Opiates, overeating and obesity: a psychogenetic analysis.
OBJECTIVE
This study provides an original perspective on the associations among endogenous opiates, overeating and obesity. The aim was to assess whether variability in the OPRM1 gene, as assessed by seven single-nucleotide polymorphisms, relates to individual differences in the preference for sweet and fatty foods. We also anticipated that these food preferences would be positively associated with binge eating, hedonic eating and emotionally driven eating-patterns of overeating that would, in turn, predict higher body mass index (BMI).


METHODS
Analysis of variance procedures examined genotype differences in food preferences; bivariate correlation coefficients examined the relationships among food preferences and the overeating variables; and a regression analysis tested the combined influences of the overeating variables on BMI. DNA was extracted from whole blood for the genotyping, and measures of food preferences and eating behaviours were obtained from well-validated self-report questionnaires.


METHODS
Participants were 300 healthy adult men and women recruited from the community.


RESULTS
All the predicted associations were supported by statistically significant results. In particular, the G/G genotype group of the functional A118G marker of the OPRM1 gene reported higher preferences for sweet and fatty foods compared with the other two groups. Food preferences were also related to all overeating measures, which in turn accounted for a substantial proportion of the variance in BMI.


CONCLUSIONS
Our findings suggest that some of the diversity in the preference for highly palatable foods can be explained by genotypic differences in the regulation of mu opioid receptors. The associations reported in this paper are important from a public-health perspective because of the abuse potential of sweet-fat foods and their strong relationship with obesity.
Kinesiology & Health Sciences, Faculty of Health Sciences, York University, 4700 Keele Street, Toronto, Ontario, Canada. cdavis@yorku.ca
C
C
Davis
C
C
Zai
R D
RD
Levitan
A S
AS
Kaplan
J C
JC
Carter
C
C
Reid-Westoby
C
C
Curtis
K
K
Wight
J L
JL
Kennedy
D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D005247:Feeding Behavior / Q000523:psychology; D005260:Female; D005518:Food Preferences / Q000523:psychology; D020022:Genetic Predisposition to Disease / Q000523:psychology; D005838:Genotype; D006801:Humans; D006963:Hyperphagia / Q000150:complications / Q000235:genetics / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology / Q000235:genetics / Q000523:psychology*; D009293:Opioid-Related Disorders / Q000150:complications / Q000235:genetics / Q000523:psychology*; D020641:Polymorphism, Single Nucleotide; D017450:Receptors, Opioid, mu / Q000235:genetics*; D011795:Surveys and Questionnaires; D055815:Young Adult
C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu