The purpose of the Annual Review of Nutrition, as with the 27 other subject areas now covered by Annual Reviews, is to offer “comprehensive, timely collections of critical reviews written by leading scientists.” Given the broad span of nutrition, which is based on several disciplines, there is a significant overlap with topics addressed in volumes intended to represent other subject areas. It is for this reason that we call your attention each year to “Some Related Articles in Other Annual Reviews” on page ix. In the digestion, absorption, and utilization of nutrients, an organism involves numerous processes that we conventionally ascribe to biochemistry and molecular biology, cell biology, physiology, and the like. With humans there are obvious extensions toward medicine and public health. Those Annual Reviews volumes that cover findings in these disciplines contiguous to nutrition enhance the contemporary knowledge base and provide examples of potential interest to nutritionists.

The current volume begins with a prefatory chapter by Khan & Bowman that discusses obesity—the most common nutrition disorder in the United States—and its global impact on public health systems. The use of recombinant adenoviruses as tools for metabolic engineering is reviewed by Antinozzi et al. The use of transgenic models for growth hormone action reviewed by Kopchick et al and the discussion by Rosen et al of how milk protein gene expression is regulated also reflect the applications of modern biologic methodologies brought to bear in the nutrition arena. Grundy discusses the dietary balance of fat-to-carbohydrate that may be preferred for our health. The regulation of glucose production by liver is considered by Nordlie et al, and Jump & Clarke review how dietary fat regulates gene expression. Other chapters that are focused on lipids attend to their genetic alteration in plants as reviewed by Broun et al, mammalian low-density lipoprotein receptors updated by Hussain et al, regulation of fatty acid oxidation in skeletal muscle by Rasmussen & Wolfe, and nonoxidative modifications of lipoproteins reviewed by Tabas. With continuing interest in homocysteine, long known to be reflective of the status of certain B vitamins and more recently considered as possibly related to heart disease risk, Selhub has reviewed this subject. The receptor-mediated endocytosis of (continued ) cobalamin is reviewed by Seetharam, and carrier-mediated transport of folate in mammalian cells is updated by Sirotnak & Tolner. Progress made in understanding vitamin E transport is summarized by Traber & Arai. We are informed of more recent work on inorganic micronutrients with chapters on dietary selenium by Stadtman and colleagues and on use of chromium as a supplement by Lukaski. Policies and programs for control of micronutrient malnutrition are considered by Underwood & Smitasiri. Issues that bear on clinical considerations include a review by Lipkin et al on dietary factors in colorectal cancer and areview by Baik & Russell on B12 deficiency in the elderly. More broadly, we are informed by Baranowski et al on psychosocial correlates of dietary intake and by Birch on development of food preferences. Finally, under the category of comparative nutrition, Nagy et al review work elucidating some aspects of the energetics of certain free-ranging animals.

As stated before, credit for quality and content goes to the chapter contributors, who are selected by the Editorial Committee. We continue to welcome suggestions for authors and topics to be considered annually by the Committee. Our "anchor" to Annual Reviews is now Lisa Dean, the Production Editor. We continue to appreciate the leadership of Dr. Sam Gubins as President of Annual Reviews.

In conclusion, we would draw the attention of our readers to the fact that access to the Annual Reviews is augmented by the Internet: Full texts of all Annual Reviews are available on-line; literature citations to recently published articles in the Proceedings of the National Academy of Science (USA), the Journal of Biological Chemistry, and Science are linked to their full text; the citations are also linked to Medline; and there are materials on the Annual Review of Nutrition web site that supplement what appears in the printed Volumes 18 and 19. It is likely that in future there will be greater use of the web for materials such as videos and animations.

Donald B. McCormick, Editor