The effects of an intervention designed to increase social support for weight loss and maintenance were tested among 166 volunteers recruited through newspaper advertisements in two cities.
Participants entered either alone or with 3 other people of their choosing. They were then randomized to receive a 4-month, standard diet program or the social support weight loss intervention (standard program plus social support component).
The result was the following 4 conditions:
- Enter study alone and received standard program
- Entered study with natural support group but treated as individuals and given standard program
- Entered study alone but paired with a social support group and received social support intervention
- Entered study with natural support group and receive social support intervention
All groups met weekly for 16 weeks at their respective center. During sessions facilitated by a behavioral therapist, nutritionist or both, personalized instructions and goals were created for participants.
Social support intervention groups also participated in small team building activities such as group assignments and presentations following dietary or behavioral lectures, group exercise, or being responsible for calling a specific team member to provide support.
Participants were assessed at baseline, 4, 7, 10, and 16 months. Study variables were measured in the following ways:
- Baseline: Sallis Social Support Scales for Eating and Exercise Behavior (1987).
- Follow-up: Participants ranked team members' supportiveness using a 5 point Likert scale (1=not at all supportive, 5=very supportive) AND frequency of supportive actions (i.e. exercised together), where 1=never, 2=occasionally, 3=frequently.
Weight and height were determined using a balance beam scale and stadiometer, respectively.
Data Analysis & Findings
The researchers chose the conservative intention-to-treat approach (all participants not returning for follow up are considered to have returned to baseline weight) for data analyses. A few study findings are listed below. See the full article for all comparisons.
- There was an interaction between entry status (alone or with friends) and social support intervention (p<.002). The effect of the social support activities were strongest for those who entered study alone.
- When weight lost maintenance was treated as a dichotomous variable (gained weight vs. maintained or lost weight from month 4 to 10), the entry status (p<.04) and the social support intervention effects (p<.009) were significant.
- Entry status had a greater impact on average weight loss within the first 4 months and during the entire program than the social support intervention.
Note: Although it is not explicitly stated, it appears that pathway 2 is under investigation.