Trial Outcomes & Findings for Neuronal and Behavioral Effects of Implicit Priming in Obese Individuals (NCT NCT02347527)
NCT ID: NCT02347527
Last Updated: 2022-09-07
Results Overview
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.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
92 participants
Primary outcome timeframe
Baseline to within 10 minutes post-intervention
Results posted on
2022-09-07
Participant Flow
For the "Behavioral-Only" sample, participants were recruited via flyer advertisement in Aurora, CO, between May 2013 and March 2014. For the "MRI" sample, participants were recruited via email and flyer advertisement in Aurora, CO, between May 2015 and August 2019.
47 participants were in the "MRI sample" and 45 were in the "Behavioral-only sample," for a total of 92 unique study participants.
Participant milestones
| Measure |
Active Implicit Priming (MRI Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the priming intervention during fMRI scanning.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes. This group completed the priming intervention during fMRI scanning.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
|---|---|---|---|---|
|
Overall Study
STARTED
|
25
|
22
|
23
|
22
|
|
Overall Study
Completed Intervention
|
24
|
21
|
23
|
22
|
|
Overall Study
Included in Analyses
|
22
|
19
|
22
|
20
|
|
Overall Study
COMPLETED
|
22
|
19
|
22
|
20
|
|
Overall Study
NOT COMPLETED
|
3
|
3
|
1
|
2
|
Reasons for withdrawal
| Measure |
Active Implicit Priming (MRI Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the priming intervention during fMRI scanning.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes. This group completed the priming intervention during fMRI scanning.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
|---|---|---|---|---|
|
Overall Study
MRI not completed due to technical difficulties
|
1
|
0
|
0
|
0
|
|
Overall Study
MRI stopped due to participant anxiety
|
0
|
1
|
0
|
0
|
|
Overall Study
Excluded from analyses due to excess movement during MRI scan
|
1
|
1
|
0
|
0
|
|
Overall Study
Excluded from analyses due to technical difficulties during the study visit
|
1
|
0
|
1
|
2
|
|
Overall Study
Excluded from analyses due to non-compliance with study procedures
|
0
|
1
|
0
|
0
|
Baseline Characteristics
Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
Baseline characteristics by cohort
| Measure |
Active Implicit Priming (MRI Sample)
n=22 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the intervention during fMRI scan.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
n=19 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes. This group completed the intervention during fMRI scan.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
n=22 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
n=20 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Total
n=83 Participants
Total of all reporting groups
|
|---|---|---|---|---|---|
|
Age, Continuous
|
41.5 years
STANDARD_DEVIATION 14.4 • n=22 Participants
|
37.3 years
STANDARD_DEVIATION 13.6 • n=19 Participants
|
30.7 years
STANDARD_DEVIATION 6.0 • n=22 Participants
|
35.1 years
STANDARD_DEVIATION 11.88 • n=20 Participants
|
36.15 years
STANDARD_DEVIATION 4.5 • n=83 Participants
|
|
Sex: Female, Male
Female
|
18 Participants
n=22 Participants
|
10 Participants
n=19 Participants
|
14 Participants
n=22 Participants
|
12 Participants
n=20 Participants
|
54 Participants
n=83 Participants
|
|
Sex: Female, Male
Male
|
4 Participants
n=22 Participants
|
9 Participants
n=19 Participants
|
8 Participants
n=22 Participants
|
8 Participants
n=20 Participants
|
29 Participants
n=83 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
5 Participants
n=22 Participants
|
1 Participants
n=19 Participants
|
3 Participants
n=22 Participants
|
4 Participants
n=20 Participants
|
13 Participants
n=83 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
9 Participants
n=22 Participants
|
8 Participants
n=19 Participants
|
19 Participants
n=22 Participants
|
16 Participants
n=20 Participants
|
52 Participants
n=83 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
8 Participants
n=22 Participants
|
10 Participants
n=19 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=20 Participants
|
18 Participants
n=83 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=22 Participants
|
0 Participants
n=19 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=83 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=22 Participants
|
3 Participants
n=19 Participants
|
2 Participants
n=22 Participants
|
1 Participants
n=20 Participants
|
6 Participants
n=83 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=22 Participants
|
0 Participants
n=19 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=83 Participants
|
|
Race (NIH/OMB)
Black or African American
|
2 Participants
n=22 Participants
|
0 Participants
n=19 Participants
|
0 Participants
n=22 Participants
|
1 Participants
n=20 Participants
|
3 Participants
n=83 Participants
|
|
Race (NIH/OMB)
White
|
16 Participants
n=22 Participants
|
13 Participants
n=19 Participants
|
17 Participants
n=22 Participants
|
14 Participants
n=20 Participants
|
60 Participants
n=83 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=22 Participants
|
0 Participants
n=19 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=20 Participants
|
0 Participants
n=83 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
4 Participants
n=22 Participants
|
3 Participants
n=19 Participants
|
3 Participants
n=22 Participants
|
4 Participants
n=20 Participants
|
14 Participants
n=83 Participants
|
|
Region of Enrollment
United States
|
22 participants
n=22 Participants
|
19 participants
n=19 Participants
|
22 participants
n=22 Participants
|
20 participants
n=20 Participants
|
41 participants
n=83 Participants
|
|
BMI
|
30.8 kg/m2
STANDARD_DEVIATION 5.5 • n=22 Participants
|
28.8 kg/m2
STANDARD_DEVIATION 3.0 • n=19 Participants
|
22.5 kg/m2
STANDARD_DEVIATION 3.0 • n=22 Participants
|
24.2 kg/m2
STANDARD_DEVIATION 4.4 • n=20 Participants
|
29.8 kg/m2
STANDARD_DEVIATION 4.6 • n=83 Participants
|
|
Baseline food image ratings
|
62.2 units on a scale
STANDARD_DEVIATION 16.0 • n=19 Participants • Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
|
52.5 units on a scale
STANDARD_DEVIATION 14.3 • n=17 Participants • Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
|
54.8 units on a scale
STANDARD_DEVIATION 13.1 • n=22 Participants • Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
|
50.2 units on a scale
STANDARD_DEVIATION 22.5 • n=20 Participants • Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
|
55.1 units on a scale
STANDARD_DEVIATION 14.7 • n=78 Participants • Due to technical difficulties, food cue ratings were not collected for 5 participants in the MRI sample groups (sample size for this measure for the MRI sample groups: active, n = 19; control n = 17).
|
PRIMARY outcome
Timeframe: Baseline to within 10 minutes post-interventionFood 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.
Outcome measures
| Measure |
Active Implicit Priming (MRI Sample)
n=19 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the intervention during an fMRI scan.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
n=17 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.This group completed the intervention during an fMRI scan.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
n=22 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
n=20 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
|---|---|---|---|---|
|
Change in Food Image Ratings
|
-5.1 Score change from baseline
Standard Error 2.5
|
-.3 Score change from baseline
Standard Error 2.2
|
-6.8 Score change from baseline
Standard Error 1.3
|
-2.7 Score change from baseline
Standard Error 1.4
|
PRIMARY outcome
Timeframe: Baseline to post-interventionNeuronal 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.
Outcome measures
| Measure |
Active Implicit Priming (MRI Sample)
n=21 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the intervention during an fMRI scan.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
n=19 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.This group completed the intervention during an fMRI scan.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
|---|---|---|---|---|
|
Neuronal Response to Food Cues
|
0.21 % BOLD signal change from baseline
Standard Deviation 0.45
|
-0.07 % BOLD signal change from baseline
Standard Deviation .34
|
—
|
—
|
SECONDARY outcome
Timeframe: 1 hour post-interventionFood intake during ad-lib lunch (kcals)
Outcome measures
| Measure |
Active Implicit Priming (MRI Sample)
n=19 Participants
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect. This group completed the intervention during an fMRI scan.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (MRI Sample)
n=17 Participants
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.This group completed the intervention during an fMRI scan.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
Active Implicit Priming (Behavioral-only Sample)
Participants completed active implicit priming, in which food images were implicitly primed (i.e., below conscious awareness) with images of positive or negative affect.
Active Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of positive or negative valence.
|
Control Implicit Priming (Behavioral-only Sample)
Participants completed a control implicit priming intervention, which matched the active intervention, but with neutral stimuli as primes.
Control Implicit Priming: A 10-minute implicit priming intervention, associating food images with images of neutral valence.
|
|---|---|---|---|---|
|
Food Intake
|
959.03 kcals
Standard Deviation 343.53
|
860.38 kcals
Standard Deviation 361.99
|
—
|
—
|
Adverse Events
Active Implicit Priming (MRI Sample)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Control Implicit Priming (MRI Sample)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Active Implicit Priming (Behavioral-only Sample)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Control Implicit Priming (Behavioral-only Sample)
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Dr. Kristina Legget
University of Colorado School of Medicine
Phone: 3037245809
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place