Eating behavior in the Old Order Amish: heritability analysis and a genome-wide linkage analysis

Abstract

Eating behavior and thus dietary intake affect the development of obesity-related diseases such as diabetes, hypertension, and hyperlipidemia. We investigated the genetic underpinnings of eating behavior. We administered a standardized eating behavior inventory to 624 adults from 28 families participating in the Amish Family Diabetes Study. Three quantifiable components of eating behavior were measured: restraint, disinhibition, and hunger. Associations between eating behavior scores and physical characteristics were evaluated. Heritability analysis and a genome-wide multipoint linkage analysis were performed. Eating behavior scores were associated with obesity and obesity-related phenotypes. Heritability estimates were 0.28 +/- 0.09 for restraint, 0.40 +/- 0.10 for disinhibition, and 0.23 +/- 0.09 for hunger (P < 0.001). The linkage analysis showed 4 regions of suggestive linkage. We observed suggestive evidence for linkage of restraint scores to 2 chromosomal regions, near markers D3S1304 [LOD (log of odds) = 2.5, P = 0.0003] and D6S276 (LOD = 2.3, P = 0.0006). We previously reported that D3S1304 is linked to a locus influencing percentage body fat in this same population (LOD = 1.6), suggesting that this behavioral phenotype may be secondary to obesity. The maximum LOD scores for disinhibition were 1.6 (P = 0.003) near marker D7S657 and 1.4 (P = 0.005) near marker D16S752. The maximum LOD score for hunger was 1.4 (P = 0.005) near marker D3S1278. Significant familial effects on eating behavior and suggestive genetic linkage were found in Amish adults.