this rating

Based on aggregate data from multiple study groups; supported by some controlled trials but with conflicting results regarding group therapy vs individual therapy.

Source

Long‐term efficacy of dietary treatment of obesity: a systematic review of studies published between 1931 and 1999

C. Ayyad et al. · Obesity Reviews · 2000

DOI 10.1046/j.1467-789x.2000.00019.x

systematic_review · n=3030Cited 356×
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DOI resolved against Crossref · corpus check 2026-06-10

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