2007 Annual Report 1a.Objectives (from AD-416) Determine the impact of an increase in physical activity level (PAL) on daily energy expenditure, long-term voluntary food intake, food selection and macronutrient. Identify differences in response to exercise between genders. Identify the changes in physiological markers of food intake, energy metabolism, and risk of chronic disease associated with an increase in PAL. 1b.Approach (from AD-416) In a crossover design, daily activity levels of male and female volunteers will be altered through a daily exercise intervention of approximately 60 minutes of walking 6 times per week for 14 weeks. Food selection and energy intake of subjects, will be determined by a combination of cafeteria-style feeding, controlled portion consumption and duplicate meal collection. Energy expenditure, macronutrient balance and PAL will be determined through a combination of doubly labeled water, indirect calorimetry and ambulatory monitoring of physical activity. Changes in weight, lean body mass and body fat content will be used as an indicator of energy balance. Fasting and meal challenged levels of insulin, leptin, ghrelin, cortisol and a variety of metabolites will be determined. These values will be correlated to previous and subsequent energy and macronutrient intake and energy balance. In addition, markers of chronic disease, such as blood pressure and blood lipids, will be determined and compared to values obtained during the baseline period. 3.Progress Report This project, which falls under National Program 107 Component 6, Relationship between Diet, Genetics, Lifestyle, and the Prevention of Obesity and Disease, has made notable progress in the development of facilities and methodologies for the study of energy metabolism in humans under both free-living and controlled conditions. Research in 2007 focused predominantly on dietary components believed to influence satiety factors and patterns of fuel selection, and their impact on body weight regulation. One double-blind feeding study, which built on previous research, was completed and one is in progress. The objectives of the first study were to. 1)determine the energy value of soluble dietary fiber and. 2)examine the impact of dietary fiber supplementation on self-reported satiety and satiety-related hormones. In addition to providing data relevant to the objectives of the project, this work provides data important for industry compliance with Food and Drug Administration (FDA) labeling requirements. The second study (currently in progress) examines the impact of polyphenols and catechins from tea on several measures of satiety and fat oxidation rate. Volunteers consume beverages containing placebo, caffeine, tea, tea enriched with catechins, or tea enriched with polyphenols. 4.Accomplishments Relationship between Physical Activity and Body Weight: National policy makers have included physical activity recommendations as part of diet and lifestyle recommendations; however there are only very limited data on which to base these recommendations. Data on physical activity was collected from 90 free-living individuals six times over 6 months in order to examine the relationship between physical activity and body weight. A positive relationship between the amount of physical activity and lower body fat was observed the the men. This work contributes data on physical activity and body weight to support the development of improved diet and lifestyle recommendations. This work addresses National Program 107, Component 6: Relationship between Diet, Genetics, Lifestyle, and the Prevention of Obesity and Disease. An Objective Systematic Approach to Interpreting Activity Monitoring Data: Prior to this work no systematic approach was available for interpreting activity monitoring data. This work provides a generally applicable system of processing algorithms which eliminates processes which involve subjective evaluation of the data. Processing and evaluation algorithms were developed for interpreting the results of activity-monitor data in the prediction of daily physical activity based on objective, statistical, step-wise procedures. These algorithms were developed using data collected from repeated measures of daily physical activity of 24 individuals who wore physical activity monitors for at least 20 h per day. This work is an essential step in evaluating data collected on physical activity and health necessary for health professionals and policy makers. This work addresses National Program 107, Component 6: Relationship between Diet, Genetics, Lifestyle, and the Prevention of Obesity and Disease. The Impact of Meal Patterns on Markers of Diabetes and Cardiovascular Disease: the combination of obesity and diabetes is the number one health-issue concern in the United States today. Patterns of diet consumption are believed to be a major contributor to this increasing problem. In a feeding study conducted at Beltsville in collaboration with scientists at the National Institute on Aging, consuming one meal versus several meals per day was shown to have a marked but variable negative impact on markers of diabetes and cardiovascular disease. These results will assist consumers and health professionals in understanding how diet impacts weight regulation, diabetes, and cardiovascular disease. This work addresses National Program 107, Component 6: Relationship between Diet, Genetics, Lifestyle, and the Prevention of Obesity and Disease. 5.Significant Activities that Support Special Target Populations None 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 12 Number of newspaper articles and other presentations for non-science audiences 5 Review Publications Paul, D.R., Kramer, M.H., Moshfegh, A.J., Baer, D.J., Rumpler, W.V. 2007. Comparison of two different physical activity monitors. BMC Medical Research Methodology. 7:(26). Available: http://www.biomedcentral.com/1471-2288/7/26. Stote, K.S., Baer, D.J., Spears, K., Paul, D.R., Rumpler, W.V., Strycula, P., Najjar, S.S., Ferrucci, L., Ingram, D.K., Longo, D.L., Mattson, M.P. 2007. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal weight middle-aged men and women. American Journal of Clinical Nutrition. 85:981-988.