Appetite is a heritable phenotype associated with adiposity

Background: The high heritability of adiposity combined with its shifting distribution over time suggests that genetic and environmental influences interact in the etiology of adiposity. Purpose: The purpose of this study is to examine evidence that genetically determined differences in appetite underlie variation in susceptibility to obesogenic environments. Methods: Summary of a program of published research. Results: Recent behavioral and psychometric studies demonstrate that appetitive characteristics such as responsiveness to internal satiety signals and external food cues not only differentiate obese and normal-weight groups, but are quantitatively associated with weight. Twin analyses show that variation in these appetitive traits is highly heritable. Sensitivity to internal satiety cues is linked with the FTO gene and mediates the association between FTO and weight. Conclusions: These results indicate that sensitivity to internal and external appetitive signals are heritable phenotypes that increase the risk of overeating in "obesogenic" environments. A behavioral susceptibility model helps to explain how weight is both highly heritable and highly responsive to environmental characteristics.