Clinical trial NCT00962117: Relationship Between Dopamine Genetics, Food Reinforcement, Energy Intake and Obesity
Official title: Food Reinforcement Genotype Interactions and Eating
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obesity
Keywords: Food Reinforcement
Energy Intake
Obesity
Dopamine
Lead sponsor: State University of New York at Buffalo
Sponsor class: OTHER
First posted: 2009-08-19
Enrollment: 310
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: Subjects will be recruited from newspaper ads, posters on campus and in community settings, web based recruitment (ads on Craig's list and on the department's website) and direct mail targeted to community residents between 18-50 years of age.

Brief summary: The purpose of the study is to determine whether the presentation of various foods produces an increase or decrease in responses on a motivational computer task. In addition, the study determines if energy intake or motivation to obtain food is related to the dopamine receptor genotype.

Detailed description: One of the most important research areas in obesity is developing a better understanding of individual differences in factors that influence excess energy intake and positive energy balance. One key to understanding these individual differences is determining what factors underlie the motivation to eat. We have demonstrated in a series of studies that obese adults and children are more motivated to work for palatable, favorite foods than leaner peers and that those high in food reinforcement consume more food in an ad libitum eating task than those who do not find food as reinforcing. Dopamine (DA) is one of the major neurotransmitters involved in establishing the reinforcing value of food, and low levels of dopamine activity and a reduction in the number of DA receptors is associated with obesity. The general aim of the proposed research is to build upon this research to examine relationships between food reinforcement, obesity, and polymorphisms of genes within the dopaminergic system.

Eligibility criteria: Inclusion Criteria:

* Non-smokers
* 18-50 years of age
* No known eating disorder
* Moderate liking for study foods
* No current diagnosis of psychiatric disorder (e.g., anxiety or depression)
* Not on medications that would interfere with appetite (e.g., methylphenidate) or dopaminergic activity
* Non-diabetics

Exclusion Criteria:

* Smoker
* Pregnant women
* Current diagnosis of a psychiatric or eating disorder
* Dietary restrictions that would interfere with participation
* On medications that could interfere with appetite or olfactory responsiveness or use of antidepressants or any medication or dietary supplement that could affect appetite or dopaminergic activity
* Excessive use of alcohol (\>21 drinks/week), alcoholism,current addiction to opiates, cocaine or stimulants

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: SUNY Buffalo
name: Leonard H Epstein, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lin H, Carr KA, Fletcher KD, Epstein LH. Food reinforcement partially mediates the effect of socioeconomic status on body mass index. Obesity (Silver Spring). 2013 Jul;21(7):1307-12. doi: 10.1002/oby.20158. Epub 2013 Jun 11.
citation: Epstein LH, Carr KA, Lin H, Fletcher KD, Roemmich JN. Usual energy intake mediates the relationship between food reinforcement and BMI. Obesity (Silver Spring). 2012 Sep;20(9):1815-9. doi: 10.1038/oby.2012.2. Epub 2012 Jan 13.
citation: Epstein LH, Lin H, Carr KA, Fletcher KD. Food reinforcement and obesity. Psychological moderators. Appetite. 2012 Feb;58(1):157-62. doi: 10.1016/j.appet.2011.09.025. Epub 2011 Oct 8.
citation: Epstein LH, Carr KA, Lin H, Fletcher KD. Food reinforcement, energy intake, and macronutrient choice. Am J Clin Nutr. 2011 Jul;94(1):12-8. doi: 10.3945/ajcn.110.010314. Epub 2011 May 4.