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Biomedical subjects

C E Bodwell

Publications and source records attributed to C E Bodwell.

At least 37 records · Page 2Linked to original sources

A new approach for the estimation of body composition: infrared interactance.

A new method for the estimation of body composition in humans, called infrared interactance, is discussed. Infrared interactance is based on the principles of light absorption, reflection, and near-infrared spectroscopy. Body composition (percentage fat) was estimated in 53 adults (23 to 65 yr of age) by infrared interactance and compared to results from deuterium oxide dilution (r = 0.94), skinfold (r = 0.90), and ultrasound (r = 0.89) measurements. The method is safe, noninvasive, rapid, easy to use, and may prove useful to predict percentage body fat, especially in the obese.

Adipose Tissue↗

Calorie and protein intake and balance of men and women consuming self-selected diets.

The calorie and protein intakes of 16 women and 13 men consuming self-selected diets over a 1-yr period were determined. During four 7-day balance periods, corresponding to the four seasons of the year, duplicates of diets consumed and urine and feces excreted were collected for analysis and calculations of available energy and nitrogen balance. During the four balance periods, the food intakes and thus the calorie and protein intake of the subjects decreased as documented by 7-day food records immediately before and after the balance periods. This unexpected decrease in food consumption made the nitrogen (N) balance results difficult to interpret. The energy digestibility of these diets ranged from 87 to 98% (mean +/- SD, 93.7 +/- 2.3). The nitrogen digestibility of the diets ranged from 80 to 96% (mean +/- SD, 88.6 +/- 3.4). The analyzed calorie values (heats of combustion) of the diet composites were approximately the same as calorie values of these diets calculated from diet records using food tables. This is surprising since calorie values in food tables are available energies which have been corrected by a coefficient of availability.

Adult↗

Iron intake and status of men and women consuming self-selected diets.

Iron intakes and iron status (serum ferritin and iron balance) were determined in 16 women and 13 men consuming self-selected diets over a 1-yr period. Iron balance was determined during four 7-day balance periods corresponding to the four seasons of the year. The seasonal variation in iron intake and serum ferritin and the correlation among iron intake, iron balance, and serum ferritin was examined. No seasonal variation was found in iron intake or serum ferritin. No direct correlation could be found between iron status (ferritin levels and iron balance) and iron intake. However, the men who met or exceeded their recommended dietary allowance for iron intake had ferritin levels in a range indicative of adequate iron status. None of the women met their recommended dietary allowance and their ferritin levels indicated marginal iron stores.

Adult↗

A face mask for estimation of whole body leucine turnover in unanesthetized beagle dogs.

As part of a long-term study of protein and energy metabolism in Beagle dogs, a latex face mask was developed to facilitate respiratory gas collection. The mask described here is easily assembled using readily available materials and meets the following criteria: small dead air space, lightweight, readily acceptable by conscious dogs over a prolonged period of time, leakproof , and inexpensive. The mask has been successfully used with L-[1-13C] leucine to measure 13CO2 excretion rates in studies of leucine metabolism.

Animals↗

Heats of combustion of chemically different lipids.

The caloric content of foods listed in food composition tables, such as the USDA Agriculture Handbook No. 8, is calculated by multiplying the gram amount of the protein, fat, and carbohydrate in the food by specific caloric factors derived around the turn of the century by Atwater and co-workers. To evaluate the accuracy of these specific caloric factors, we determined the heats of combustion of vegetable oils as purchased; of lipids extracted from red meats, chicken, fish, egg yolk, and cereal grains; and of the residue (protein) left after lipid extraction of the meats. These heats of combustion were converted to available energy values by the method of Atwater . The specific caloric factors used to calculate the caloric content of foods in Agriculture Handbook No. 8 and other tables of food composition may exaggerate the calories contributed by the lipids in some foods. When the food lipid was mainly triglyceride, the available energy values calculated in this study were within 2% of the specific factors used in Agriculture Handbook No. 8. However, when the food lipid had a high content of phospholipid, our calculated available energy values were lower than the specific factors used currently. The energy content of the fat-free residue (protein) of meat, poultry, and fish was also less than that currently used for those foods in food composition tables.

Animals↗

Protein digestibility of the same protein preparations by human and rat assays and by in vitro enzymic digestion methods.

The apparent and true digestibilities of the same preparations of six proteins (spray dried whole egg, cottage cheese, canned tuna, peanut flour, soy isolate, and wheat gluten) were estimated in four to five men and in rats and compared to estimates of digestibility from three different in vitro enzymic digestion procedures. For all six proteins, the correlation coefficient was 0.46 between true digestibility in humans and in rats; with values for tuna excluded, r = 0.96. With all six proteins, none of the in vitro values was significantly correlated with values from humans or rats. However, with either the three animal proteins alone or the three plant proteins alone, correlations were high (r greater than 0.90) between one or more of the in vitro estimates and the observed true or apparent human and rat digestibilities. The differences in the relationship between enzymic digestion estimates and the human digestibility estimates for plant or animal proteins suggest that for accurate prediction of protein digestibility in humans by these enzymic methods, different equations would have to be used for plant and animal proteins. For protein sources containing both plant and animal protein, use of the in vitro enzymic procedures would give only an approximate estimate of digestibility in humans.

Adult↗

Obligatory urinary and fecal nitrogen losses in young women, older men, and young men and the factorial estimation of adult human protein requirements.

Obligatory urinary and fecal nitrogen losses and urinary urea nitrogen and creatinine excretion levels were determined in 11 young women (four of whom used oral contraceptives), eight older men, and five young men. Values for obligatory nitrogen losses in the young women who did not use oral contraceptives were similar to those observed previously in young women and lower than those reported for young men. Our values for older men were lower than previously reported values for obligatory losses observed in young and elderly men, but similar to previously reported values for young women and to values for our women who did not use oral contraceptives. The four oral contraceptive users had significantly higher levels of total urinary and fecal obligatory nitrogen losses than the nonusers in our study. When values from our study and values from other recent studies are considered, variations in obligatory nitrogen losses appear to be larger among individuals within an age-sex group than the observed differences between groups. When the intakes of protein recommended as safe by the Food aculated from obligatory nitrogen losses per se, the recommended levels appear to be only marginally adequate.

Adult↗