A randomized trial testing a contingency-based weight loss intervention involving social reinforcement

Area of Science:

• Behavioral Science
• Obesity Research
• Clinical Psychology

Background:

• Group-based behavioral weight loss interventions are common.
• Social reinforcement potential within weight loss groups is largely untapped.
• A social contingency (SC) paradigm has not been previously tested for weight loss.

Purpose of the Study:

• To test a weight loss intervention where group participation is contingent on meeting weight goals.
• To determine if a social contingency (SC) paradigm improves weight loss outcomes.
• To investigate the effectiveness of making group access dependent on weight loss.

Main Methods:

• Randomized controlled trial with 62 participants (84% female, 94% white, age 51.9±9.0, BMI 34.7±4.5).
• Comparison of standard behavioral weight loss (SBWL) versus a SC paradigm for 6 months.
• SC participants not meeting goals received individual treatment and rejoined groups upon goal achievement.

Main Results:

• No significant difference in overall weight loss between SC and SBWL groups (SC: -10.0±4.9 kg, SBWL: -10.8±6.4 kg).
• No significant difference in weight loss for subgroups not meeting periodic goals (SC: -7.3±4.1 kg vs. SBWL: -7.1±3.5 kg).
• Surprisingly, successful SC participants lost less weight than successful SBWL participants (P=0.02).

Conclusions:

• The tested social contingency (SC) intervention did not improve overall weight loss outcomes.
• Individual treatment offered to SC participants who missed goals may have diluted the contingency effect.
• Further research is needed to explore contingency-based approaches for weight management effectively.