Location: Food Components and Health Laboratory2014 Annual Report
Diet is a modifiable factor that can influence the multitude of chronic health disorders that face the U.S. adult population, including type 2 diabetes, cardiovascular disease, some cancers, arthritis, endothelial dysfunction, and others. Through the experiments planned for this project, we will attempt to improve the understanding of the influence of diet on chronic disease. We will investigate direct effects of diet on cardiometabolic profile and additionally factors that influence weight gain, which increases risk for chronic disease. Objective 1. Determine the energy content of specific foods in the context of a mixed diet, and the absorption, metabolism and impact on biomarkers for health promotion of these foods or their macro and micro components. Objective 2. Determine the influence and interaction of the composition of food intake and exercise on glucoregulation, cardiometabolic profile, and metabolic flexibility (fuel management). Objective 3. Determine the extent to which the day-to-day variation in daily voluntary food intake, measured over at least 3 months, is related to diet composition, physical activity, and changes in physiological and metabolic markers related to energy balance, satiety and hunger.
Diet is a modifiable lifestyle factor that can influence the multitude of chronic diseases faced by an increasing proportion of the U.S. population, including type 2 diabetes, hypertension, vascular dysfunction, cardiovascular disease, cancer, and arthritis. Moreover, the widespread global prevalence of these diseases threatens the quality of life and places additional stresses on an already overburdened health care system. This project, through highly controlled human feeding studies, will target specific factors which influence risk for and development of chronic disease. First, research will be conducted to improve accuracy of the energy value of foods, which can impact weight gain, a risk factor for chronic disease. Second, research will be conducted to investigate dietary factors that can influence cardiometabolic profile, i.e. risk for cardiovascular disease, stroke, or diabetes. Third, we will study how diet influences voluntary food intake, again impacting weight gain, a risk factor for chronic disease. The outcomes of this research will provide a better understanding of 1) the energy content of specific foods in the context of a mixed diet, and the absorption, metabolism and impact on biomarkers for health promotion of these foods or their components, 2) dietary and lifestyle influences on diabetes and cardiovascular disease risk, and 3) the extent to which the day-to-day variation in daily voluntary food intake is related to diet composition. This research will fill knowledge gaps in the metabolism of macro and micro food components related to the development and management of obesity and chronic diseases, and provide a scientific basis for dietary recommendations and nutrition policy.
Progress was made for both objectives of this National Program 107 plan, focusing on Component 3 to provide a Scientific Basis for Dietary Guidance. Progress has been made addressing Problem Statement 3B: Identify Roles of Food, Food Components and Physical Activity in Promoting Health and Preventing Disease through studies on tree nuts and energy metabolism. Continuing with the line of research from the terminated project 1235-51530-009-00D, and research being conducted in conjunction with subordinate projects 1235-51530-010-01T and 1235-51530-010-06R, new research with tree nuts is being conducted. Recently, we found with almonds that the Atwater factors used for determining the energy (calorie) content for food labeling results in a calorie content that is 20% higher than the actual amount of calories in a serving of almonds. In recently completed research, we found a similar finding for walnuts – the current approach (Atwater) for calculating the energy content of walnuts overestimates the actual calories by 21%. The large discrepancies between the calculated and actual calorie content is because the Atwater system (used today to determine calories on food labels) overestimates the digestibility of macronutrients, particularly fat. Additional work is being conducted to determine if the form of almonds (raw, roasted, chopped or butter) effects fat digestibility and hence energy value. Continuing with the line of research from the terminated project 1235-51530-054-00D, a new project has been initiated to develop a new metabolic flexibility biomarker, which has application in the study of changes in diet and exercise on fuel management in humans. The new biomarker involves the characterization of an individual’s metabolic flexibility utilizing room calorimeters rather than the current method, which is based on glucose clamp data. Recruitment of research volunteers is ongoing.