Nutrients should be viewed as the earliest of the hormone signals whic
h allowed an organism to respond to changes in its nutrient environmen
t. Defining nutrient function at the nuclear level will permit us to u
nderstand how our dietary environment is related to the development of
nutritionally related pathophysiologies such as diabetes, heart disea
se, and cancer. Moreover, through the application of molecular techniq
ues, we will begin to understand how specific nutrients govern the dev
elopmental pattern of specific organs such as the kidney In this revie
w, the fatty acid synthase gene is employed as a model to demonstrate
how one sequentially approaches questions pertaining to the regulation
of gene expression by a nutrient, and the article presents a nuclear
explanation for how dietary polyunsaturated fats decrease blood trigly
cerides. More importantly, studies of this nature provide a basis for
screening genetically susceptible populations and information that wil
l allow the nutritionists of the 21st century to customize a diet for
patients at risk.