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Completed

NCT Number: NCT02347527

Neuronal and Behavioral Effects of Implicit Priming in Obese Individuals

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.

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Key information

Conditions

Feeding Behavior Behavior Behavior, Animal Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

21 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Colorado Anschutz Medical Campus

Aurora, Colorado, 80045, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Active Implicit Priming

Behavioral

A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.

Control Implicit Priming

Behavioral

A 10-minute implicit priming intervention, associating food images with images of neutral valence.

Primary outcomes

  1. Change in Food Image Ratings

    Time frame: Baseline to within 10 minutes post-intervention

    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.

  2. Neuronal Response to Food Cues

    Time frame: Baseline to post-intervention

    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.

Secondary outcomes

  1. Food Intake

    Time frame: 1 hour post-intervention

    Food intake during ad-lib lunch (kcals)

Sponsors and collaborators

Lead sponsor

University of Colorado, Denver

Other

Collaborators

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

Registry information

Important dates

Study start
2013
Primary completion
2019
Study completion
2019
First posted
Jan 27, 2015
Registry last updated
Sep 7, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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