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Biomedical subjects

G B Spurr

Publications and source records attributed to G B Spurr.

At least 19 recordsLinked to original sources
PubMed2002

Energy intake and expenditure of free-living, lactating Colombian women in an urban setting.

OBJECTIVES: To examine the components of energy balance during lactation in a population of economically disadvantaged women in an urban developing country setting in order to better understand the metabolic response to lactation. DESIGN: Cross-sectional comparison of lactating (LACT) and non-pregnant non-lactating (NPNL) women. Body size and composition were assessed via anthropometry, energy intake was measured using estimated diet records and energy expenditure using indirect calorimetry and the Flex-Heart Rate method. SETTING: Low-income neighborhoods of Cali, Colombia. SUBJECTS: Lactating women (n=15) studied at 2.4+/-0.8, 5.5+/-0.8 and 8.9+/-1.2 months postpartum, and NPNL women (n=48) studied in three measurement rounds at 0, 3.5+/-0.6 and 7.1+/-1.0 months. RESULTS: There were no significant differences between LACT and NPNL women in anthropometric dimensions, but LACT women showed decreases in waist-hip ratio, lean body mass and increases in mid-arm circumference and percentage body fat with time. Energy intake was higher in LACT women (P=0.04), but there were no significant between-group differences in energy expenditure variables. CONCLUSION: This group of women met the cost of lactation principally via increased energy intake.

Adult↗
PubMed1999

Estimating energy intake of urban women in Colombia: comparison of diet records and recalls.

As part of a larger study of energy-nutrition, we compared the performance of 24 h diet recalls with estimated diet records kept by trained observers. The subjects were economically disadvantaged women (n = 85) in the city of Cali, Colombia. A 24 h recall and an estimated diet record were collected for each woman at 0 and approximately 3 and 6 months. Energy intake obtained from the estimated dietary records was validated against energy expenditure and used as the reference method. Energy and macronutrient intake were calculated from published food composition tables and proximate analyses of common foods. The number of food items consumed per woman per day, total and in each of 16 food groups, was tabulated. Energy and macronutrient intakes were 11-13% lower in the 24 h recalls. The discrepancy energy could be largely accounted for by the lower number of food items in the recalls. The number of food items in eight of 16 food groups was significantly lower in the recalls compared to the records. Underreporting on the recalls was a general tendency in these subjects and not clearly related to average energy intake. We conclude that 24 h diet recalls underestimate energy and nutrient intake in this population and are not suitable for studies of human energetics.

Body Composition↗
PubMed1998

Increased muscular efficiency during lactation in Colombian women.

OBJECTIVE: To determine the muscular efficiency of lactating women and compare it to that of nonpregnant, nonlactating (NPNL) women. DESIGN: The study was retrospective. The subjects were selected randomly in the two groups and studied on three occasions (rounds) separated by approximately three months. SUBJECTS: There were 109, 101, and 80 NPNL women and 45, 31 and 16 lactating women in rounds 1, 2 and 3 respectively, 19-43 y of age, living under economically deprived conditions in Cali, Colombia, who participated in the study. METHODS: Muscular efficiency was measured as delta efficiency on a cycle ergometer. RESULTS: Muscular efficiency was significantly higher in lactating women in all three rounds compared to NPNL women. In six women it was possible to measure efficiency at variable times prior to their pregnancies, and again during lactation about three months post partum. There was a statistically significant (P = 0.03) increase in muscular efficiency during lactation. CONCLUSION: Lactation results in about a 5% increase in muscular efficiency which may contribute to the adaptation of the mother to the increased energy demands associated with lactation.

Adult↗
PubMed1997

Living on the edge: dietary strategies of economically impoverished women in Cali, Colombia.

Economically impoverished women in Cali, Colombia, have restricted access to food in a city where food is abundant. Ethnographic observations, interviews and 2 day food records were used to better understand the coping strategies used by a group of these women (n = 85) to maintain adequate levels of energy intake. Anthropometric indicators of nutritional status were normal for the group. Interview data revealed that the ability to purchase food was a concern for 58% of the women. When faced with a restricted ability to purchase food, the women indicated they made compromises in meal composition, reduced portion sizes, and/or reduced the number of meals. They also relied on relatives, friends, neighbors, store credit, or local government programs for access to food. Changes in meal composition were identified in 17.1% of all diet records (n = 509). Low energy intake (defined as energy intake < or = 1.27 x BMR) was identified in 17.1% of all diet records. Carbohydrate consumption was significantly greater on low-energy intake days. The adequate nutritional status of this group of women suggests that their coping strategies are usually adequate to maintain energy intake, but the presence of uncertainty, the frequency of compromises in diet composition, and the frequency of low-energy intake days suggest that these women are at risk for undernutrition.

Adaptation, Psychological↗
PubMed1997

Daily energy expenditure of women by factorial and heart rate methods.

To compare the minute-by-minute heart rate (Flex-HR) reference method with the factorial method, total daily energy expenditure (TDEE) and the pattern of daily energy expenditure (EE) were measured in nonpregnant, nonlactating women 19-40 yr of age, working at their household chores (at home, N = 20) or for remuneration in various kinds of employment (at work, N = 28). The factorial method used three data sets described in the compendium of Ainsworth et al. (CMD), FAO/WHO/UNU (FAO), and James and Schofield (J&S). Measurements were repeated on three rounds separated by 3 months. The TDEE by Flex-HR method, by round, was 9.0 +/- 2.6, 8.9 +/- 1.4, and 10.3 +/- 3.4 MJ.d-1 in the women at home and 9.7 +/- 2.3, 11.4 +/- 3.2, and 11.3 +/- 3.6 MJ.d-1 in the women at work. Values using the CMD data set were not significantly different from Flex-HR in either group in any round, but FAO and J&S data sets gave significantly lower values than both of the former methods in all rounds. The same statistical results were obtained for the patterns of activity. Since the timing of activities by the observers was the same, it is concluded that the major source of error in applying the factorial method is in the values for energy expenditure assigned to the various activities and the ability of investigators to properly judge EE from available data sets.

Activities of Daily Living↗
PubMed1997

Understanding the nutrition of poor urban women: ethnographic and biological approaches.

To better understand how women respond to conditions of urban poverty in a developing country a sample of 85 women living in Cali, Colombia was studied. Anthropometric indicators of nutritional status were normal for the group. However, many women indicated that they did not always have sufficient money to purchase food, and described the strategies they used when financial resources were inadequate. These strategies included changes in meal composition, reductions in food portion size, and reductions in the number of meals eaten. Evidence of the use of these strategies was identified in 17.1% of all diet records (n = 509). The adequate nutritional status of this group of women suggests that their strategies were usually successful in maintaining adequate energy intake, but the frequent use of these strategies suggests that the women are potentially at risk for undernutrition.

Adult↗
PubMed1996

Energy expenditure of urban Colombian women: a comparison of patterns and total daily expenditure by the heart rate and factorial methods.

The heart rate and factorial methods of measuring both total daily energy expenditure (TDEE) and the daily pattern of energy expenditure (EE) were compared in nonpregnant, nonlactating women aged 19-43 y living in urban conditions of economic deprivation. The methods were applied on each of 2 successive days. There were no significant differences between the 2 d by either method. Women who worked at their household chores at home (n = 29) and those who also worked for remuneration (at work) in various kinds of employment (n = 23) were compared. The factorial method gave values for TDEE and for the pattern of EE that were significantly lower than those obtained by the heart rate method. This was related to lower values for EE for certain activities obtained from the literature than for values measured in these subjects. Women at work had significantly higher values for both TDEE and for the pattern of EE than did those at home. The TDEE at home by the heart rate method was 8.83 +/- 1.94 MJ/d and at work was 9.99 +/- 1.91 MJ/d (P = 0.036); this difference disappeared when adjusted for body weight or fat-free mass. Physical activity levels were 1.83 +/- 0.43 for women at home and 1.90 +/- 0.46 for women at work, which indicate moderate to heavy work. The factorial method should be used with measured EE values in the present subject population. The heart rate method can detect differences in TDEE and in the pattern of EE between women engaged in different activities and may offer an experimental approach to the study of the effects of daily variations in EE on nutritional energy intake.

Adult↗
PubMed1994

Variation of the basal metabolic rate and dietary energy intake of Colombian women during 1 y.

Anthropometry, basal and resting metabolic rates (BMR and RMR), and dietary energy intake were measured on five occasions approximately 3 mo apart for 1 y in 21 nonpregnant, non-lactating women 20-42 y of age living under deprived economic conditions in Cali, Colombia. There was a significant increase in body weight (1-1.5 kg) because of increased body fat during the last two rounds of measurement. BMR was elevated in the first round but fell to stable values that did not vary significantly from 3 to 12 mo. The intraindividual CV of BMR was 8.3% whereas the intraindividual CV of dietary energy intake was 17%. Measured BMR was closely related to the BMR estimates provided by the empirical equations of Schofield, but significantly higher than estimates from the equations of Henry and Rees. RMR-BMR ratios were very close to those published by FAO/WHO/UNU. Autocorrelation analysis of BMR showed weak ability to predict subsequent variation of BMR over time and is consistent with random variation of the data.

Adult↗
PubMed1994

Body composition of Colombian women.

Measurements of anthropometry and total body water (TBW) were made in 99 women 19-44 y of age living in socioeconomically deprived circumstances in Cali, Colombia. TBW was measured by dilution of deuterium oxide. An empirical equation for estimating lean body mass (LBM) was derived and applied satisfactorily to an independent study group. Comparisons were also made with body-composition values obtained by the Durnin and Womersley equations and an equation derived from rural women living in Guatemala. Neither set of equations was suitable for use with the Colombian subjects because both significantly overestimated LBM and therefore underestimated body fat. Lower values of standing height in older women suggest that they may have been subjected to more severe undernutrition during their growth than the younger subjects. When compared with a group of US women, Colombian subjects were less physically fit and had greater subcutaneous-fat deposits, which were distributed over the trunk and limbs, whereas body mass indexes and waist-hip ratios were not significantly different.

Adipose Tissue↗
PubMed1992

Basal metabolic rate of Colombian children 2-16 y of age: ethnicity and nutritional status.

Measurements of basal metabolic rate (BMR) were made in 528 children 2-16 y of age living in underprivileged areas of the city of Cali, Colombia (153 control and 186 undernourished boys, 93 control and 96 undernourished girls). The data are related to BMR calculated from the equations of Schofield and to estimates of the lean body mass (LBM). The ethnic composition of the subjects was 80% mestizo (mixed European and South Amerindian ancestry), 15% black, and 5% white. The data do not show any variations due to race in these subjects. The Schofield equations overestimate the BMR of boys by approximately 6% whereas the estimation of BMR in girls is not significantly different from measured values. More than 65% of the variation in BMR of both nutritionally normal and undernourished boys and girls is explained by variation in body size as estimated by the LBM.

Adolescent↗
PubMed1990

Daily pattern of %VO2max and heart rates in normal and undernourished school children.

The pattern of usage of the VO2max, expressed as %VO2max during ordinary school days, with minute-by-minute heart rate recording, was studied in 106 boys and 83 girls, 6-16 yr of age divided into three age groups (6-8, 10-12, and 14-16 yr), living under economically deprived conditions in Colombia and classified as nutritionally normal or marginally malnourished. In a 12-h period, the 12 groups of children spent, on the average, 7-10 h at less than 30% VO2max, 1.5-4 h at 30-50% VO2max, and an accumulated time of 20-60 min above 50% VO2max. The latter occurred in short bursts rather than during sustained periods. There was a statistically significant but small decrease (approximately -3%) in the average 12 h %VO2max with age but no effects of sex or nutritional status. The overall average was about 25% VO2max in all groups. The data may suggest the existence of the regulation of physical activity to some level easily sustainable for long periods. Expressing the data as 30 min averages during 5 h of school and 5 h of free-time activity allows for the possibility of seeing group differences during shorter periods of time. This may prove useful in exercise training programs and studies of effort in the workplace.

Adolescent↗
PubMed1990

Physical activity and energy expenditure in undernutrition.

The most accurate measurement of energy expenditure (EE) in free-living individual subjects is by the doubly-labelled water technique. The minute-by-minute heart rate (fH) method, while not yet suitable for individuals, will give excellent measurements of EE in small groups of subjects as well as the pattern of EE while wearing the fH recorder. In adults, the few studies available indicate that chronic energy deficiency (CED) results in decreased energy expenditure. In pre-school children, CED results in decreased activity as a first line of defense against decreased rate of growth. In marginally malnourished school children, the lower levels of EE are the results of their smaller size. However, they are unable to cope with situations of increased activity above ordinary levels. The relative effort exerted by control and undernourished boys and girls 6-16 y of age averaged approximately 25% VO2 max during 12 h of school days. There was a -3% change with age but there were no sex or nutritional status effects on average % VO2 max. It is suggested that this relative constancy in % VO2max in such disparate groups may be indicative of some physiological regulation of activity levels.

Energy Metabolism↗
PubMed1989

The use of heart rate monitoring in the estimation of energy expenditure: a validation study using indirect whole-body calorimetry.

1. A modified heart rate (HR) method for predicting total energy expenditure (TEE) was cross-validated against whole-body calorimetry (CAL). Minute-by-minute HR was converted to energy expenditure (EE) using individual calibration curves when HR exceeded a pre-determined 'FLEX' value designed to discriminate periods of activity. ('FLEX' HR was defined as the mean of the highest HR during rest and the lowest HR during the lightest imposed exercise.) Sedentary EE (below FLEX) was calculated as the mean EE during lying down, sitting and standing at rest. Sleeping EE was calculated as basal metabolic rate (BMR) predicted from standard equations. 2. Calibration curves of oxygen consumption v. HR for different postures at rest and during exercise were obtained for twenty healthy subjects (eleven male, nine female); mean r 0.941 (SD 0.04). The mean FLEX HR for men and women were 86 (SD 10) and 96 (SD 6) beats/min respectively. 3. Simultaneous measurements of HR and EE were made during 21 h continuous CAL, which included 4 x 30 min imposed exercise (cycling, rowing, stepping, jogging). HR exceeded FLEX for a mean of 98 (SD 41) min. Mean TEE by CAL (TEE.CAL) was 8063 (SD 1445) kJ. 4. The HR method yielded a mean non-significant underestimate in TEE (TEE.HR) of 1.2 (SD 6.2)% (range -11.4 to +10.6%). Regression of TEE.HR (Y) v. TEE.CAL (X) yielded Y = 0.868 X + 927 kJ, r 0.943, SE of the estimate 458 kJ, n 20. 5. The satisfactory predictive power and low cost of the method makes it suitable for many field and epidemiological applications.

Adolescent↗
PubMed1989

Energy expenditure/basal metabolic rate ratios in normal and marginally undernourished Colombian children 6-16 years of age.

Measurements of basal (BMR) and resting (RMR) metabolic rates, maintenance (MEE) and total daily energy expenditures (TDEE) have been made in Colombian children 6-16 years of age classified as nutritionally normal (boys, n = 129; girls, n = 72) and marginally undernourished (boys, n = 171; girls, n = 74). TDEE/BMR ratios were calculated for comparison with those suggested by FAO/WHO/UNU (1985) and to provide data for children less than 10 years of age. TDEE was measured in free-living, individually calibrated subjects by the heart-rate method. TDEE/BMR increased significantly with age in boys from 1.60 to 1.84 in control subjects and 1.46 to 1.92 in undernourished boys. There was no significant increase with age in the girls. There were no statistically significant differences between nutritional groups but girls had significantly lower values than boys. There was a greater rate of increase in TDEE than BMR with age and girls spent more time in light activities and less in high level activities than boys.

Adolescent↗
PubMed1988

Energy expenditure from minute-by-minute heart-rate recording: comparison with indirect calorimetry.

Total daily energy expenditure (TDEE) and energy expended in activity (EAC) were estimated by the minute-by-minute heart-rate method in 22 (16 men, 6 women) individually calibrated subjects and compared with values obtained by whole-body indirect calorimetry. Subjects followed four activity protocols during the 22 h in the calorimeter; no exercise (n = 6) and 2 (n = 5), 4 (n = 4), and 6 (n = 6) 30-min bouts of exercise on a bicycle ergometer at varying intensities. There were no statistically significant differences between the two methods in TDEE or EAC in any of the sex or protocol groupings. The regression of TDEE by heart rate on TDEE in the calorimeter was y = 0.92x + 1.0 MJ; (r = 0.87, SEE = 0.91 MJ). The heart-rate method also follows the varying activity patterns of individuals and can be used to closely estimate the TDEE and EAC of even small (n = 4-6) groups of subjects. In the present measurements, it gave a maximum error of TDEE for individuals of +20% and -15%.

Adult↗
PubMed1988

Basal metabolic rate of normal and marginally undernourished mestizo children in Colombia.

The basal metabolic rate (BMR) was measured in mestizo children 6-16 years of age living under economically deprived conditions in Colombia. Of a total of 239 boys and 126 girls, 137 boys and 72 girls were classified as marginally malnourished. Differences in BMR by age, sex and nutritional group could be accounted for by differences in lean body mass. The Schofield equations were found to overestimate BMR significantly in the boys. However, the estimates in girls were not significantly different from measured values.

Adolescent↗