William Troy Donahoo

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BACKGROUND Many commercially available pedometers undercount, especially at slower speeds. We examined the effects of age, obesity, and self-selected walking speed on pedometer accuracy. We also compared the accuracy of piezoelectric and spring-levered pedometers at slow walking speeds. METHODS Study 1: 259 subjects walked on a motorized treadmill at two(More)
PURPOSE OF REVIEW To review factors contributing to variation in total daily energy expenditure and its primary components: (1) resting metabolic rate; (2) diet-induced thermogenesis; and (3) activity thermogenesis, including exercise energy expenditure and nonexercise activity. For each component, the expected magnitude of intra-individual variability is(More)
OBJECTIVE To determine if total calcium (Ca(2+)) intake and intake of Ca(2+) from dairy sources are related to whole-body fat oxidation. DESIGN : Cross-sectional study. SUBJECTS A total of 35 (21 m, 14 f) non-obese, healthy adults (mean+/-s.d., age: 31+/-6 y; weight: 71.2+/-12.3 kg; BMI: 23.7+/-2.9 kg m(-2); body fat: 21.4+/-5.4%). MEASUREMENTS Daily(More)
BACKGROUND: Although the effects of resistant starch (RS) on postprandial glycemia and insulinemia have been extensively studied, little is known about the impact of RS on fat metabolism. This study examines the relationship between the RS content of a meal and postprandial/post-absorbative fat oxidation. RESULTS: 12 subjects consumed meals containing 0%,(More)
Research Group 2002; Ornish, 2005]. However, it is impossible to draw final conclusions from these studies in that they do not have a higher fat control group, they often incorporated additional lifestyle interventions, and there is difficulty in maintaining the very low fat diets, which leads to high drop out rates. Despite the findings of post hoc(More)
OBJECTIVE To reassess the relationship between body fat and fasting leptin concentrations comparing plasma vs. serum assessments of leptin; ratios vs. regression adjustment for body composition; fat and lean mass vs. percent body fat; and gender-, ethnic-, and age-related variations. RESEARCH METHODS AND PROCEDURES Subjects included 766 adults from the(More)
Metabolic adjustments occur with weight loss that may contribute to a high rate of weight regain. We have previously observed in obesity-prone, obese rats that weight reduction is accompanied by a suppression in resting metabolic rate beyond what would be predicted for the change in metabolic mass. In the present study, we examine if this adjustment in(More)
As exercise can improve the regulation of glucose and carbohydrate metabolism, it is important to establish biological factors, such as sex, that may influence these outcomes. Glucose kinetics, therefore, were compared between women and men at rest, during exercise, and postexercise. It was hypothesized that glucose flux would be significantly lower in(More)
BACKGROUND Whether resistance exercise is as effective as aerobic exercise for body-weight management is debated. PURPOSE To compare 24-h energy expenditure (EE) and macronutrient oxidation elicited by comparable bouts of stationary cycling (BK) and weightlifting (WTS). METHODS 24-h EE and macronutrient oxidation were measured in 10 nonobese male(More)
Seven nonobese adult females (40 +/- 8 years) were studied in a room calorimeter on a day that resistance exercise (REX) was performed (4 sets of 10 exercises) and on a nonexercise control day (CON). Twenty-four-hour energy expenditure (EE) on the REX day (mean +/- SD, 2,328 +/- 327 kcal.d(-1)) was greater than CON (2,001 +/- 369 kcal.d(-1), p < 0.001). The(More)