Behavioral Therapies for Weight Loss

Overseen By Brie Sullivan

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: Fred Hutchinson Cancer Research Center

Disqualifiers: Binge eating, Severe depression, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 28

Duration: 12 months

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine if Acceptance and Commitment Therapy (ACT), delivered by phone, aids weight loss more effectively than standard behavioral therapy (SBT). ACT focuses on managing cravings and emotions while encouraging changes that align with personal values. Participants will receive coaching calls over 12 months, with different schedules for ACT and SBT groups. The trial seeks individuals in the U.S. who are overweight or obese, wish to lose weight soon, and have access to a phone and email. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants the opportunity to contribute to a potentially groundbreaking weight loss treatment.

Will I have to stop taking my current medications?

The trial information does not specify if you need to stop taking your current medications. However, if you have changed the dosage of prescription medications that affect weight or appetite in the past 3 months, you may not be eligible to participate.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that Acceptance and Commitment Therapy (ACT) is generally safe and well-received for managing weight. Studies indicate that ACT can be as effective, or even more effective, than standard treatments for weight loss. In previous trials, about 23.51% of participants discontinued, a typical rate for behavior change programs, suggesting that ACT is fairly well-tolerated.

Standard Behavioral Therapy (SBT) is a proven method for weight loss, used in both research and clinical settings. Often considered a gold standard, it usually involves lifestyle changes like diet and exercise, indicating it is also safe and well-tolerated.

Both ACT and SBT have been shown to aid weight loss without causing serious side effects. Participants in studies generally respond well to these therapies. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these telephone-based behavioral therapies for weight loss because they offer a convenient and structured approach that might increase accessibility and adherence. Unlike traditional in-person weight loss programs, these interventions provide regular support through scheduled calls, which can fit more easily into busy lifestyles. The use of Acceptance and Commitment Therapy (ACT) and Standard Behavioral Therapy (SBT) by phone allows for personalized coaching without the need for travel, potentially reaching a wider audience who may not have access to face-to-face services. This method could lead to more sustainable weight loss by integrating psychological support directly into participants' daily lives.

What evidence suggests that this trial's therapies could be effective for weight loss?

This trial will compare Acceptance and Commitment Therapy (ACT) with Standard Behavioral Therapy (SBT) for weight loss. Research has shown that ACT, which participants in this trial may receive, can assist with weight loss. One study found that participants lost an average of 0.71% of their starting weight, indicating ACT's potential in reducing weight. ACT also improves eating habits and overall quality of life by addressing the mental aspects of obesity.

Meanwhile, participants in another arm of this trial will receive SBT, which typically results in a weight loss of about 5–8% after a year. This method is well-known for its effectiveness in weight loss. Both therapies offer benefits, but ACT might provide additional psychological advantages. ^{2 6 7 8 9}

Who Is on the Research Team?

Jonathan B Bricker

Principal Investigator

Fred Hutch/University of Washington Cancer Consortium

Are You a Good Fit for This Trial?

This trial is for US residents who are overweight or obese (BMI >= 27 but <= 45.5), not pregnant, and without certain medical conditions like severe heart disease, uncontrolled hypertension, or cancer. Participants must be willing to try a new weight loss therapy over the phone, have daily access to a phone and email, can read English, aren't on other weight loss programs or studies, and haven't had significant weight changes recently.

Inclusion Criteria

Not participating in or planning to participate in other weight loss programs

For outcome data retention, eligibility criteria included: Willing to complete follow-up surveys, and provide email, phone, and mailing address

I have not lost more than 5% of my weight in the last 6 months.

Exclusion Criteria

I do not meet the specific requirements listed for the trial.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either ACT or SBT telephone coaching over the course of 12 months, with calls 1-16 weekly, calls 17-23 biweekly, and calls 24-25 monthly.

12 months

25 calls (telephone)

Follow-up

Participants are monitored for weight loss, physical activity, and dietary intake at 6, 12, and 24 months post-randomization.

24 months

3 follow-up assessments (remote)

What Are the Treatments Tested in This Trial?

Interventions

• Telephone-Based Intervention

Trial Overview The study tests if Acceptance and Commitment Therapy delivered by telephone helps with weight loss better than standard behavioral therapy. It involves accepting cravings while making committed changes aligned with personal values. Participants will be randomly assigned to one of these two approaches.

How Is the Trial Designed?

Group I: Arm I (ACT) Experimental Treatment 2 Interventions

Participants receive ACT telephone coaching over the course of 12 months, calls 1-16 weekly, calls 17-23 biweekly, and calls 24-25 monthly. Call 1 is 30 minutes in duration, while calls 2-25 are each 15-20 minutes in duration.

Group II: Arm II (SBT) Active Control 2 Interventions

Participants receive SBT telephone coaching over the course of 12 months, calls 1-16 weekly, calls 17-23 biweekly, and calls 24-25 monthly. Call 1 is 30 minutes in duration, while calls 2-25 are each 15-20 minutes in duration.

Telephone-Based Intervention is already approved in United States for the following indications:

Approved in United States as Telephone-Based Smoking Cessation Intervention for:

• Smoking cessation in pregnant women
• Prevention of low birth weight

Who Is Running the Clinical Trial?

Fred Hutchinson Cancer Research Center

Lead Sponsor

Trials

444

Recruited

148,000+

Fred Hutchinson Cancer Center

Lead Sponsor

Trials

583

Recruited

1,341,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

In a study of 837 daily smokers, those receiving telephone care had a significantly higher 6-month smoking cessation rate (13.0%) compared to those receiving standard care (4.1%), indicating that telephone counseling is a more effective intervention.

Participants in the telephone care group were much more likely to engage in counseling programs (97.1% vs 24.0%) and use smoking cessation medications (89.6% vs 52.3%), suggesting that telephone care enhances both behavioral and pharmacological support for quitting smoking.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Benefits of telephone care over primary care for smoking cessation: a randomized trial. An, LC., Zhu, SH., Nelson, DB., et al.[2022]

Telephonic tobacco cessation coaching significantly improved quit rates among participants (31%) compared to matched controls (23%), demonstrating its effectiveness in real-world clinical settings.

Participants in the coaching program also filled prescriptions for tobacco cessation medications at a much higher rate (47%) than those who received no treatment (6%), indicating that the coaching not only helped with quitting but also encouraged the use of cessation aids.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Telephone-Based Coaching. Boccio, M., Sanna, RS., Adams, SR., et al.[2022]

A telephone-based lifestyle program for weight loss led to a significant average weight loss of 4.25 kg over 12 months among participants, indicating its effectiveness as an alternative to face-to-face obesity treatments.

The program was well-accepted, especially by men, and resulted in additional health benefits such as reduced abdominal girth and lower cholesterol levels, suggesting it can improve overall metabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

One-Year Weight Loss with a Telephone-Based Lifestyle Program. Holzapfel, C., Merl, M., Stecher, L., et al.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9918584/

Effectiveness of acceptance and commitment therapy on ... ACT was found to be effective in improving weight loss in terms of BMI (k = 6, WMD = − .50, 95% CI = − .90; − .11, t = − 3.25, p = .20, I 2

2. link.springer.com link.springer.com/article/10.1007/s13679-025-00634-y

Acceptance and Commitment Therapy for Obesity Current data indicate that ACT-based interventions produce comparable, or, in some cases, superior weight loss compared to standard behavioral interventions.

3. sciencedirect.com sciencedirect.com/science/article/pii/S2212144724001078

An acceptance and commitment therapy and mindfulness ... ACT and mindfulness could reduce the impact of weight on quality of life over time. •. ACT and mindfulness could improve dietary habits of people with obesity.

4. nature.com nature.com/articles/s41366-025-01759-9

Individual participant data meta-analysis of eating ... There was a difference of mean percentage weight change from baseline to the end of intervention of −0.71% [95% CI −1.29, −0.03] in the ACT ...

5. sites.brown.edu sites.brown.edu/publichealthjournal/2024/03/17/analyzing-technology-supported-acceptance-and-commitment-therapy-for-obesity/

Analyzing Technology-Supported Acceptance and ... Overall, ACT has been found to be effective in treating psychological aspects of obesity and partially in addressing weight loss.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12064586/

Acceptance and Commitment Therapy for Obesity - PMC Current data indicate that ACT-based interventions produce comparable, or, in some cases, superior weight loss compared to standard behavioral interventions.

7. journals.plos.org journals.plos.org/plosone/article?id=10.1371/journal.pone.0282849

A randomised controlled feasibility trial of acceptance and ... A randomised controlled trial of 10 sessions of group ACT or Usual Care Support Group control (SGC) was delivered 15–18 months post bariatric surgery.

8. sciencedirect.com sciencedirect.com/science/article/pii/S2212144723001266

The acceptability, feasibility and preliminary efficacy of ... ACT for weight management showed high acceptability among adolescents. Studies demonstrate some evidence that ACT may yield support for weight management.

9. onlinelibrary.wiley.com onlinelibrary.wiley.com/doi/10.1002/jclp.70021

Acceptance and Commitment Therapy for Body ... A majority of studies (75%) had low to medium risk of bias. The mean dropout rate across ACT interventions was 23.51%. Discussion. These results ...