Integrating Small Changes and Positive Psychology to Improve Treatment Readiness: A Weight Loss Trial

The study is designed to compare short- and long-term changes in body weight (kg) and subjective well-being in adult females with obesity who have been randomized to receive one of two 6-month treatment conditions: INSPIRE or Small Changes. The Small Changes approach is an evidence-based behavioural weight management program that uses relative and modest changes in nutrition and physical activity to produce a caloric deficit. The INSPIRE program is a modification of the Small Changes program that spends the first four weeks on improving well-being via psychological interventions.

Rates of obesity continues to rise in Canada and worldwide, which is related to the presence and increased severity of multiple co-morbid illnesses as well as a reduction in overall quality and quantity of life. Traditional behavioural interventions have demonstrated efficacy in producing initial weight loss; however, a continued challenge for these programs is long-term weight loss maintenance. The Small Changes program is an alternative approach to weight loss that encourages modest changes to nutrition and physical activity that are sustainable long-term. Although promising, this approach has failed to consistently demonstrate clinically significant weight loss. It has been suggested that psychological factors, such as low levels of subjective well-being (negative affect, positive affect, and life satisfaction), may work in opposition of an individual's weight management goals. Thus, the integration of psychological interventions with a Small Changes approach has the potential to improve well-being and weight loss concurrently. Based on previous research, psychological interventions may be effectively utilized if they are implemented at the beginning of an intervention where early changes in well-being promote greater adherence to health behaviour change. To date, no behavioural intervention that integrates psychological approaches at treatment outset has been evaluated. The primary aim of the study is to determine the feasibility, acceptability, and efficacy of a novel group-based integrative behavioural and psychological intervention (INSPIRE) on change in weight and subjective well-being outcomes compared to an evidence-based behavioural intervention for weight loss (Small Changes).

Eligibility Criteria:
Inclusion Criteria:

* Female between the ages of 25 to 75
* BMI between 30 and 45
* Not currently participating in any other weight management programs
* Self-reports wanting to lose weight
* Willing to follow recommendations in the study protocol and attend weekly group intervention for 12 weeks and a 3-month follow-up group (one in-person group per month and one phone call per month)
* Ability to attend 4 assessment appointments over the course of the study period (at baseline, 3-months, 6-months, 12-months).
* Willing to be randomized into any of the two study arms and willing to adhere to guidelines and recommendations associated with the study arm they are randomized into

Exclusion Criteria:

* Cannot commit to weekly group times. Participants must be available for at least one group time of each intervention arm in order to be eligible to participate.
* Participated in a weight loss intervention in the past six months
* Participants who are pregnant (or less than 6 months post partum) or planning to become pregnant in the next 12 months
* Weight loss of \> 5kg (\~11 lb) in the previous 6 months
* History of, or current, clinically diagnosed eating disorder or exhibiting clinical symptoms of an eating disorder but undiagnosed (EDE-Q ≥ 4.0 unless clinical judgement indicates otherwise)
* Reported health problems that make weight loss or unsupervised exercise unsafe or unreasonable (as measured by the PAR-Q+) where a doctor's note is not provided
* Resting systolic blood pressure \>160 mmHg or resting diastolic blood pressure \>100 mmHg
* If any of the following medical conditions are present: Insulin dependent diabetes; Previous surgical procedure for weight loss; Major surgery within the previous 6 months; A history of heart problems (e.g., angina, bypass surgery, myocardial infarction) within the previous 6 months; Implanted cardiac defibrillator or pacemaker; Currently (or within the past 5 years) being treated for cancer; Inflammatory Bowel Disease (i.e., chronic inflammatory gastrointestinal disease such as Crohn's Disease or Ulcerative Colitis); Chronic Pain (e.g., fibromyalgia) that would prevent the participant from engaging in physical activity
* The participant is currently experiencing elevated symptoms of depression
* The participant is planning to move within the study period
* The participant consumes more than 14 alcoholic drinks per week or more than 3 drinks per day