Darna Dufour - Academia.edu (original) (raw)

Papers by Darna Dufour

The American Journal of Clinical Nutrition, Jun 1, 1996

Public Health Nutrition, 2020

Objective:Body fat distribution may be a stronger predictor of metabolic risk than BMI. Yet, few ... more Objective:Body fat distribution may be a stronger predictor of metabolic risk than BMI. Yet, few studies have investigated secular changes in body fat distribution in middle-income countries or how those changes vary by socioeconomic status (SES). This study evaluated changes in body fat distribution by SES in Colombia, a middle-income country where BMI is increasing rapidly.Design:We applied factor analysis to previously published data to assess secular changes in adiposity and body fat distribution in cross-sectional samples of urban Colombian women. Anthropometry was used to assess weight, height and skinfolds (biceps, triceps, subscapular, suprailiac, thigh, calf).Setting:Cali, Colombia.Participants:Women (18–44 years) in 1988–1989 (n 1533) and 2007–2009 (n 577) from three SES groups.Results:We identified an overall adiposity factor, which increased between 1988–1989 and 2007–2008 in all SES groups, particularly in the middle SES group. We also identified arm, leg and trunk adip...

The American Journal of Clinical Nutrition, 1999

Background: This study examined the components of energy balance in poor, free-living pregnant wo... more Background: This study examined the components of energy balance in poor, free-living pregnant women living in an urban setting of a developing country. Objectives: We tested the following hypotheses: 1) energy intake increases in pregnancy and is greater than when nonpregnant and nonlactating (NPNL), 2) basal metabolic rate (BMR) increases in pregnancy and the increase is positively correlated with prepregnancy fatness, and 3) energy expenditure in activity decreases in pregnancy and is lower than in NPNL women. Design: Pregnant women were studied at 14.8 ± 3.4 (n = 40), 25.0 ± 3.2 (n = 54), and 34.9 ± 2.4 (n = 43) wk gestation, and NPNL women at baseline (n = 114) and at 3 (n = 103) and 6 (n = 93) mo. Energy intake was measured by using estimated diet records and energy expenditure by using the flex heart rate method. Time allocation in physical activity was assessed by observation. Results: In pregnant women, body weight, BMR, and energy intake increased but total daily energy expenditure (TDEE) did not change significantly. There were no significant changes in time allocation to selected activities except for lying down. In comparison with NPNL control subjects, women in late pregnancy had higher energy intakes and BMRs. Values for TDEE were not significantly different, but pregnant women expended less energy in activity and allocated more time to 2 energy-saving activities and less time to 2 energy-demanding activities. Conclusion: A decrease in energy expenditure in activity and changes in time allocation are important ways in which pregnant women meet the energy demands of pregnancy.

The American Journal of Clinical Nutrition, 1994

Anthropometry, basal and resting metabolic rates (BMR and RMR), and dietary energy intake were me... more 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.

Medicine &amp Science in Sports &amp Exercise, 1997

To compare the minute-by-minute heart rate (Flex-HR) reference method with the factorial method, ... more 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&amp;amp;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&amp;amp;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.

American Journal of Human Biology, 2001

Anthropometric data from a Tukanoan population in the Vaupes region of Colombia and an Achuar pop... more Anthropometric data from a Tukanoan population in the Vaupes region of Colombia and an Achuar population in the Ecuadorian Amazon were compared relative to international references. The Tukanoans exploit an oligotrophic blackwater ecosystem, whereas the Achuar inhabit a resource rich montane ecosystem. Given this ecological distinction, three hypotheses regarding nutritional statuses were proposed: (1) Tukanoans are significantly shorter than the Achuar, indicating a greater degree of stunting; (2) Tukanoans are significantly leaner, indicating a greater degree of wasting; and (3) Tukanaons have significantly lower upper arm muscle area, indicating lower lean body mass. Z‐scores for height, weight‐for‐height, and estimated upper arm muscle area were determined and significant nutritional stress was assumed at z ≤ −2.0. Between population differences in z‐scores for height‐for‐age (ZHT), weight‐for‐height (ZWH), and upper arm muscle area (ZUMA) were examined using analysis of varianc...

American Journal of Physical Anthropology, 2018

American Journal of Human Biology, 1997

The heart rate (HR) value employed to separate resting and active portions of the calibration cur... more The heart rate (HR) value employed to separate resting and active portions of the calibration curves used to estimate energy expenditure (EE) from minute-by-minute HR recordings is called the flex-HR. The present study has characterized it, the resting HR and the average daily HR during the awake portion of the day (12-14 h) by comparing age, gender and nutritional status effects related to measured maximum oxygen consumption (V. O 2 max; ml/min/kg body weight) in school-aged Colombian children (145 boys and 132 girls), 6-16 years of age. The same HR variables have been individually measured in nutritionally normal, nonpregnant, nonlactating (NPNL; n ‫ס‬ 48), pregnant (n ‫ס‬ 26), and lactating (n ‫ס‬ 18) women, 19-43 years of age, on three occasions separated by 3 months. In general, the flex-HR followed the differences observed in resting and average daily HRs. All three values decreased with age in children, were higher in girls than boys, and did not exhibit differences between nutritionally normal and undernourished children. All three HRs had a statistically significant negative relationship with V. O 2 max in boys but not in girls. NPNL and lactating women showed no significant change in the mean values of the repeated HR measurements but exhibited maximum individual differences of flex-HR of −56 to +42 beats/min. Pregnant women had higher HRs in all 3 rounds of measurement compared to NPNL subjects. The data support the generalization that the flex-HR method of estimating EE is appropriate in groups of subjects but not in individuals, and that individual calibration of subjects close to the time of application to the making of EE measurements is an important feature of its use. Am.