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Evaluation of protocols for assessing energy needs in overweight and obese adults

by Hodges, Valerie Anne.

Abstract (Summary)
Objectives To examine protocols for adjusting weight in the Harris- Benedict equation (HBE) and to evaluate recently developed predictive equations, including those specific for this study (SS), one for normal weight and one for overweight/obese subjects, for accuracy in estimating basal energy expenditure (BEE) of overweight and obese adults. Design Indirect calorimetry and dual energy x-ray absorptiometry (DXA) were used to assess measured BEE (MBEE) and body composition, respectively. Identification of fat-free mass (FFM), total mass minus fat mass, in overweight/obese and normal weight individuals allowed calculation of mean excess FFM (FFM above that carried at normal weight) in overweight/obese subjects. Accuracy of equations developed in this study, those developed by Owen, Mifflin, and Harris-Benedict, and the HBE using weight adjustments of adding 25% and 60% of excess weight to standard weight for height (SBW) were assessed in normal weight and overweight/obese subjects. A predictive value within 10% of MBEE was considered accurate. 56 Subjects/Setting Fifty-three overweight or obese healthy adults that were > 125% SBW with body mass index (BMI) ranging from > 25 to 45 kg/m2 were matched for gender, height (±1 inch) and age (±1 year) with healthy adults of normal weight, ±10% of SBW, and BMI’s ranging from 19 to 26 kg/m2. Statistical Analysis Performed Linear multiple regression was used to derive new predictive equations for normal and overweight/obese subjects. A one-way analysis of variance was used to analyze differences in predictive equations compared to MBEE. Significance was defined at 0.05. Results Based on body composition data from normal and overweight/obese subjects, mean excess FFM in overweight/obese individuals was 17%. Since others have found adjusting SBW by at least 25% of the excess weight under predicted MBEE for 72% of the overweight/obese subjects, factors in addition to FFM are responsible for increased BEE in this population. SS, Owen, and Mifflin equations predicted MBEE within ±10% for about 75% of all normal weight subjects and about 65% of the overweight/obese subjects. The HBE with 57 weight adjustments to represent SBW plus 25 or 60% of excess body weight accurately predicted MBEE for 78% of those > 125 to 150% SBW and for 63% of those > 150% SBW, respectively. Applications/Conclusion Although newer equations predict MBEE within ±10% for about 75% and 65% of normal weight and overweight/obese individuals, respectively, they are unlikely to replace utilization of the HBE in practice. Results of the present study indicate similar accuracy for HBE in assessment of overweight/obese clients when 25% and 60% of excess weight is added to SBW for individuals > 125 to 150% and > 150% SBW, respectively. 58
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School:The University of Texas at Austin

School Location:USA - Texas

Source Type:Master's Thesis

Keywords:basal metabolism proteins overweight persons

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