Dietary analysis

Block, G. 1994. Health Habits and History Questionaire Diet history and other risk factors. Dietary Analysis System Packet. Bsathesda, Md. National Cancer Institute. 

There is still much ongoing debate on the validity of the different approaches to perform dietary analysis (single food analysis, duplicate diet analysis, total diet, and total mixed diet analysis) to provide an adequate answer to nutritional questions. The approach followed in this study has proven useful for the assessment of the actual dietary intake of trace metals that may be lost and/or added during the preparation of meals. The measurements done on cooked samples prepared according to the Italian local traditions provides an assessment of the actual concentrations of trace elements uptaken by the population through the diet. 

Dietary intakes of trace elements can be assessed for individual patients or population groups by direct dietary analysis and by taking dietary histories. The estimated intakes can then be compared with the current dietary reference values. 

The ratio of carbon to nitrogen in a sample is used as a measure of the quality of preservation in bone and a means to determine if samples are reliable for the analysis of collagen for radiocarbon dating and dietary analysis using light isotopes. The ratio of C N in living bone is 3.2 a ratio between 2.8 and 3.5 has been suggested as indicative of fossil bone sufficiently well preserved for analysis. 

The techniques used in the assessment of iodine intake are indicative of the reliability of the results, although dietary analysis used in conjunction with biochemical measurements may reduce the margin of error. 

Holt, G.C. (1993) Ecological eating, food ideology and food choice a dietary analysis of the changing British diet with reference to the consumption of organic foods and meat. PhD thesis, December, University of Bradford, Bradford, UK. 

More recently, studies of wine and beer have initiated techniques of statistically vaUd sensory analysis. Scientific studies involving wine continue in these areas, building on past discoveries. Natural phenols as desirable dietary components and monitors of storage and aging reactions are currently active fields. Viticultural research, as well as enological, continues to improve grapes and the wines made from them (11). 

Urea Pharmacokinetics. Pharmacokinetics summarizes the relationships between solute generation, solute removal, and concentration in a patient s blood stream. In the context of hemodialysis, this analysis is most readily appHed to urea, which has, as a consequence, become a surrogate for other uremic toxins in the quantitation of therapy and in attempts to describe its adequacy. In the simplest case, a patient is assumed to have no residual renal function. Urea is generated from the breakdown of dietary protein, accumulates in a single pool equivalent to the patient s fluid volume, and is removed uniformly from that pool during hemodialysis. A mass balance around the patient yields the following differential equation ... 

Lambert, J.B. and Weydert-Homeyer, J.M. 1993 Dietary inferences from element analysis of bone. 

Van Klinken, GJ. 1991 Dating and Dietary Reconstruction by Isotopic Analysis of Amino Acids in Fossil Bone Collagen—with Special Reference to the Caribbean. Ph.D. dissertation. University of Groningen, The Netherlands. 

The examples discussed above suggest useful directions for future research involving trace element analysis of bones. Specifically, the effects of developmental age and other factors (e.g., porosity, mineralization) that may lead to differences in surface area of specimens should be considered. Diage-netic effects should be monitored by analysis of a suite of elements whose abundances are not controlled by dietary abundances (e.g., Mn, Zr, etc.). Finally, although alkaline elements such as Sr and Ba are most likely to reflect the Sr/Ca and Ba/Ca levels of the diet, omnivores such as humans are likely to obtain the majority of these elements from plants rather than from animals. Therefore for accmate diet reconstruction it is necessary to determine the total abundance of Ca as and the Sr/Ca and Ba/Ca ratios of the plant and animal resources that were potential dietary staples. The effects of culinary practices on elemental abundances (Burton and Wright 1995 Katzenberg et al. this volume) must also be evaluated. 

As the name implies, the odor of urine in maple syrup urine disease (brancbed-chain ketonuria) suggests maple symp or burnt sugar. The biochemical defect involves the a-keto acid decarboxylase complex (reaction 2, Figure 30-19). Plasma and urinary levels of leucine, isoleucine, valine, a-keto acids, and a-hydroxy acids (reduced a-keto acids) are elevated. The mechanism of toxicity is unknown. Early diagnosis, especially prior to 1 week of age, employs enzymatic analysis. Prompt replacement of dietary protein by an amino acid mixture that lacks leucine, isoleucine, and valine averts brain damage and early mortality. 

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