Background: The modern environment is ubiquitously 'obesogenic', yet people vary enormously in weight. One factor contributing to weight variation could be genetically determined differences in appetite that modulate susceptibility to the environment. We assessed the relative contribution of genes and environment for two aspects of appetite that have been implicated in obesity.
Methods: Parents of a population-based sample of 8- to 11-year-old twins (n=5435 pairs) completed validated, questionnaire measures of responsiveness to satiety and responsiveness to food cues for both children.
Results: Quantitative genetic model fitting gave estimates of 63% (95% confidence interval: 39-81%) for the heritability of satiety responsiveness and 75% (52-85%) for food cue responsiveness. Shared and non-shared environmental influences were 21% (0-51%) and 16% (10-21%) for satiety responsiveness, and 10% (0-38%) and 15% (10-18%) for food cue responsiveness, respectively.
Conclusions: The high heritability of appetitive traits that are known to be related to weight suggests that genetic vulnerability to weight gain could operate through behavioural as well as metabolic pathways. Intervention strategies aimed at improving satiety responsiveness and reducing food cue responsiveness in high-risk individuals could help in preventing the development of obesity.