đa hình trao một nguy cơ gia tăng bệnh tiểu đường, nhưng nguy cơ sẽ được khuếch đại bởi chế độ ăn uống, béo phì nghèo, và thiếu tập thể dục. Vì vậy, các gen make-up có thể ảnh hưởng như thế nào các sinh vật sẽ phản ứng với môi trường ngay lập tức. Tương tự, như chúng ta sẽ thấy, | 66 Fetal choices polymorphisms confer an increased risk of diabetes but the risk will be amplified by obesity poor diet and lack of exercise. So the genomic make-up can influence how the organism will respond to the immediate environment. Equally as we shall see the consequences of predictive responses are affected by the concurrent postnatal environment and in turn the way in which an adult responds to the environment is conditioned by developmental adaptations. Let us use a hypothetical example we know that individuals with obesity of the trunk especially within the abdomen as opposed to the hips and thighs are morelikelyto get Type 2 or adult-onset non-insulindependent may be more so in individuals with a certain genetic make-up affecting genes responsible for insulin sensitivity. But truncal obesity is related to bad diet and poor exercise habits. This is a good example of a gene-environment interaction that results in an increased risk of disease. But what if the appetite and metabolic responses to exercise were established early in life or even before birth What if the tendency to lay down truncal fat was determined by developmental events that set out a map of how body fat would be deposited not for fetal advantage but for a predicted postnatal advantage In this case is the important gene-environment interaction the one happening in adulthood or the one that happened in utero If the organism had not developed truncal fat in the first place then the risk of diabetes occurring as a result of adult dietary and exercise habits would have been much less. From the disease prevention point ofview it is likely to be the first event that occurred namely the phenotypic change in utero. It should be obvious that if this theoretical scenario is correct then measures aimed at modification of adult lifestyle in order to reduce the risk of diabetes would in the long-term have less effect than a strategy aimed at optimising fetal development so that the right
