Overweight and obesity have been increasing over the four past decades with linkage between excess body weight and coronary heart disease, type 2 diabetes (T2D) and premature death. Concomitantly, since the 1950?s, the number of processed food products appearing on grocery store shelves and the number of fast food restaurants in the US increased over 200%. Highly processed or ultra-processed foods (UPFs), rich in added sugar, fat, sodium, and additives, contributed over 55% of energy consumed by U.S. adults. These foods were also related to obesity in several studies, but not cardiometabolic outcomes. Better understanding of the role processed food plays in the development of obesity and chronic disease requires well characterized, longitudinal data about lifestyle, clinical outcomes, objective biomarkers, and repeated measures of dietary intake using a questionnaire with sufficient detail to correctly classify foods by processing level. The Coronary Artery Risk Development in Young Adults (CARDIA) study is uniquely suited to study the impact of long-term processed food intake on metabolism and development of obesity, cardiometabolic risk, and T2D across the life course in a large biracial cohort age 18-30 years at baseline (1985-86). The objective of this proposal is to conduct an ancillary study about processed food intake, metabolomics, and adiposity in the parent CARDIA year 35 exam: to assess dietary intake and measure adipose tissue depots by CT scan and metabolite markers in 3,270 black and white men and women. The central hypothesis is that repeated measures of energy intake (and other nutrients) from UPFs and related metabolite profiles predict obesity, adiposity, cardiometabolic risk, and T2D in 3,270 black and white men and women. The central hypothesis will be tested by pursuing three specific aims: 1) to examine intake of selected nutrients (energy, added sugar, fat, fiber, others) from UPFs at 4 examinations over 35 years, 2) to determine associations of repeated measures of energy and other nutrient intakes from UPFs at 4 exams with change in obesity, adipose tissue depots, cardiometabolic risk factors, and risk of T2D; and 3) to examine change in metabolite profiles associated with UPFs and their relationship to changes in weight, adipose tissue depots, cardiometabolic factors and risk of T2D. Biologic pathways will be identified based on metabolite profiles related to dietary intake and obesity- related and T2D outcomes. The proposed research is significant, because there is a need to know the long- term association of UPF intake with obesity and its pathologic correlates. The results will have an important impact because our findings 1) may challenge and clarify current diet policies - to consider not only nutrient and food group consumption, but also food processing and/or the formulation of food for a healthy eating pattern, and 2) may challenge food manufacturers to change food formulations by limiting or changing the type and/or amount of ingredients, thereby reducing the potential for developing some metabolic conditions.
Better understanding of the role of processed food intake in the development of cardiometabolic diseases and type 2 diabetes requires well characterized, longitudinal data, including dietary intake, lifestyle, and clinical outcomes as well as objective measures of diet, such as metabolite profiles. In the proposed study we will examine metabolite profiles associated with processed food consumption and their relationship to changes in weight, adipose tissue depots, cardiometabolic factors and risk of type 2 diabetes in black and white men and women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study.
