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D H Calloway

Publications and source records attributed to D H Calloway.

At least 19 recordsLinked to original sources
PubMed1992

Estimated protein intakes of toddlers: predicted prevalence of inadequate intakes in village populations in Egypt, Kenya, and Mexico.

This paper presents a probability assessment of the adequacy of protein intakes of toddlers (aged 18-30 mo) in study communities in Egypt, Kenya, and Mexico judged in relation to FAO/WHO/UNU estimates of requirements. Effects of supplementing amino acid intakes, or of assuming lower bioavailability for lysine are also considered. In Egypt and Mexico existing protein intakes of toddlers were adequate. In Kenya existing intakes were marginal. Total protein intake was low and often lysine or tryptophan concentration was low. If Kenyan intakes met estimated energy requirements, protein intakes would be adequate. We conclude that protein intake is unlikely to be a primary limiting factor for toddler growth and development, and the benefit to be expected from increasing the intake of limiting amino acids is marginal. Reported associations of animal-source protein and energy with growth, size, and psychologic function of these toddlers are unlikely to be causally attributable to inadequacy of protein intakes.

Amino Acids↗
PubMed1992

Estimated mineral intakes of toddlers: predicted prevalence of inadequacy in village populations in Egypt, Kenya, and Mexico.

Intakes of minerals and factors that might affect their bioavailability were estimated for 255 toddlers aged 18-30 mo living in villages in Egypt, Kenya, and Mexico. Mean intakes over 1 y were compared with international-requirement estimates by using a probability approach. The prevalence of iron intakes likely to be inadequate to prevent anemia was estimated as 35% in Egypt, 13% in Kenya, and 43% in Mexico. The prevalence of zinc intakes likely to be inadequate to meet basal requirements was estimated as 57% and 25% in Kenya and Mexico, respectively, but only 10% in Egypt, where the use of yeast-leavened breads was judged to have improved zinc availability. There was no suggestion that estimated copper or magnesium intakes were inadequate, but calcium intakes in Kenya and Egypt were well below recommended amounts. Studies of factors affecting mineral bioavailability in the diets of these countries' populations could suggest dietary changes that might improve effective mineral intake with minimal cost.

Calcium, Dietary↗
PubMed1989

Menstrual cycle and voluntary food intake.

The relationship of food intake and the human menstrual cycle has not been well quantified. In this study, voluntary energy and sucrose intake of seven women, aged 24-43 y, were evaluated by the weighed-intake method over one entire menstrual cycle. Portable tape recorders facilitated the recording of food intake. Although daily fluctuations of energy intake were large, analysis of variance showed intake during the luteal phase to be significantly greater than during the periovulatory and follicular phases (p less than 0.05). From 95% simultaneous (Bonferoni) confidence intervals, the estimate of difference was 283 kcal greater during the luteal phase than the periovulatory phase; the estimate of difference was 214 kcal greater during the luteal phase than during the follicular phase. No significant differences in energy intake were found among the menstrual, follicular, and periovulatory phases. No significant relationship was found between sucrose intake and the menstrual cycle.

Adult↗
PubMed1986

Effects of energy deprivation on sex hormone patterns in healthy menstruating women.

To determine whether short-term energy deprivation affects sex hormone patterns, six healthy women were studied for two menstrual cycles. Two diets containing recommended levels of all nutrients and differing substantially only with respect to energy content were provided in sequence. During the first cycle, energy intake was 40 +/- 2 kcal/kg body weight, and weight was essentially constant. For the second cycle, energy intake was reduced to 41% of the original intake, averaging 17 +/- 1 kcal/kg initial body weight. During the low-energy diet, weight loss ranged from 3.2 to 6.7 kg. The two leanest women, who also lost the most weight, became anovulatory and amenorrheic in the low-energy period. Within a specific phase of cycle, however, the diet did not affect concentrations of estradiol, progesterone, luteinizing hormone, or follicle-stimulating hormone. Testosterone and androstenedione levels peaked midcycle normally and were decreased with the low-energy diet, while levels of sex hormone-binding globulin increased and those of dehydroepiandrosterone sulfate did not change. These results demonstrate short-term dietary and body composition effects on the menstrual cycle and serum androgens.

Adult↗
PubMed1986

Nutrient intakes of women in NHANES II, emphasizing trace minerals, fiber, and phytate.

Nutrient intakes of 1,066 young women 18 to 24 years of age were estimated using a shortened nutrient data base (the University of California, Berkeley Minilist) containing 235 food items. The dietary data consisted of 24-hour recalls collected during the Second National Health and Nutrition Examination Survey (NHANES II). A cross-reference index, recipe file, and concentration factors were developed to substitute foods on the data base for the 1,267 foods reported by the young women. Estimates of energy, protein, fat, carbohydrate, and iron intakes using the NHANES II nutrient data base and the UCB Minilist were within 3% of one another, and had correlation coefficients above 0.97. Mean +/- S.E. daily intakes of copper, zinc, dietary fiber, and phytate, which are not included in the NHANES II data base, were estimated to be 1.16 +/- 0.02 mg, 8.11 +/- 0.14 mg, 13.2 +/- 0.3 gm, 395 +/- 14 mg, respectively. The values agree closely with other published values for young women's intakes. A shortened nutrient data base can be a valid tool for estimating intakes of populations.

Adolescent↗
PubMed1985

Heart rate and energy expenditure of pregnant and lactating women.

Data on heart rate and oxygen consumption of 21 mature pregnant women, and of 16 of them postpartum, were examined for evidence of the suitability of heart rate as an index of energy expenditure during pregnancy. Energy expenditure, measured by indirect calorimetry, and heart rate were recorded with subjects at rest (lying, sitting, and standing) and working (on a treadmill and cycle ergometer) at three different levels. Energy expenditure (EE) and heart rate (HR) were highly correlated during the second half of gestation and postpartum. Both EE and HR were affected by pregnancy state, but the relationship between HR and EE was not changed. Slopes of regression of two linear components of EE/HR relationship were 0.01-0.02 for resting, and 0.05-0.06 for working measures. The slopes under resting and working conditions are significantly different from zero, and from each other. Prediction of EE from HR is unreliable in the range 80-120 beats/min where resting and working HRs overlap.

Adult↗
PubMed1984

Physical activity improves protein utilization in young men.

Protein utilization in young men under circumstances of one or two periods of work and both adequate and surfeit energy intake was determined by nitrogen balance; protein intake was constant at the FAO/WHO (1973) safe level (0.57 g/kg body-weight). Physical activity affected protein utilization negatively by increasing sweat and faecal N losses, and positively by supporting increased energy intake. Efficiency with which surfeit energy improved N utilization (mg N retained/added kJ) was greater under circumstances of increased activity. Changes in body composition as determined by total body potassium and hydrostatic weighing supported the N retention values.

Adult↗
PubMed1984

Effects of marginally negative energy balance on insulin binding to erythrocytes of normal men.

Six healthy male volunteers were confined to a metabolic unit for 105 days. Energy intake (EI) and energy expenditure (EE) were varied in order to achieve either a marginally negative (-15%) or an equilibrated energy balance (EB), in different metabolic periods (MP) as follows: MP I: EE = 1, EI = 1, EB = 0; MP II: EE = 1, EI = 0.85, EB = -15%; MP III: EE = 0.85, EI = 0.85, EB = 0; MP IV: EE = 0.85, EI = 0.70, EB = -15%; MP VI: EE = 1.15, EI = 1.15, EB = 0; MP VII: EE = 1.15, EI = 1, EB = -15%. An egg protein formula diet was fed throughout the study. The amount given in MP I was sufficient to maintain body weight constant. Assigned physical activity consisted of regulated walking and cycling. During MP I, this physical activity accounted for 15% of the energy intake. Serum insulin, insulin binding to erythrocytes and body fat content were determined at the end of each MP. No significant changes were found in serum insulin level throughout the study, but specific insulin binding did change significantly. Binding increased with increased physical activity by 23% at the end of MP VI and an additional 35% at the end of MP VII. The maximum percentage of insulin binding to erythrocytes correlated inversely with the percentage of body fat in each MP. These data suggest that insulin binding to erythrocytes, in normal men, is sensitive to a small change in energy balance, and especially to physical activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Hormonal changes in normal men under marginally negative energy balance.

Six men were confined to a metabolic unit for 105 days. Their assigned work and energy intake were varied throughout six metabolic periods in order to create either a marginally negative (-15%) or an equilibrated energy balance. They were fed a defined diet providing a constant amount of protein. At each metabolic period, T4, T3, reverse T3(rT3), free T3, free reverse T3, thyroid-stimulating hormone, cortisol, cortisol-binding globulin, testosterone, and testosterone/estradiol-binding globulin were measured. Free urinary cortisol was measured daily. Results show that serum thyroid hormones are sensitive to marginal changes in energy intake, expenditure, and balance. The ratio T4/T3 appears to be more sensitive to the balance itself, with the ratio T3/rT3 being more sensitive to the intake and expenditure level at which this balance is established. Regulations of T3 and rT3 production are probably distinct. Urinary cortisol did not show any variation that could be related to the energy balance. However, daily urinary cortisol was correlated to daily urinary nitrogen excretion. No change in serum testosterone was found.

Adult↗
PubMed1984

Nitrogen balance in men with adequate and deficient energy intake at three levels of work.

Two studies were conducted to investigate the effects of mild exercise on nitrogen balance in men given diets supplying adequate or slightly limiting energy. In experiment A the diet supplied 91 mg N/kg body weight (0.57 g protein/kg, the FAO/WHO safe level of intake) as egg white; in experiment B the same source was used to provide the 1980 NRC-RDA for adult males, 128 mg N/kg body weight (0.8 g protein/kg). By adjusting energy intake and activity, periods of energy equilibrium and negative energy balance (-15%) were achieved at three levels of activity (X for exercise): no programmed work (0.85X), 1 hour of treadmill walking (1.0X) and 1 hour each of treadmill and cycle ergometry (1.15X). "True" nitrogen balance (TNbal) was more positive or less negative during periods of energy equilibrium as compared to those of energy deficit. This effect of energy balance on TNbal increased with physical activity. At the lower protein intake the mean difference in TNbal between the period of energy equilibrium and that of energy deficit at 1.0X was 0.19 g N/day (nonsignificant difference) and 0.54 g N/day at 1.15X. When protein intake was increased, the difference in TNbal between periods of equilibrium and deficit was significant at all levels of activity: 0.65 g N/day at 0.85X, 0.93 g N/day at 1.0X and 1.09 g N/day at 1.15X. Physical activity was anabolic when energy balance was maintained. In experiment A the addition of 1 hour of exercise (1.0X to 1.15X) spared 2.5 mg N/kg body weight; reducing activity by 1 hour (1.0X to 0.85X) cost 1.4 mg N/kg body weight. In experiment B, TNbal was more positive with increased activity (by 5.9 mg N/kg body weight) and more negative (by 11.5 mg N/kg body weight) when the men were sedentary. During periods of energy deficit, the anabolic effect of activity was also present, although less markedly. When activity increased from 1 to 2 hours in experiment A, TNbal improved by 2.1 mg N/kg body weight and in experiment B, by 3.5 mg N/kg body weight. Thus, circumstances of negative energy balance with adequate protein intake are better tolerated when the energy deficit is generated by physical activity than when it derives from reduced intake; the picture when protein intake is marginal requires further investigation.

Adult↗
PubMed1984

21st Lenna Frances Cooper memorial lecture: nutrition research by and about women.

Physiologists, chemists, and a few physicians, virtually all men, carried out the early research in human nutrition. Nutrition emerged as a "woman's field" of study and practice during a period when women's attempts to enter traditionally male-dominated fields of science were being resisted and frustrated. Nutrition benefited as a result, because it was given the attention of outstanding women scholars denied opportunities in their own fields. Women were the principal investigators of the nutrition concerns of women and children, for reasons of access and gentility . Analysis of historical and contemporary contributions by and about women suggests a gender difference between investigators' concerns: Men explore problems; women study needs.

Female↗
PubMed1983

Food intake measurement: problems and approaches.

Sources of variance in dietary intake records were measured and compared. Eighteen graduate students recorded self-selected food intakes during a 30-day study. Subjects were divided into two groups and on alternating 5 consecutive day periods, one group weighted all food consumed and recorded it on tape recorders while the other group recorded estimated intake in small notebooks. An average of two, 24-h dietary recalls was also obtained from each subject and compared to previously estimated intake. The major contributions to total variance were within subject and between subject variance. There was no difference in the mean protein and energy intake recorded by weighing when compared to that recorded in household measures, but there was less variability in the records obtained by weighting intake. The 95% confidence limits were calculated both for the group's and an individual's intake for each method, these demonstrated that 1-day dietary record gave a reasonable estimate (within 15%) of the usual intake of the group. However, the 1-day record, regardless of which method used, gave a meaningless estimate of an individual's usual diet. The protein/energy ratios and the coefficient of interindividual variation are also reported.

Adult↗
PubMed1982

Menstrual cycle and basal metabolic rate in women.

Basal metabolic rate, resting metabolic rate (RMR), and energy cost of selected activities were measured in six healthy young women who were participating in a study of protein requirements. The women were confined to a metabolic unit for 92 days during which they consumed a defined formula diet. The basal metabolic rate of the women was 20.7 +/- 2.6 kcal/kg body weight/day and the caloric requirement for maintenance of weight was 38.7 kcal/kg body weight/day. Basal metabolic rate varied significantly with the menstrual cycle. Basal metabolic rate decreased at menstruation and fell to its lowest point approximately 1 wk before ovulation subsequently rising until the beginning of the next menstrual period. RMR was 0.99 +/- 0.16 kcal/kg/h. The energy expenditure while sitting was 1.06 times RMR, while walking it was 2.81 times RMR, and while performing treadmill exercise it was 3.47 times RMR.

Basal Metabolism↗
PubMed1982

Menstrual cycle and protein requirements of women.

A nitrogen balance study was done to determine the protein requirement of healthy young women and to evaluate the impact of the menstrual cycle on nitrogen utilization. Six healthy young women were fed a defined formula diet with progressively decreasing levels of egg white protein: 4 mg nitrogen/basal kcal for 42 days, 3 mg nitrogen/basal kcal for 28 days and 2.5 mg nitrogen/basal kcal for 22 days. Dietary energy was fixed at about 38 kcal/kg body weight and exercise was standardized. Excreta, menstrual fluids, and integumentary losses were collected. A statistically significant (P less than .001) biphasic cycle in urinary nitrogen excretion was found in every subject. Linear regression analysis predicted nitrogen requirement to be 73 +/- 20 mg nitrogen/kg body weight. When expressed per kilogram of body weight, there appears to be no significant difference in protein requirement between women and men. The urinary nitrogen cycle, however, was found to be unique to women, implying a hormonal regulation of nitrogen utilization. The failure to account for this cycle in women could lead to erroneous estimates of nitrogen requirement or large coefficients of variation.

Adult↗
PubMed1982

Proteins, vitamin A, carotene, folacin, ferritin and zinc in Navajo maternal and cord blood.

Blood samples were obtained from 28 Navajo women at delivery and cord blood samples were collected from their healthy, full-term infants. The concentrations of retinol, folacin, ferritin and zinc in the cord blood fell in the normal range even though some mothers had blood levels suggesting a deficiency. Levels of maternal and cord blood retinol-binding protein were positively correlated. Although marginal and deficient levels of folacin in maternal blood did not result in significantly lower cord blood levels, the strong association indicated a dependence of fetal level upon maternal supply. Birth weight and the developmental indices were not related to any of the maternal or fetal nutrient levels.

Adolescent↗
PubMed1981

Evaluation of lactational performance of Navajo women.

The effect of suboptimal maternal nutrition on lactational performance of 23 Navajo women was studied in terms of milk volume, milk composition, and infant growth. The mean milk volume produced by 10 Navajo women was 634 +/- 113 mg/24 h after approximately 1 month of lactation. The content of protein, lactose, and lipid were within normal limits. Retinol and carotene content were 32.9 +/- 15.7 and 19.7 +/- 6.3 microgram/dl, respectively. Milk folacin averaged 56.4 +/- 23.9 mg/ml. The mean contents of zinc, iron, and copper were 2.8 +/- 1.1, 0.8 +/- 0.6, and 0.3 +/- 0.2 mg/l, respectively. Despite evidence of suboptimal nutriture among these Navajo women, lactational performance was adequate in terms of infant growth, milk volume, and milk composition with the exception of vitamin A which was lower than normal.

Adolescent↗