This Is AuburnElectronic Theses and Dissertations

Resting Metabolism and Metabolic Responses to Solid and Liquid Meals in Sedentary and Exercising College-Age Males




Ratcliff, Lance

Type of Degree



Nutrition and Food Science


Differences in resting metabolic rate (RMR) were measured in a total of 29 sedentary and exercising college-age males, as were their metabolic responses (diet-induced thermogenesis, DIT) to solid and liquid meals. Subject classification was based on habitual exercise. A group of 9 males was classified as sedentary, 11 males were classified as endurance (aerobic) exercisers, and 9 males were classified as weight lifters (resistance exercise). Resting metabolism was measured soon after waking; DIT for each meal was measured immediately following meal consumption, and then every 30 minutes for 3 hours. RMR and DIT were measured via indirect calorimetry, height was determined via stadiometer, and all body composition meaurements were done with bioelectrical impedance. No significant differences existed between groups for age, body mass index (BMI), percent body fat, fat-free mass (ffm), percent ffm, and hydration. Moreover, no significant differences existed in DIT based on meal form (Eta2 = 0.049, F = 1.336, p = 0.258). However, there was a significant overall metabolic increase based on group (Eta2 = 0.271, F = 4.844, p = 0.016). Specifically, both exercise groups had a significantly (p < 0.05) greater RMR when compared to the sedentary group; this increased RMR indicated that the exercise groups expended more energy expended more energy at rest than did the sedentary group. There were no significant RMR differences between the exercising groups (p = 0.843). RMR and DIT were negatively correlated (r = -0.38; p = 0.023). The variables positively correlated with RMR include ffm (r = 0.59; p < 0.001), and BMI (r = 0.39; p = 0.020). In conclusion, these findings give further support to the importance of exercise, specifically frequent and intense exercise, in amplifying resting metabolic rate and increasing total energy expenditure.