Obesity
Conditions
Keywords
obesity, intervention studies, patient adherence
Brief summary
Obesity is the second leading cause of preventable deaths in the United States and is associated with a wide range of diseases. In people who are obese, weight loss improves blood pressure, dyslipidemia, glycemia, and arthritis symptoms; reduces medication use for several disease processes; increases physical functioning; and enhances health-related quality of life. The current study evaluated a theoretically informed maintenance intervention. If effective, this intervention could reduce the need for future clinic visits to treat obesity and its many associated illnesses.
Detailed description
Obesity is the second leading cause of preventable deaths in the United States and is associated with a wide range of diseases. In people who are obese, weight loss improves blood pressure, dyslipidemia, glycemia, and arthritis symptoms; reduces medication use for several disease processes; increases physical functioning; and enhances health-related quality of life. Despite these benefits, most patients who achieve weight loss regain much of this weight within a year, and few effective behavioral weight maintenance interventions have been identified. Thus, there is a dire need for effective interventions that can promote weight loss maintenance. Theoretical and empirical studies indicate that behavior maintenance is a distinct state that involves different psychological processes and behavioral skills than initial behavior change. The few trials that have tested weight loss maintenance interventions have not taken this distinction into account, which may partially explain their modest findings. The current study evaluated the efficacy of a theoretically informed maintenance intervention compared to usual care. If efficacious, this intervention could reduce the need for future clinic visits to treat obesity and its many associated illnesses and could serve as a model for redesigning the MOVE! program. This 3.5-year study involved a two-arm, randomized, controlled trial. During the run-in phase, Veterans with BMI 30 kg/m2 participated in a 4-month, intensive, group-based weight loss program. Participants who lost at least 4 kg by the end of 4 months (n=222) were randomized to receive (a) usual care (n=112) for 56 weeks or (b) a theoretically-informed maintenance intervention (n=110) for 42 weeks months, followed by 14 weeks of no intervention contact to examine sustainability. The maintenance intervention involved in-person group visits that transition to individualized telephone calls, and the frequency of contact with the interventionist gradually tapered over time. Outcomes were assessed at randomization and at weeks 14, 26, 42, and 56 post-randomization. The hypotheses are that the maintenance intervention will result in at least 3.5 kg greater weight loss and greater improvements in caloric intake and physical activity over the study period, and that it will be cost-effective, compared to usual care.
Interventions
BEHAVIORALMaintenance intervention
Theoretically-informed maintenance intervention that involves in-person group visits that transition to individualized telephone calls, and the frequency of contact gradually decreases over time.
Sponsors
VA Office of Research and Development
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 74 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI \>= 30 kg/m2 * Desire to lose weight * Agrees to attend regular visits per study protocol * Has a provider at the Durham Veterans Affairs Medical Center
Exclusion criteria
* Age \>= 75 years old, * Most recent serum creatinine \>2.0 mg/dL in men, \>1.7 mg/dL in women), * Liver disease (cirrhosis, jaundice, or other stigmata of advanced liver disease), * Type 1 diabetes, * Hemoglobin A1c \>= 12% in past 6 months * unstable angina or coronary ischemia workup in past 3 months * Female: pregnancy, breastfeeding, or lack of birth control if premenopausal * Transplant recipient * Pacemaker or defibrillator (bioelectric impedance assessment might interfere with these) * Average systolic blood pressure in the past year \>= 160 mmHg AND most recent BP \>=160 mmHg * Dementia, severe psychiatric illness (e.g., major depression), alcohol problem, or illicit substance abuse * Weight loss of at least 10 lb in previous 3 months * Enrollment in a weight loss program * Unable to stand for study measurements * history of weight loss surgery * cancer not in remission * current use of appetite suppressants or weight loss medication * lack of reliable transportation or telephone
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Weight | 56 weeks post-randomization |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Estimated Daily Caloric Intake | 56 weeks | Based on self-report using Block Brief Food Frequency Questionnaire |
| Estimated Metabolic Minutes of Walking Per Week | 56 weeks | self-reported based on short form of International Physical Activity Questionnaire |
| Estimated Metabolic Minutes of Moderate Physical Activity Per Week | 56 weeks | self-reported based on short form of International Physical Activity Questionnaire |
Countries
United States
Participant flow
Recruitment details
573 people were consented. Of those, 69 did not return to provide a weight at study entry. Of the 504 who provided a weight at study entry, 200 dropped out, 82 lost \< 4 kg, and 222 lost at least 4 kg and thus were eligible for randomization in the maintenance phase.
Participants by arm
| Arm | Count |
|---|---|
| Maintenance Intervention Participants are randomized to a theoretically-informed maintenance intervention for 42 weeks, followed by 14 weeks of no intervention contact to examine sustainability. The maintenance intervention will involve in-person group visits that transition to individualized telephone calls, and the frequency of contact with the interventionist will gradually taper over time.
Interventions: Theoretically-informed maintenance intervention that involves in-person group visits that transition to individualized telephone calls, and the frequency of contact with the interventionist will gradually taper over time. | 110 |
| Usual Care Participants are randomized to receive usual care for 56 weeks | 112 |
| Total | 222 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Death | 0 | 1 |
| Overall Study | Lost to Follow-up | 16 | 6 |
| Overall Study | Withdrawal by Subject | 6 | 4 |
Baseline characteristics
| Characteristic | Usual Care | Total | Maintenance Intervention |
|---|---|---|---|
| Age, Continuous | 62.0 years STANDARD_DEVIATION 8.3 | 61.8 years STANDARD_DEVIATION 8.3 | 61.5 years STANDARD_DEVIATION 8.3 |
| Body mass index | 34.6 kilograms per meter squared STANDARD_DEVIATION 6.4 | 34.0 kilograms per meter squared STANDARD_DEVIATION 6.1 | 33.3 kilograms per meter squared STANDARD_DEVIATION 5.7 |
| Current tobacco user missing | 1 participants | 1 participants | 0 participants |
| Current tobacco user no | 102 participants | 207 participants | 105 participants |
| Current tobacco user yes | 9 participants | 14 participants | 5 participants |
| Education high school graduate | 111 participants | 217 participants | 106 participants |
| Education missing | 0 participants | 1 participants | 1 participants |
| Education not high school graduate | 1 participants | 4 participants | 3 participants |
| Employment status missing | 1 participants | 2 participants | 1 participants |
| Employment status other/disabled | 18 participants | 35 participants | 17 participants |
| Employment status retired | 65 participants | 124 participants | 59 participants |
| Employment status working full time or part-time | 28 participants | 61 participants | 33 participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 2 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 111 Participants | 216 Participants | 105 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 4 Participants | 4 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 45 Participants | 83 Participants | 38 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 4 Participants | 3 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 3 Participants | 5 Participants | 2 Participants |
| Race (NIH/OMB) White | 62 Participants | 129 Participants | 67 Participants |
| Region of Enrollment United States | 112 participants | 222 participants | 110 participants |
| Sex: Female, Male Female | 17 Participants | 34 Participants | 17 Participants |
| Sex: Female, Male Male | 95 Participants | 188 Participants | 93 Participants |
| Weight | 105.0 kilograms STANDARD_DEVIATION 21 | 103.6 kilograms STANDARD_DEVIATION 20.4 | 102.1 kilograms STANDARD_DEVIATION 19.8 |
| Weight loss during initiation phase | 7.2 kilograms STANDARD_DEVIATION 3.4 | 7.2 kilograms STANDARD_DEVIATION 3.1 | 7.2 kilograms STANDARD_DEVIATION 2.8 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 110 | 0 / 112 |
| serious Total, serious adverse events | 4 / 110 | 1 / 112 |
Outcome results
Primary
Weight
Time frame: 56 weeks post-randomization
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Maintenance Intervention | Weight | 99.2 kilograms | Standard Deviation 17.7 |
| Usual Care | Weight | 105.7 kilograms | Standard Deviation 20.1 |
Comparison: The sample size estimate was based on the primary hypothesis that patients randomized to receive the maintenance intervention would have less mean weight regain at week 56 than those randomized to usual care. The week 0 standard deviation was estimated as 24.6kg, the correlation between week 0 and week 56 as 0.95, and the week 56 dropout rate as 10%. To detect a difference of 3.5 kg with 90% power and a type I error rate of 5%, 230 total (115 in each group) randomized patients were needed.p-value: 0.0495% CI: [0.07, 3.13]Mixed Models Analysis
Secondary
Estimated Daily Caloric Intake
Based on self-report using Block Brief Food Frequency Questionnaire
Time frame: 56 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Maintenance Intervention | Estimated Daily Caloric Intake | 1207.5 kcal per day | Standard Deviation 548.3 |
| Usual Care | Estimated Daily Caloric Intake | 1339.1 kcal per day | Standard Deviation 750.5 |
Comparison: The hypothesis was that patients randomized to receive the maintenance intervention would have less caloric intake at week 56 than those randomized to usual care.p-value: 0.1195% CI: [-280.71, 29.72]Mixed Models Analysis
Secondary
Estimated Metabolic Minutes of Moderate Physical Activity Per Week
self-reported based on short form of International Physical Activity Questionnaire
Time frame: 56 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Maintenance Intervention | Estimated Metabolic Minutes of Moderate Physical Activity Per Week | 783.40 metabolic minutes per week | Standard Deviation 1175.57 |
| Usual Care | Estimated Metabolic Minutes of Moderate Physical Activity Per Week | 810.25 metabolic minutes per week | Standard Deviation 1215.14 |
Comparison: The hypothesis was that patients randomized to receive the maintenance intervention would have higher rates of moderate physical activity per week at week 56 than those randomized to usual care.p-value: 0.8395% CI: [0.57, 2.03]Mixed Models Analysis
Secondary
Estimated Metabolic Minutes of Walking Per Week
self-reported based on short form of International Physical Activity Questionnaire
Time frame: 56 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Maintenance Intervention | Estimated Metabolic Minutes of Walking Per Week | 680.72 metabolic minutes per week | Standard Deviation 721.23 |
| Usual Care | Estimated Metabolic Minutes of Walking Per Week | 665.43 metabolic minutes per week | Standard Deviation 822.3 |
Comparison: The hypothesis was that patients randomized to receive the maintenance intervention would have higher rates of walking per week at week 56 than those randomized to usual care.p-value: 0.9195% CI: [0.63, 1.68]Mixed Models Analysis