Nutritional Treatment of Overweight Adolescents With Cardiovascular Risk Factors (PowerUp)

Overview

This study is designed to evaluate the efficacy of two diets, a low glycemic load diet and a low saturated fat diet, in the treatment of adolescents with some heart disease risk factors associated with being overweight, such as high blood pressure, pre-diabetes, and cholesterol problems. The objective of the study is to determine which diet improves these risk factors more. The design of the study is a modified feeding study, which requests that the participants eat all and only the food provided by the study for 8 weeks, most days per week. Dietary counseling by phone will continue between 2 and 6 months of the study and the effects of this maintenance period will be assessed at 6 months time.

The prevalence of obesity and overweight among children is high, and increasing. Metabolic syndrome, a recently recognized consequence of obesity, is known to confer an elevated risk for cardiovascular (CV) disease and diabetes type 2 in adults. The primary treatment for metabolic syndrome is lifestyle modification, including dietary changes. However, little is known about how dietary composition, as distinct from decreased caloric intake and weight loss, alters metabolic syndrome abnormalities in children. Moreover, the optimal pediatric nutritional strategy for prevention and treatment of metabolic syndrome is unknown. The overall goal of this research protocol is to evaluate two nutritional approaches to pediatric metabolic syndrome in post-pubertal overweight adolescents, a low saturated fat diet and a low glycemic load (GL) diet. The design of the protocol is a short-term, modified feeding study that evaluates the efficacy of these two nutritional approaches with equal weight loss goals. Outcome measures will include the percent changes from baseline to the end of the intervention period (8 weeks) in metabolic abnormalities, inflammatory cytokines and adipokines, and non-invasive tests of vascular function. Metabolomic profiles are measured at baseline and 8 weeks in a subset of the participants. To facilitate compliance and adherence, participants chose from a menu of food choices and food will be delivered to participants homes to supply most of the meals and snacks participants consume. Participants will receive weekly personal nutritional counseling to enhance compliance with frequent phone follow-up. Subsequent to the feeding portion of the intervention, participants are counselled by phone at least on a monthly basis and the effects of this maintenance phase is measured at 6 months.