Variants of dopamine system genes such as the DRD4 and the SLC6A3 genes may be involved in food intake regulation because the dopaminergic system influences food reward. We investigated an association of polymorphisms in the DRD4 (exon 3 VNTR) and SLC6A3 (3’UTR VNTR, rs2550948, rs2652511 and rs1048953) genes with food intake and nutritional status in children. This prospective cohort study recruited 359 children at birth. Dietary data and nutritional status were collected at 1year, 3-4 years, and 7-8 years of age. The polymorphisms were analyzed using polymerase chain reaction based techniques. Food intake and nutritional status were compared among the different SNP genotypes. In the first year of life, DRD4.7R- children showed higher BMI Z-scores (P=0.019) than the DRD4.7R+ cohort. At 3 to 4years old, DRD4.7R- and SLC6A3.10R/10R children showed a higher intake of palatable foods (P=0.024) and a higher waist circumference (P=0.017). The rs1048953 SLC6A3 polymorphism was associated with average daily energy intake (P=0.003) at 3 to 4years and with a waist-to-height ratio of children at 7 to 8years (P=0.041). Carriers of high dopamine activity alleles of the VNTRs studied in DRD4 and SLC6A3 genes and carriers of T/T genotype of the variant rs1048953 SLC6A3 can present an increased risk for obesity related to overeating because high dopamine activity can increase the perceived incentive value of food reward.
