CARE Trial: Comparing Different Levels of Calorie Reduction for Weight Loss
Study Details
Study Description
Brief Summary
This research study will compare two weight loss programs that provide different recommendations for how to reduce your energy (or calorie) intake to achieve weight loss in an effort to determine if fixed calorie reduction or varied calorie reduction is more effective for weight loss.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Active Comparator: Fixed Energy (or Calorie) Reduction Participants randomly assigned to this arm will be instructed to reduce their food intake by a moderate amount and stay at this level of moderate reduction until their weight loss goal is achieved. |
Behavioral: Energy Reduction
|
| Experimental: Variable Energy (or Calorie) Reduction Participants randomly assigned to this arm will be instructed to alternate between two levels of calorie reduction. One level will be a small amount of calorie reduction, while the other will be a more significant amount of calorie reduction. At the instruction of the research team, participants will periodically alternate back and forth between these two goals until their weight loss goal is achieved. |
Behavioral: Energy Reduction
|
Outcome Measures
Primary Outcome Measures
- Body weight [6, 12, and 18 months]
change in body weight (kg) from baseline to follow-up assessments
Secondary Outcome Measures
- Resting energy expenditure [6, 12, and 18 months]
An indirect calorimeter with the ventilated hood technique will be used for the 30-minute measurement (the first 10 minutes will be excluded from analysis). The respiratory quotient will be calculated as the ratio of carbon dioxide production to oxygen consumption. Resting metabolic rate will be calculated from VO2 and VCO2 measurements using the Weir equation.
- Body composition [6, 12, and 18 months]
Assessed by full body DXA scan to evaluate percentage of body fat.
- Laboratory analyses [6, 12, and 18 months]
Glucose, lipids, and insulin will be analyzed using blood samples.
- Blood pressure [6, 12, and 18 months]
After a 5 minute seated rest, three measurements using an automated blood pressure device will be taken to obtain the average systolic and diastolic blood pressures.
- Hormones - ghrelin [6, 12, and 18 months]
Total ghrelin will be assessed using blood samples.
- Hormones - leptin [6, 12, and 18 months]
Total leptin will be assessed using blood samples.
- Satiety/hunger [6, 12, and 18 months]
Visual analogue scales (VAS) will be used to measure subjective ratings of appetite. Participants will be asked to provide a rating in response to several questions (e.g., "How hungry did you feel this week? How much did you think about food this week?") using a 100-mm line ranging from "not at all" to "extremely".
- Energy intake [Daily]
Participants will be encouraged to utilize web-based and mobile apps for dietary self-monitoring. Energy intake (kcal/day) will be calculated for all daily entries that include at least two eating episodes, defined as the entry of food item(s) and corresponding caloric values. Daily self-monitoring of energy intake will occur up to 365 days between baseline and month 12 time points.
- Physical activity - objective [6, 12, and 18 months]
Will be assessed via accelerometers worn by participants for seven days. Participants will be instructed to position the accelerometer at the right hip and to wear the device throughout the day except when sleeping, bathing, or participating in swimming or other water activities. These data will be used to estimate total minutes of moderate- to vigorous-intensity PA.
- Physical activity - self-report [6, 12, and 18 months]
Self-reported PA will also be assessed with the Paffenbarger Physical Activity Questionnaire (PPAQ). Both methods of PA measurement are included, as accelerometers provide objective information about total levels of activity, while the PPAQ provides additional details about the type and schedule of activities.
- Treatment adherence [6, 12, and 18 months]
Treatment adherence will be assessed by the number of treatment sessions attended as well as the number of self-monitoring forms completed, which have both been used as indicators of adherence in our previous work
- Treatment novelty [6, 12, and 18 months]
This construct will be evaluated with a 6-item measure of treatment reinforcement that assesses the extent to which participants enjoy and become less habituated to the behavioral strategies required for weight loss.
- Treatment burden [6, 12, and 18 months]
Behavioral burden of treatment will be assessed with a modified version of the Treatment Burden Questionnaire (TBQ), which includes 15 items measuring the burden of treatment, including behaviors of self-monitoring, dietary changes, maintaining physical activity, and the impact of treatment on social relationships.
- Treatment satisfaction [6, 12, and 18 months]
Participants will complete a modified version of the Treatment Satisfaction Questionnaire for Medication (TSQM) to assess attitudes and satisfaction regarding the weight loss intervention, energy prescriptions provided, and weight loss achieved. A composite score of treatment satisfaction will be calculated based on participants' responses.
- Side effects [6, 12, and 18 months]
Symptom checklist including minor (e.g., constipation, dry mouth) and more severe events (e.g., cardiovascular events) will be administered to assess potential adverse side effects associated with both treatments.
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Age 21-75
-
Body mass index (BMI) 30-50 kg/m2
Exclusion Criteria:
-
Uncontrolled hypertension (blood pressure >160/100 mm Hg)
-
Any of the following other medical conditions: myocardial infarction or cerebrovascular accident within the last six months; unstable angina within the past six months; congestive heart failure; cancer requiring treatment in past five years (exception: non-melanoma skin cancer); serious infectious diseases (e.g., self-reported HIV); chronic hepatitis; cirrhosis; chronic malabsorption syndrome; chronic pancreatitis; chronic lung diseases or orthopedic problems that limit physical activity
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Current use of any of the following medications: antipsychotic agents, monoamine oxidase inhibitors, systemic corticosteroids, antibiotics for HIV or TB, or chemotherapeutic drugs; prescription weight loss medications (past six months)
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Unwilling or unable to do any of the following: give informed consent; read English at the 5th grade level; accept random assignment; travel to the intervention site
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Likely to relocate out of the area in the next 2 years
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Participation in another randomized research project
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Weight loss > 10 pounds in past six months
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History of bariatric surgery
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Major depressive or psychiatric disorder, or excessive alcohol intake
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Potential participants living farther than 30 miles driving distance from UAB will be excluded from the study.
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Potential participants (female) that are pregnant or plan to become pregnant in the next 18 months will be excluded from participation in the study. This is a weight loss study and weight gain/loss due to pregnancy and/or delivery would confound study results. Additionally, weight loss is not recommended for pregnant women.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Alabama at Birmingham, Medical Towers Building | Birmingham | Alabama | United States | 35205 |
Sponsors and Collaborators
- University of Alabama at Birmingham
Investigators
- Principal Investigator: Gareth R Dutton, PhD, University of Alabama at Birmingham, Department of Medicine, Division of Preventive Medicine
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- R01DK103863