Neuronal and Behavioral Effects of Implicit Priming in Obese Individuals

Obesity Clinical Trial

Official title:

Neuronal and Behavioral Effects of Implicit Priming in Obese Individuals

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02347527
• Other study ID #: 13-1786
• Secondary ID: R21DK102052P30DK
• Status: Completed
• Phase: N/A
• Start date: May 2013
• Est. completion date: August 2019

Study information

• Verified date: August 2022
• Source: University of Colorado, Denver
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The overall goals of this project are to determine the impact of an implicit priming intervention, designed to alter food perceptions, on both brain responses to food and on food intake behaviors in overweight/obese individuals. The investigators hypothesized that this bottom-up sensory-level conditioning approach would effectively result in reduced preference for high-calorie foods.

Description:

One factor that may contribute to susceptibility to obesity is a high responsivity to high-calorie foods in terms of cognitive factors such as emotional associations, reward value or reinforcing properties of food. Many of these processes involve learned associations thought to develop via classical conditioning through repeated pairings with external stimuli, which can influence food preferences and intake. As such, improving our understanding of the neuronal mechanisms underlying these processes and attempting to modify them may be a useful strategy to promote weight loss and maintenance. Therefore, the proposed study aims to investigate the effects of altering food perception on neuronal responses and food intake behaviors by using implicit priming, in which positively or negatively valenced images are presented immediately prior to food images, but are not consciously perceived. The project goals are to determine the impact of the implicit priming intervention on both brain responses to food cues and on food intake behaviors in overweight/obese individuals. Food image ratings were assessed before and after either (a) an active implicit priming intervention or (b) a control intervention. One group of participants (n = 47; "MRI sample") completed the intervention during an fMRI scan and completed a visual food cues task both before and after the intervention (during fMRI), to assess intervention-related change in neuronal responses to food cues. In this group, food intake measures were also taken following fMRI. In a separate group of participants (n = 45; "Behavioral-only sample"), the primary outcome measure was the change in food image ratings from pre- to post-intervention; fMRI and measures of food intake were not assessed in this group.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 92
• Est. completion date: August 2019
• Est. primary completion date: August 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 21 Years to 65 Years

Eligibility

Inclusion Criteria:

• Overweight/obese adults
• Healthy weight adults

Exclusion Criteria:

• Vegetarian, vegan, or having other wide-ranging food restrictions
• Currently dieting
• MRI exclusion criteria, if in MRI sample (e.g., claustrophobia, metal in the body)

Related Conditions & MeSH terms

• Feeding Behavior
• Obesity
• Overweight

Intervention

Behavioral:
• Active Implicit Priming
A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
• Control Implicit Priming
A 10-minute implicit priming intervention, associating food images with images of neutral valence.

Locations

Country	Name	City	State
United States	University of Colorado Anschutz Medical Campus	Aurora	Colorado

Sponsors (2)

Lead Sponsor	Collaborator
University of Colorado, Denver	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Food Image Ratings	Food image ratings (high-calorie foods) change from baseline, measured within 10 minutes post-intervention. Food images are rated on "desire to eat" by visual analogue scale (0-100; higher scores mean greater desire to eat). Negative values indicate reduced scores post-intervention compared to baseline, with greater numbers indicating greater reduction.	Baseline to within 10 minutes post-intervention
Primary	Neuronal Response to Food Cues	Neuronal response while viewing visual food cues will be measured using functional magnetic resonance imaging (fMRI). Primary outcome was insula response change from baseline, as measured within 20 minutes after the intervention. A bilateral region of interest (ROI) for the insula was defined anatomically, with mean difference from baseline to post-intervention (% BOLD signal change) calculated across all voxels for that ROI. A positive number indicates a reduced response (with higher numbers indicating greater change) and a negative number indicates an increased response.	Baseline to post-intervention
Secondary	Food Intake	Food intake during ad-lib lunch (kcals)	1 hour post-intervention