Exercise as a Buffer Against Stress-induced Overeating

Not Applicable

Completed

Interventions: Other: Exercise intervention
Other: Delayed exercise intervention

Brief Summary: The purpose of this study is to examine the psychological benefits of chronic exercise as well as the effects of exercise training on eating behaviors and stress-induced overeating in overweight and obese women. Participants will be randomized to an 12-week exercise condition or a delayed exercise condition. Assessments will occur at baseline, 6 weeks, and 12 weeks and will include answering surveys in real-time using smartphones, several assessments of eating behaviors and dietary intake, and questionnaire measures of factors which could mediate the relationship between exercise and eating. Participants will be compensated for completing assessments and for adherence to the exercise protocol.

Recruitment & Eligibility

Inclusion Criteria

Female
18-60 years of age
BMI 25 to <40 kg/m2
Physically inactive (<60 min/week of physical activity)
Must own a smartphone
Must be willing to receive and respond to text message prompts for 14 days at baseline, 6 and 12 weeks

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Exercise condition	Exercise intervention	Participants randomized to the exercise condition will participate in a 12-week exercise training program. The exercise intervention will consist of both supervised and unsupervised exercise sessions and progress to 200 minutes/week of moderate-intensity exercise. Exercise bouts will be spread across 4-6 days and be at least 20 minutes in duration. During supervised visits, heart rate will be monitored by a member of the research staff to ensure that exercise is within the prescribed intensity range and ratings of perceived exertion and feeling state will be assessed periodically. Unsupervised exercise will be verified using objective physical activity monitors.
Delayed exercise condition	Delayed exercise intervention	Participants randomized to the delayed exercise condition will be asked not to change their exercise or eating habits over the 12-week period and will complete the same assessment measures as the exercise condition. However, following the completion of the 12-week period, participants will be given two options: 1) receive a one-on-one session with an exercise physiologist at our center and receive a written exercise program, and at this time point all study obligations will be completed, or 2) complete the identical exercise protocol as the 'exercise' condition.

Primary Outcome Measures

Name	Time	Method
Stress-induced Overeating Measured Via Smartphone Surveys	12 weeks	Participants completed EMA surveys (5x/day for 14 days). At each prompt they were asked if an eating episode occurred. If they indicated 'yes', they were asked to check all that apply: a) I ate past the point of feeling full, b) I ate more than usual, c) I had unplanned eating (i.e., consumed food when I don't usually eat and was not making up for a missed meal, or d) None of the above. If the participant responded with a, b, or c, it was classified as an 'overeating episode'. Further, at each prompt, participants were asked to the respond to the following: 'Right now I feel stressed' (1=not at all, 7=very much so). If the stress score was \>=5 at the prompt just prior to an overeating episode, then it was considered a 'stress-induced overeating episode'.
Percentage of Overeating Episodes Characterized as 'Overeating'	12 weeks	If an eating episode occurred, participants were asked to check all that apply: a) I ate past the point of feeling full, b) I ate more than usual, c) I had unplanned eating (i.e., consumed food when I don't usually eat and was not making up for a missed meal, or d) None of the above. If response was a, b, or c, it was classified as an 'overeating episode'.

Secondary Outcome Measures

Name	Time	Method
Stress as Measured Via Questionnaire	Baseline and 12 weeks	The 10-item Perceived Stress Scale (Cohen 1988) was used to assess changes in stress by treatment arm from baseline to 12 weeks. Scores on this measure range from 0-40 with a higher score indicating greater perceived stress. Presented values are 12 week scores adjusted for baseline values.
Change in Body Weight (% Initial Weight)	baseline and 12 weeks	Percent weight change from baseline to 12 weeks