Obesity
Conditions
Keywords
Obesity, weight-loss, Physical activity
Brief summary
The primary aim of this study is to evaluate the extent to which an exercise intervention timed after diet-induced weight loss (rather than initiated at the same time) improves exercise adherence and long-term weight loss. An 18 month randomized trial will be used to compare two behavioral weight loss programs; standard behavioral therapy (Standard BT) and sequential behavioral therapy (Sequential BT). The Standard BT group will receive a traditional behavioral weight loss program where diet and exercise changes are initiated at the same time. The Sequential BT group will receive a program that focuses solely on dietary changes in the initial 6 months, and then incorporates exercise in the ensuing 6 months. Both groups will be followed for 18 months to assess long-term weight loss. The hypothesis is that delivery of diet and exercise interventions in sequence will result in improved adherence to exercise and weight loss at 18 months when compared to a traditional program in which identical diet and exercise interventions are initiated at the same time. This study could identify a strategy that could aid in the development of more effective obesity treatment programs and help more people achieve and sustain a weight loss.
Interventions
BEHAVIORALSequential BT
Both study arms (Standard BT and Sequential BT) will receive an identical 6 month group-based weight loss program, followed by an identical 6 month group-based weight maintenance program, followed by an identical 6 months of weight maintenance phone support. Both groups will also receive an identical 6 month exercise intervention. Groups will differ only in the timing of exercise initiation. Sequential BT will be asked not to begin exercise during months 0-6. They will receive a progressive exercise program and exercise behavior support during months 7-12.
BEHAVIORALStandard BT
Both study arms (Standard BT and Sequential BT) will receive an identical 6 month group-based weight loss program, followed by an identical 6 month group-based weight maintenance program, followed by an identical 6 months of weight maintenance phone support. Both groups will also receive an identical 6 month exercise intervention. Groups will differ only in the timing of exercise initiation. Standard BT will begin exercise immediately upon starting the 6 month dietary weight loss intervention. They will receive a progressive exercise program and exercise behavior support during months 0-6.
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Colorado, Denver
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18-55 * Body Mass Index 27-42 kilograms/meters squared * Sedentary: defined as regular exercise of less than 100 minutes per week at moderate intensity or greater during the previous 6 months * No self-report of acute or chronic disease (heart disease, diabetes, gastrointestinal disorders and orthopedic problems in particular) * No plans to relocate or for extended travel (more than 1 week) within the next 18 months * No current tobacco use * Capable and willing to give informed consent, understand
Exclusion criteria
, and accept the randomized group assignment * Live or work within 20 minutes of the University of Colorado Anschutz Health and Wellness Center to ensure reasonable ability to comply with requirement to attend group weight loss sessions and supervised exercise sessions. Exceptions can be made at the discretion of the Study Principal Investigator (PI) on a case by case basis for highly motivated subjects. * For Females * Not currently pregnant or lactating * Not pregnant within the past 6 months * Not planning to become pregnant in the next 18 months * Sexually active women of childbearing potential may be enrolled if they have had a tubal ligation or use a reliable means of contraception.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Body Weight | Baseline, 3, 6, 9, 12, 15, and 18 months. | Body weight will be assessed. |
| Change in Body Composition | Baseline, 6, 12, and 18 months. | Body composition will be assessed. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Diet Composition | Baseline, 6, 12, and 18 months. | Dietary energy intake (calories/day) and fat intake (grams/day) will be measured. |
| Change in Engagement in Weight Control Eating Behaviors | Baseline, 6, 12, and 18 months. | Engagement in weight control eating behaviors will be measured with a questionnaire. |
| Objectively Measured Change in Physical Activity | Baseline, 6, 12, and 18 months. | Physical activity will be measured with activity monitors. |
| Change in Exercise Program Attendance and Adherence | 18 months | Exercise program attendance and adherence will be assessed throughout the 18 month program. |
| Change in Dietary Weight Loss Program Attendance and Adherence | 18 months | Dietary weight loss program attendance and adherence will be assessed throughout the 18 month program. |
| Change in Maximal Aerobic Capacity | Baseline, 6, 12, and 18 months. | Maximal aerobic capacity will be measured. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in Dietary Self-Control | Baseline, 6, 12, and 18 months. | Dietary self-control will be assessed with a questionnaire. |
| Change in Perceived Effort for Weight Control | Baseline, 6, 12, and 18 months. | Perceived effort for weight control will be measured with a questionnaire. |
| Change in Number of Exercise Related Injuries and Adverse Events | 18 months | Exercise related injuries and adverse events will be assessed throughout the 18 month program. |
| Change in Genetic and Epigenetic markers | Baseline | Baseline genetic and epigenetic biomarkers will be analyzed to determine if they are associated with baseline measures and/or changes in post-intervention measure outcomes. |
| Change in Post intervention follow-up | 24 months | Weight, objectively measured physical activity, and outcome measures #6 and #10-18 will be assessed 6 months after completion of intervention. |
| Change in Mood | Baseline, 6, 12, and 18 months. | Mood will be assessed with a questionnaire. |
| Change in Exercise Self-Efficacy | Baseline, 6, 12, and 18 months. | Exercise self-efficacy will be assessed with a questionnaire. |
| Change in Diet Self-Efficacy | Baseline, 6, 12, and 18 months. | Diet self-efficacy will be assessed with a questionnaire. |
| Change in Beliefs About Exercise Benefits and Barriers | Baseline, 6, 12, and 18 months. | Beliefs about exercise benefits and barriers will be assessed with a questionnaire. |
| Change in Motivation to Engage in a Weight Loss Treatment Program | Baseline, 6, 12, and 18 months. | Motivation for engaging in a weight-loss treatment program will be assessed with a questionnaire. |
| Change in Motivation to Engage in Exercise | Baseline, 6, 12, and 18 months. | Motivation to engage in exercise will be assessed with a questionnaire. |
| Change in Physical Activity Enjoyment | Baseline, 6, 12, and 18 months. | Physical activity enjoyment will be assessed with a questionnaire. |
Countries
United States
Outcome results
None listed