Palatability and intake relationships in free-living humans: the influence of heredity

The heritability of the before and after meal self-ratings of palatability and their relationship to food intake was investigated with 86 identical and 78 fraternal same-sex and 51 fraternal mixed gender adult twin pairs who were paid to maintain 7-day food intake diaries. From the diary reports, the total and meal intakes of food energy and the amounts of the macronutrients ingested were estimated. Participants rated the meals for palatability on a 7-point (Bad - Good) scale both before and after eating. Linear structural modeling was applied to investigate the nature and degree of genetic and environmental influences and revealed significant genetic influences on subjective palatability both before and after the meals. In addition, the relationship between palatability and intake was influenced by the genes. Significant dominance genetic effects were found for the change in meal size between low-moderate and high palatability meals, indicating that palatability and it's relationship with intake are to some extent heritable. This suggests that the level of subjective experience and the individuals responses to them are influenced by the genes and become part of the total package of genetically determined physiological, socio/cultural, and psychological processes that regulate energy balance.