The Chocolate Study 2.0

April 8, 2025 updated by: USDA Grand Forks Human Nutrition Research Center

Assessment of Dopaminergic Neurotransmission in Response to Tasting Chocolate (The Chocolate Study 2.0)

The purpose of this study is to test how the brain responds when enjoyable foods such as chocolate are consumed. The investigators know that eating certain types of foods can make an individual want to keep eating even when he or she is full. The chemical in the brain that causes this is called dopamine. The investigators can measure this response by looking at changes to how an individual's eye responds to light.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The overall objective of this study is to determine dopamine (DA) neuromodulation (changes in b-wave amplitude as measured by electroretinography (ERG)) in response to consuming a highly reinforcing food (chocolate). The investigators hypothesize that orosensory stimulation with chocolates with increasing sugar content will increase the beta wave (b-wave) amplitude and the increase in the b-wave amplitude will correlate with score changes on the Psychophysical Effects Questionnaire (PEQ). This will be accomplished by testing different chocolates (extreme dark (90% cocoa), dark (70% cocoa), milk (38% cocoa), and white (0% cocoa)) on different days using 1.0 cd∙s/m2 flash luminance energy.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Dakota
      • Grand Forks, North Dakota, United States, 58203
        • USDA Grand Forks Human Nutrition Research Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 30 years (Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Community sample

Description

Inclusion Criteria:

  • BMI 20-24.9 kg/m2
  • ability to understand and sign the consent form
  • availability of transportation (i.e., participants must be able to provide their own transportation to the Grand Forks Human Nutrition Research Center)
  • be free of any major illness/disease

Exclusion Criteria:

  • food allergies
  • participation in a weight loss diet/exercise program
  • pregnancy
  • lactation
  • metabolic illness/disease (diabetes, renal failure, thyroid illness, hypertension)
  • eye illness/disease (narrow angle glaucoma, macular degeneration, retinal detachment, cataracts)
  • psychiatric, neurological or eating disorders (schizophrenia, depression, Parkinson's Disease, Huntington's Disease, cerebral palsy, stroke, epilepsy, anorexia nervosa or bulimia nervosa)
  • taking any type of prescription medication with the exception of oral contraceptives and antihyperlipidemia agents

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Other

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Chocolate
Participants will be asked to taste commercially available chocolate varying in sugar, fat and percent cocoa.
Other: Chocolate
Participants will be asked to taste commercially available chocolate varying in sugar, fat and percent cocoa (extreme dark (90%), dark (70%), milk (38%), and white (0%)).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Retinal dopamine response to oral stimuli
Time Frame: 30 minutes
Electroretinograph b-wave amplitude will increase in response to increases in the amount of sugar in the chocolate.
30 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Correlation between b-wave amplitude and PEQ scores
Time Frame: 30 minutes
The change in b-wave amplitude will positively correlate to Psychophysical Effects Questionnaire (PEQ) score changes.
30 minutes
Correlation between b-wave amplitude and habitual dietary intake
Time Frame: 30 minutes
A preference for dark chocolate and/or a greater habitual fat intake will positively correlate with the retinal dopamine-mediated response to the dark chocolates (90% and 70% cocoa) and a preference for milk chocolate and/or a greater habitual added sugar will positively correlate with the retinal dopamine-mediated response to the milk and white chocolates. Higher amounts of artificial sweetener intake will will positively correlate with the retinal dopamine-mediated response to the milk and white chocolates. Greater habitual chocolate intake will positively correlate to changes in b-wave amplitude.
30 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
USDA Grand Forks Human Nutrition Research Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Shanon Casperson, PhD, USDA Grand Forks Human Nutrition Research Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 25, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 5, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 5, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 25, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 25, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 30, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 11, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • GFHNRC218

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings