Both fresh and processed foods make up vital parts of the food supply. Processed food contributes to both food security (ensuring that sufficient food is available) and nutrition security (ensuring that food quality meets human nutrient needs). This ASN scientific statement focuses on one aspect of processed foods: their nutritional impacts. Specifically, this scientific statement 1) provides an introduction to how processed foods contribute to the health of populations, 2) analyzes the contribution of processed foods to "nutrients to encourage" and "constituents to limit" in the American diet as recommended by the Dietary Guidelines for Americans, 3) identifies the responsibilities of various stakeholders in improving the American diet, and 4) reviews emerging technologies and the research needed for a better understanding of the role of processed foods in a healthy diet. Analyses of the NHANES 2003-2008 show that processed foods provide both nutrients to encourage and constituents to limit as specified in the 2010 Dietary Guidelines for Americans. Of the nutrients to encourage, processed foods contributed 55% of dietary fiber, 48% of calcium, 43% of potassium, 34% of vitamin D, 64% of iron, 65% of folate, and 46% of vitamin B-12. Of the constituents to limit, processed foods contributed 57% of energy, 52% of saturated fat, 75% of added sugars, and 57% of sodium. Diets are more likely to meet food guidance recommendations if nutrient-dense foods, either processed or not, are selected. Nutrition and food science professionals, the food industry, and other stakeholders can help to improve the diets of Americans by providing a nutritious food supply that is safe, enjoyable, affordable, and sustainable by communicating effectively and accurately with each other and by working together to improve the overall knowledge of consumers.

Studies in vitro and with intact chicks support the view that liver is the major site of lipid biosynthesis in the chicken. Adipose tissue is relatively unimportant as a site of fatty acid biosynthesis in this species although it does have the ability to esterify fatty acids to triglycerides. The available evidence, therefore, suggests that in the chicken, and presumably other avian species, fatty acids are synthesized in liver and are transported as triglycerides in the plasma low-density lipoproteins to the adipose tissue for storage. Fasting, even for short periods of time, markedly depresses the capacity for hepatic lipogenesis in the chick. Food restriction for 2 hr. depresses hepatic lipogenesis by about 90% and refeeding for 1 hr./or/the intravenous administration of glucose or fructose restores the lipogenic capacity. Feeding diets high in fat or protein cannot be adequately explained on the basis of the reduction of dietary carbohydrate which accompanies increased dietary protein or fat levels. Dietary fat and protein appear to exert their effects on hepatic lipid synthesis by different mechanisms. The depression in hepatic fatty acid synthesis brought about by fasting or fat-feeding is accompanied, and probably preceded, by an increased plasma free fatty acid level. Under these conditions hepatic fatty-acyl CoA levels increase while free CoA levels are reduced. Long-chain acyl CoA derivatives are capable of inhibiting acetyl CoA carboxylase activity as well as citrate transport. The reduced availability of free CoA may limit the citrate cleavage reaction. Dietary alterations influence the hepatic lactate-pyruvate ratio of chicks, however the changes observed are not always consistent with the changes observed in rat liver. Chicks fed high-protein diets have a decreased hepatic lactate/pyruvate ratio indicative of a more oxidized cytoplasmic environment. This change in redox state may be associated with control of fatty acid synthesis in chicks fed high-protein diets. Thyroxine and glucagon affect hepatic fatty acid synthesis in the chick, however insulin appears to play a lesser role.

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Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene-nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient -genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.

SALATRIM is a reduced-calorie fat substitute composed of structured triacylglycerols. These structured triacylglycerols are composed of long-chain fatty acids (predominantly stearic) and short-chain aliphatic acids (acetic, propionic, and/or butyric). It has been demonstrated in rat studies and in a clinical study that SALATRIM with various combinations of these aliphatic acid and fatty acid side chains delivers fewer calories per gram than conventional triacylglycerols such as corn oil. The reduced calories are accounted for by the lower caloric value of the short-chain aliphatic acids and limited absorption of the stearic acid which is freed by enzymatic hydrolysis in the gastrointestinal tract. In caloric availability studies with rats SALATRIM was found to deliver between 4.5 and 6.0 keal/g. In the human clinical study between 27.6 and 36.5% of the stearic acid in SALATRIM was shown to be absorbed, resulting in an apparent caloric availability of between 4.7 and 5.1 keal/g. Although subjects consuming SALATRIM exhibited an increased excretion of fecal fat and stearic acid, they did not excrete higher levels of calcium, magnesium, or zinc. These results show that SALATRIM exhibits similar caloric reduction in both rats and humans.

Coho salmon (Oncorhynchus kisutch), 8 to 18 months of age, were maintained in culture tanks and were fed three semipurified diets. The diets contained 40% of energy from protein and 11.5%, 23%, or 46% of energy from lipid. The body weight gain and food conversion factors were similar among groups of fish fed the diets in each of the three experiments. Wet weight of mesenteric adipose tissue increased with increased amount of lipid in the diet; however, epaxial muscle lipid content was not influenced by the lipid content of the diet. Several hepatic and adipose tissue lipogenic enzymes (fatty acid synthetase, citrate cleavage enzyme, malic enzyme, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and NADP-isocitrate dehydrogenase) were assayed. These lipogenic enzymes exhibited high activities in liver and relatively low concentration in adipose tissue of the fish. The activities of all the hepatic lipogenic enzymes assayed, except for NADP-isocitrate dehydrogenase, were depressed as the level of lipid in the diet was increased; however, the activities of these enzymes in mesenteric adipose tissue were not influenced by the diets fed. The results of this study indicate that dietary lipid depresses hepatic lipogenic enzyme activities and that the liver may be a more important site for fatty acid synthesis than is adipose tissue in coho salmon.

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