Location: Healthy Body Weight Research
Project Number: 3062-51000-051-00-D
Project Type: Appropriated
Start Date: Oct 1, 2014
End Date: Sep 30, 2019
Objective 1: Identify psychological and physiological processes and factors that influence the motivation to exercise and to eat. Objective 1A. Determine whether incentive sensitization for physical activity is dependent on the dose and the pattern/intensity of physical activity. Objective 1B. Determine whether the level of negative energy balance influences the magnitude of alterations in food reinforcement. Objective 2: Determine whether the relative reinforcing value of vegetables or fruits can be increased through repeated exposure. Objective 3: Determine the effect of meal macronutrient composition on energy metabolism and substrate utilization and satiety. Objective 3A: Compare the effects of high- vs. low-protein breakfasts as components of two patterns of daily protein intake (even distribution of protein across all meals vs. a skewed distribution with most protein consumed at the evening meal) on energy metabolism, substrate oxidation, satiety and the reinforcing value of high-sugar, after-meal snack foods. Objective 3B: Determine the effects of consuming a sugar-sweetened beverage as part of low- (55% CHO, 15% PRO, 30% FAT) or high-protein (40% CHO, 30% PRO, 30% FAT) meals on energy metabolism and substrate oxidation, and satiety and RRV of high-sugar, after-meal snacks.
Achieving and maintaining healthy body weight underlies many critical aspects of health. The immediate choices people make about their foods and physical activities have cumulative effects that affect body weight and, ultimately, health. Yet, the motivational bases of those choices remain poorly understood; as are ways those choices may be moved towards healthier alternatives. This knowledge is needed for the development of new and effective tools to promote behavioral choices that support healthy body weight. This project addresses these needs by investigating how to increase the reinforcing value of physical activity, and ways to increase the reinforcing value of vegetables and fruits. It also will evaluate the motivating potential of providing real-time feedback on subject energy balance based on an analysis of breath. This project will yield empirical evidence that will inform dietary and physical activity guidelines and programs, and tools that can be used by workers in the health and fitness industries to help individuals make healthy choices regarding physical activity, diet, and maintenance of a healthy body weight.