A meta-analysis of the relationship between brain dopamine receptors and obesity: a matter of changes in behavior rather than food addiction?

Benton, D. and Young, H.A. (2016) International Journal of Obesity, 40, S12–S21; doi:10.1038/ijo.2016.9

OBJECTIVE: To examine the role of dopamine D2 receptors (DD2R) in obesity, through associations between BMI and the Taq1A polymorphism. The A1 allele is associated with a 30–40% lower number of DD2R, and is a risk factor for drug addiction.

DESIGN: A systematic review and meta-analysis of 33 studies.

SETTING: Various

PARTICIPANTS: Various

MAIN OUTCOME MEASURES: N/A

RESULTS: In children and adolescents, no study reported a difference in BMI between those with and without the A1 allele. This was also observed in the majority of studies in adults who were either a healthy weight or overweight, as well as those who were obese. A meta-analysis of the studies where BMI was available showed no difference in BMI depending on the presence of the allele. This remained true when considering those with a BMI > 30kg/m2 and those with a BMI > 40kg/m2. In analysis of the frequency of occurrence of the A1 allele in those with a BMI < 25kg/m2 compared with those who were obese, overall, there was a greater chance of having the A1 allele if in the obese group (Z = 2.005, P<0.045, OR = 1.446, 95% CI 1.008–2.073). However, when the studies of children and adolescents were considered separately, there was no significant difference.

CONCLUSIONS: These analyses do not support a reward deficiency theory of food addiction.

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