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ObesityNCT01985568

Optimal Timing of Exercise Initiation Within a Lifestyle Weight Loss Program

A study testing Sequential BT and Standard BT in people with Obesity, run by University of Colorado, Denver at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 to 55 yearsHealthy volunteers can take part
Conditions the study is for
Obesity
What is being tested?
Sequential BT and Standard BT
Could I receive a placebo?
No, everyone receives an active treatment
How many people
170 participants
Where
1 siteUnited States
Study dates
Nov 2013to Sep 2018
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 55 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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
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  • 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.

Who cannot join

  • Presence or history of health problems which would affect appetite, food intake, energy metabolism, or ability to optimally participate in the exercise component including: diabetes, cardiovascular disease, peripheral vascular disease, cerebrovascular disease, uncontrolled hypertension, uncontrolled hyper or hypothyroidism, cancer (within the last 5 years, except skin cancer), human immunodeficiency virus (HIV) infection, significant gastrointestinal, pulmonary, renal, musculoskeletal, neurologic, or hematologic disease
  • Symptoms suggestive of cardiovascular disease: chest pain, shortness of breath at rest or with mild exertion, syncope
  • Abnormal resting electrocardiogram (ECG): serious arrhythmias, including multifocal Premature Ventricular Contractions (PVCs), frequent PVC's (defined as 10 or more per minute), ventricular tachycardia (defined as runs of 3 or more successive PVC's), or sustained atrial tachyarrhythmia; 2nd or 3rd degree A-V block, corrected QT interval > 480 millisecond or other significant conduction defects
  • Triglycerides > 400 milligram/deciliter (md/dL) or Low-Density Lipoprotein (LDL) cholesterol > 190 mg/dL
  • Use of prescription or over-the-counter medications known to affect appetite, weight, heart rate response to exercise, or energy metabolism
  • Use of systemic steroids (other than Oral Contraceptive Pills)
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  • Use of obesity pharmacotherapeutic agents within the last 6 months
  • History of surgical procedure for weight loss
  • History of major surgery within the past 3 months
  • Current alcohol or substance abuse
  • History of clinically diagnosed eating disorders including anorexia nervosa or bulimia
  • Current severe depression or history of severe depression within the previous year
  • History of other significant psychiatric illness (e.g. psychosis, schizophrenia, mania, bipolar disorder) which in the opinion of the Study MD would interfere with ability to adhere to dietary or exercise interventions
  • Currently participating in or planning to participate in any formal weight loss or physical activity programs or clinical trials
  • Weight loss or gain of > 5% in past 6 months for any reason except post-partum weight loss
  • Participation in a weight loss program using the Colorado Weigh curriculum within the past 3 years (exceptions can be made at the discretion of the study PI on a case-by-case basis).

Trial locations and contacts

1 site in 1 country.

United States1 site
  • University of Colorado, Anschutz Health and Wellness Center

    Aurora, Colorado, 80045

Other trials in United States

About this study

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.

Conditions
Obesity
Being tested
Sequential BT, Standard BT
Keywords
Obesity, weight-loss, Physical activity
Medical subject headings
Obesity, Weight Loss, Motor Activity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Sequential BTBehavioural

    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.

  • Standard BTBehavioural

    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.

Study groups in NCT01985568
Study groupRoleWhat they receive
Standard Behavioral Therapy (Standard BT)Active comparatorStandard BT: This group will follow a traditional model of initiating exercise concurrently with a dietary intervention for weight loss within an 18 month behavioral weight loss program.
Receives: Behavioral: Standard BT
Sequential Behavioral Therapy (Sequential BT)ExperimentalSequential BT: This group will receive diet and exercise interventions delivered sequentially within an 18 month behavioral weight loss program.
Receives: Behavioral: Sequential BT

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Body Weight

    Body weight will be assessed.

    Measured: Baseline, 3, 6, 9, 12, 15, and 18 months.

  2. Change in Body Composition

    Body composition will be assessed.

    Measured: Baseline, 6, 12, and 18 months.

Secondary outcomes (6)
  1. Objectively Measured Change in Physical Activity

    Physical activity will be measured with activity monitors.

    Measured: Baseline, 6, 12, and 18 months.

  2. Change in Maximal Aerobic Capacity

    Maximal aerobic capacity will be measured.

    Measured: Baseline, 6, 12, and 18 months.

  3. Change in Diet Composition

    Dietary energy intake (calories/day) and fat intake (grams/day) will be measured.

    Measured: Baseline, 6, 12, and 18 months.

  4. Change in Engagement in Weight Control Eating Behaviors

    Engagement in weight control eating behaviors will be measured with a questionnaire.

    Measured: Baseline, 6, 12, and 18 months.

  5. Change in Dietary Weight Loss Program Attendance and Adherence

    Dietary weight loss program attendance and adherence will be assessed throughout the 18 month program.

    Measured: 18 months

  6. Change in Exercise Program Attendance and Adherence

    Exercise program attendance and adherence will be assessed throughout the 18 month program.

    Measured: 18 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Nov 2013 (estimated)
  2. Study startNov 2013
  3. Primary completionSep 2018
  4. Study completionSep 2018

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
170 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01985568
Sponsor's protocol ID
13-1550
Other IDs
R01DK097266
Status last verified
Sep 2023
First submitted
24 Oct 2013
Last updated
28 Sep 2023
Results posted
No
Data monitoring committee
No
Individual data sharing
No

Publications

  • Creasy SA, Ostendorf DM, Kaizer L, Rosenberg R, Breit MJ, Bessesen DH, Melanson EL, Catenacci VA. Effect of physical activity on changes in weight and aerobic capacity during an 18-month behavioral weight loss intervention. Int J Behav Nutr Phys Act. 2025 May 21;22(1):57. doi: 10.1186/s12966-025-01754-3.

    PubMed 40399945
  • Creasy SA, Ostendorf DM, Blankenship JM, Grau L, Arbet J, Bessesen DH, Melanson EL, Catenacci VA. Effect of sleep on weight loss and adherence to diet and physical activity recommendations during an 18-month behavioral weight loss intervention. Int J Obes (Lond). 2022 Aug;46(8):1510-1517. doi: 10.1038/s41366-022-01141-z. Epub 2022 May 16.

    PubMed 35577898
  • Ostendorf DM, Schmiege SJ, Conroy DE, Phelan S, Bryan AD, Catenacci VA. Motivational profiles and change in physical activity during a weight loss intervention: a secondary data analysis. Int J Behav Nutr Phys Act. 2021 Dec 4;18(1):158. doi: 10.1186/s12966-021-01225-5.

    PubMed 34863198
  • Catenacci VA, Ostendorf DM, Pan Z, Bing K, Wayland LT, Seyoum E, Stauffer BL, Phelan S, Creasy SA, Caldwell AE, Wyatt HR, Bessesen DH, Melanson EL. The Impact of Timing of Exercise Initiation on Weight Loss: An 18-Month Randomized Clinical Trial. Obesity (Silver Spring). 2019 Nov;27(11):1828-1838. doi: 10.1002/oby.22624. Epub 2019 Sep 29.

    PubMed 31565869

Questions about this trial

What is this clinical trial studying?

A study testing Sequential BT and Standard BT in people with Obesity, run by University of Colorado, Denver at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 13 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 28 Sep 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Body Weight (time frame: Baseline, 3, 6, 9, 12, 15, and 18 months.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01985568, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Sep 2023.

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