Marta N.C.M. Vieira

Validation of a food frequency questionnaire for assessing dietary nutrients in Brazilian children 5 to 10 years of age

OBJECTIVE This study aimed to assess the relative validity of a food frequency questionnaire (FFQ), previously validated to measure usual intakes in adults, for measuring dietary intakes in children 5 to 10 y of age. METHODS Dietary intakes were measured using an FFQ and a 3-d dietary record. Healthy children, 5 to 10 y old (n = 151), were recruited from public schools and asked to answer the questions in the FFQ and to provide non-consecutive 3-d dietary records based on reported estimated portion sizes. Paired sample t tests and Pearsons correlation coefficients were conducted to determine whether the two instruments reported similar values for energy and nutrients. The agreement of quartile categorization between the two instruments was also examined. RESULTS Estimated energy and nutrient intakes derived from the FFQ were significantly higher than those derived from 3-d dietary records. As expected, Pearsons correlations increased after adjusting for residual measurement error, presumably due to exclusion of the high within-person variability in intake of these nutrients. Moderate to high (r > 0.50) correlation coefficients were verified for some nutrients such as calcium, folate, vitamin B2, vitamin A, and vitamin C. CONCLUSION This FFQ, originally developed for use in adults, appears to overestimate usual energy and nutrient intakes in children 5 to 10 y of age. Further work is necessary to conduct a calibration study to establish adequate portion sizes before instrument adoption in this population.

Harris-Benedict equation for critically ill patients: Are there differences with indirect calorimetry?

PURPOSE The aim of this study was to compare the measured energy expenditure (EE) and the estimated basal EE (BEE) in critically ill patients. MATERIALS AND METHODS Seventeen patients from an intensive care unit were randomly evaluated. Indirect calorimetry was performed to calculate patients EE, and BEE was estimated by the Harris-Benedict formula. The metabolic state (EE/BEE x 100) was determined according to the following criteria: hypermetabolism, more than 130%; normal metabolism, between 90% and 130%; and hypometabolism, less than 90%. To determine the limits of agreement between EE and BEE, we performed a Bland-Altman analysis. RESULTS The average EE of patients was 6339 +/- 1119 kJ/d. Two patients were hypermetabolic (11.8%), 4 were hypometabolic (23.5%), and 11 normometabolic (64.7%). Bland-Altman analysis showed a mean of -126 +/- 2135 kJ/d for EE and BEE. Only one patient was outside the limits of agreement between the 2 methods (indirect calorimetry and Harris-Benedict). CONCLUSIONS The calculation of energy needs can be done with the equation of Harris-Benedict associated with lower values of correction factors (approximately 10%) to avoid overfeeding, with constant monitoring of anthropometric and biochemical parameters to assess the nutritional changing and adjust the infusion of energy.

Body Composition in Obese Adolescents: Deuterium Oxide Dilution Method, Bioelectrical Impedance and Predictive Equations

Background & Aims: Considering that obese adolescents present alterations in the quantity of body water, fat and lean body mass, specific formulae need to be adjusted through a reference method. This study aimed to describe and compare the body composition data obtained by bioelectrical impedance analysis (BIA) and the deuterium oxide dilution method (DODM). To identify possible correlations and agreement between these two techniques and adjust linear regression models for the prediction of DODM values on the basis of BIA results. Methods: Anthropometric measurements were accomplished for obese adolescents, and their body composition was assessed by the BIA and DODM techniques. Results: Compared to the DODM technique, BIA overestimated the fat-free mass (FFM) and the total body water (TBW) and underestimated the fat mass (FM). There was a significant positive correlation but no agreement between the FFM (kg), FM (kg), and TBW (L) data achieved via DODM and BIA. The application of linear regression model adjustments to the values measured by BIA enabled prediction of the DODM values for body composition in obese adolescents. Conclusion: These formulas have been demonstrated to improve the agreement between the two methods, so a more accurate tool that is closer to the DODM reference technique has been made available for use in clinical practice.

Hortaliças in natura ou minimamente processadas em unidades de alimentação e nutrição: quais aspectos devem ser considerados na sua aquisição?

Objective The objective of the present study was to assess the losses that occur when fresh vegetables are processed, to compare the cost of purchasing fresh and minimally processed vegetables, and to discuss the advantages and disadvantages of using minimally processed food items. Methods Correction factors for seven food items were calculated by determining their gross and net weights in triplicate with a digital scale. Mean, standard deviation and variation coefficient were calculated. The costs of gross weight considering the correction for net yield were compared with the costs of minimally processed vegetables supplied by the manufacturer during two different periods. Results The costs of minimally processed zucchini, carrot, chayote and arracacha were 8.6%, 14.1%, 4.6% and 13.5% lower than their respective fresh counterparts at time 1, a fact that did not repeat itself at time 2, when these vegetables were less expensive when bought fresh. Conclusion In conclusion, numerous factors associated or not with the food directly influence the magnitude of the losses that occur during processing. The working methods and final objectives of each foodservice should define which product is more advantageous since costs vary and production can be affected by seasonality and the supply and demand of the food item, with repercussions on the quality management of the foodservice.