Based on the available literature suggesting a protective effect of adiponectin on the development of insulin resistance and coronary heart disease, the premise for the proposed study is that an increase in the number of servings of fruit/vegetables and whole grains as well as weight loss may increase adiponectin levels while following a standard fat- and calorie-restricted weight loss diet in the ongoing SMART Trial. The specific aims of this study are:1. To examine if the number of fruit and vegetables servings consumed is associated with changes in adiponectin levels at 6 and 12 months during a 24-month weight loss intervention.2. To examine if the number of servings of whole grain products consumed is associated with changes in adiponectin levels at 6 and 12 months during a 24-month weight loss intervention.3. To examine the effect of weight loss on adiponectin levels at 6 and 12 months of a 24-months weight loss intervention.4. To explore whether changes in the overall dietary glycemic index (GI) and/or glycemic (GL) are associated with changes in adiponectin levels at 6 and 12 months of the 24-month intervention.5. To explore if changes in adiponectin levels are associated with improved insulin sensitivity at the 6- and 12-month point of the intervention, as measured by the homeostasis model assessment ' insulin resistance (HOMA-IR).We are proposing a secondary data analysis from a randomized clinical weight loss trial of 115 healthy overweight/obese adults. The intervention includes personalized daily dietary goals and a weekly exercise goal in addition to attending 33 group sessions over 12 months. Total adiponectin is measured at baseline, 6 and 12 months, as well as fasting glucose and insulin. Dietary intake is assessed by two unannounced 24-hour dietary recalls at baseline, 6 and 12 months using the Nutrition Data System for Research software. Study endpoints are changes in adiponectin levels, body weight, HOMA-IR, GI and/or GL and the number of fruit and vegetables servings and whole grain products at 6 and 12 months relative to baseline values. Repeated measures models will be used to analyze the influence of fruit, vegetable and whole grain intake, weight loss and dietary GI/GL on changes in adiponectin levels. A relationship between changes in adiponectin and HOMA-IR will be explored with the repeated measure models.
|Program type||Predoctoral Fellowship|
|Effective start/end date||07/01/2009 → 06/30/2010|