Description: The role of Core D is to perform dietary assessments, anthropometric measurements, body composition/energy metabolism measurements, and nutrition counseling and support. A complete list of the study parameters is presented in Table 1. Project 1 conducts the continuing surveillance of the "Nutrition for Life" (NFL) cohort that has currently been followed from one to three years and involves comprehensive longitudinal data on each subject. This Core will continue to set the protocols, quality control, training, and analyses on the cohort data. This cohort data includes dietary assessments (3-day food record (3DFR) and food frequency questionnaire (FFQ)), anthropometric measurements (weight, height, skin folds, hand grip, and circumferences), body composition measurements (bioelectrical impedance (BIA) and dual energy x-ray absorptiometry (DEXA)), and energy expenditure and metabolism measurements. This core will also provide nutrition counseling and support for the cohort. Project 1 will now include use of DEXA for determinations of body composition (yearly). Project 2 will utilize most of the services and measurements listed in this Core. This project has a population study group of 100 with each participant enrolled for one year. An average of 20 persons per year will be enrolled in the study. Individual nutrition counseling will be used for this study due to the specific nature of the nutrition interventions and the staggering of enrollment. Use of this Core?s services by Project 2 is delineated in the table on Page 381. Project 3 will contain three studies and will utilize many of the services and measurements offered in this Core (table on page 381). Study 1 will include only NFL participants and will not require any additional measurements for the NFL participants. Study 2, cohort sub-study with intensive metabolic measurements, will have 50 participants with each participant enrolled for one year. Study 3, Metformin for abdominal adiposity, will have 30 participants and will last for six months. Individual nutrition counseling will be utilized for this project because of the more detailed and instructional nature of the nutrition intervention and the importance of tracking. Staggered recruitment also necessitates individual counseling. Project 4 will be carried out at two sites (Children?s Hospital, Boston, MA; and Rochester Medical Center, Rochester, NY) by Tracie Miller, M.D. Procedures and protocols for the methods cited in this Core have already been adapted for this special population of infants and children.