Susceptibility of diabetes is determined by inherited differences in DNA, but environmental factors such as diet, weight, age, and physical activity seem to be triggering the onset of the disease. Genetic make-up, in addition to the environment with which the genes are exposed to, is influencing the behaviour of consumers with regard to the food choices they make. Addiction to substance abuse is partially determined by genes, which predispose individuals to have addictive personalities; however the stimuli with which an addiction develops is dependent on the environment.