Browsing by Subject "Overweight persons"
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Item Comparisons of physical activity and dietary components in an overweight/obese population and their normal weight controls matched for gender, age and height(2004) Davis, Jaimie Nicole; Gillham, Martha B.The objectives of this study were: 1) to assess differences in voluntary physical activity and dietary components between an overweight/obese population and normal weight matched controls; 2) to assess the accuracy of commonly used activity factors, i.e., indices that represent physical activity in predictive equations for energy, established by the World Health Organization (WHO) and the Institute of Medicine (IOM) in the Dietary Reference Intakes (DRIs). Adults, aged 19-69 years, 53 overweight/obese and 53 normal weight subjects matched for gender, age (± 1 year) and height (±1 inch) were recruited from the local area and university community. Diets were assessed by the Block 60-item food frequency questionnaire, physical activity by the Yale Physical Activity Survey, and body composition by the dual energy X-ray absorptiometry. Resting energy expenditure was obtained by indirect calorimetry and later multiplied by a conversion factor to yield basal energy expenditure. A sub-sample of 62 adults, 31 in each group, wore an accelerometer, an instrument that detects body movement, for seven consecutive days. Accelerometer data showed that overweight/obese adults were less physically active, expended fewer kilocalories per kilogram of body weight, recorded fewer accelerometer counts throughout the week, and spent less time in moderate or greater intensity activity than their normal weight controls. Overweight/obese subjects consumed more total fat, saturated fat and cholesterol and less carbohydrate, complex carbohydrate and dietary fiber than controls. Reported intakes of dietary fiber and carbohydrate were inversely related to percent body fat with and without controlling for potential confounding factors, i.e., age, gender, physical activity-related energy expenditure and other macronutrients. Activity factors derived from accelerometers were significantly lower than those determined by the WHO and DRI methodology for normal but not overweight/obese subjects, suggesting that energy needs for many adults may be overestimated by using these prediction equations. In summary, limited physical activity-related energy expenditure, especially time spent in moderate intensity or greater activity, diet composition, especially low dietary fiber, and overestimation of energy needs by current prediction methodology are implicated in the etiology of obesity. These findings indicate areas of interest for future research and program development aimed at weight management and obesity prevention.Item Evaluation of protocols for assessing energy needs in overweight and obese adults(2004) Hodges, Valerie Anne; Gillham, Martha B.Accurate estimation of energy needs in overweight and obese adults is essential for long term weight management and during hospitalization, when in the presence of metabolic stress, significant underfeeding encourages loss of lean tissue. Modification of the Harris-Benedict equation (HBE) published in 1919 and derivation of new equations have attempted to accurately predict energy requirements in overweight/obese individuals. Objectives for this research were to examine protocols for adjusting weight in the HBE and to evaluate more recently developed predictive equations, for accuracy in estimating basal energy expenditure (BEE) of overweight and obese adults. Subjects were 53 overweight/obese and 53 normal weight healthy adults matched for gender, height, and age. Indirect calorimetry and dual energy x-ray absorptiometry were used to assess BEE and body composition, respectively. Study specific (SS) equations to predict BEE for normal and overweight/obese adults were derived using linear multiple regression. A hypothesis that excess fat-free mass (FFM), i.e., FFM above that carried at normal weight, in overweight/obese subjects would provide a tailor-made adjustment for weight in the HBE proved false. Mean excess FFM in our population was 17% while others had observed that adding 25% of the excess weight to standard body weight (SBW) in overweight/obese adults to be inadequate. SS, Owen and Mifflin equations predicted measured BEE (MBEE) within ±10% for about 75% of all normal weight subjects and about 65% of the overweight/obese subjects. Overweight/obese subjects were partitioned into two groups, those >125 to 150% and >150% of SBW, and weight was adjusted by adding 25% and 60% of the excess weight to SBW for the two groups, respectively. The HBE equation with the adjusted weights predicted MBEE within ±10% for 78% of those subjects >125 to 150% of SBW and more than 60% of those >150% SBW. Although newer equations predict MBEE within ±10% in about 75% and 65% of the cases for normal weight and overweight/obese individuals, respectively, they are unlikely to replace utilization of the HBE in practice. Results of the present study indicate accuracy for the HBE similar to that of the newer equations in assessment of overweight/obese subjects with additions of 25% and 60% of excess weight applied to SBW for individuals >125 to 150% and >150% SBW, respectively.