Weight Loss and Cognitive Function in Adults

Study Overview
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Brief Summary
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More than two-thirds of middle-aged and older adults are overweight, which places them at greater risk of disability and higher medical expenses. Lifestyle interventions which promote weight loss for this population are needed. However, it is not known how different weight loss approaches impact brain (cognitive) functions, such as memory and attention. The investigator's investigation aims to improve adherence to a hypocaloric diet prescription through improved attention and inhibitory control, reduced hunger, and increased satiety. The objectives of this pilot study are to: 1) determine the feasibility and establish proof-of-concept; 2) establish proficiency and feasibility of the proposed cognitive function assessments; and 3) obtain preliminary data for effect size generation.

Official Title
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Weight Loss and Cognitive Function in Middle-Aged and Older Adults

Conditions
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Overweight and Obesity

Intervention / Treatment
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* Behavioral: Hypocaloric diet with hunger reduction strategy
* Behavioral: Hypocaloric diet without hunger reduction strategy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Overweight or obese, BMI 25-40 kg/m^2 Able to use a computer, keyboard, and mouse Exclusion Criteria: Uncontrolled hypertension Orthopedic injury Other conditions that preclude participation in a walking program Previous participation in psychology research which involved computerized cognitive testing Diabetes which requires insulin

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hypocaloric diet with hunger reduction strategy<br>Participants will be prescribed a hypocaloric diet with additional instructions to promote hunger reduction. The hypocaloric diet will range 1200-1500 kcal/d, and will be based upon the 2015 US Dietary Guidelines for Americans. Dietary instructions will be provided by a Registered Dietitian. | Behavioral: Hypocaloric diet with hunger reduction strategy<br>* Participants will be counseled to consume a hypocaloric diet during the 4-week weight loss phase. Counseling will include specific instructions on a dietary manipulation which may reduce hunger, in order to facilitate dietary adherence.This will include tracking of the strategy. They will also be provided a pedometer and instructed to attain 10,000 steps per day.<br>|
| Active Comparator: Hypocaloric diet without hunger reduction strategy<br>Participants will only be prescribed a hypocaloric diet. The hypocaloric diet will range 1200-1500 kcal/d, and will be based upon the 2015 US Dietary Guidelines for Americans. Dietary instructions will be provided by a Registered Dietitian. | Behavioral: Hypocaloric diet without hunger reduction strategy<br>* Participants will be counseled to consume a hypocaloric diet during the 4-week weight loss phase. They will also be provided a pedometer and instructed to attain 10,000 steps per day.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cognitive function changes - attention | Computerized tasks will score each participant's performance for attention at baseline and after both the 4-week weight loss and weight maintenance phases. | 30-min measurement per session | 
| Cognitive function changes - inhibitory control | Computerized tasks will score each participant's performance for inhibitory control at baseline and after both the 4-week weight loss and weight maintenance phases. | 30-min measurement per session | 
| Weight change | Weight will be measured on a scale at baseline and after both the 4-week weight loss and weight maintenance phases. | 5-min measurement per session | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Perceived hunger | The Visual Analog Scale (VAS) survey will be used to measure hunger at baseline and after both the 4-week weight loss and weight maintenance phases. Participants make a mark on a 100 mm line that corresponds to their subjective feelings (range of score is 0-100). The line is anchored by descriptors that are polar opposites (not at all hungry to extremely hungry). The score is determined by using the place on the line where the mark is made by the participants. | 15-minute measurement per session | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Weight loss, Cognitive function, Weight maintenance