** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** INCREASING EVIDENCE FROM VARIOUS STUDIES SUGGESTS THAT CONSUMING FRUITS AND VEGETABLES CONTAINING POLYPHENOLS, INCLUDING BERRIES, ESPECIALLY BLUEBERRIES IN PARTICULAR MAY INFLUENCE CARBOHYDRATE METABOLISM BY CONTROLLING POSTPARANDIAL GYLCEMIC RESPONSES AND FASTING HYPERGLYCEMIA, AS WELL AS IMPROVING INSULIN RESPONSE AND SENSITIVITY.HOWEVER, THE HYPOGLYCEMIC ACTIVITIES OF POLYPHENOL FRACTIONS OTHER THAN ANTHOCYANINS HAVE NOT BEEN PROPERLY UNDERSTOOD. THEREFORE, THE OBJECTIVE OF THIS RESEARCH IS TO INVESTIGATE THE POSSIBLE ROLES OF BLUEBERRY POLYPHENOLS IN PREVENTING METABOLIC SYNDROME-INDUCED DIABETES.WHOLE BLUEBERRIES WILL BE PROCESSED INTO FREEZE-DRIED POWDERS AND ASSAYED FOR TOTAL POLYPHENOLIC CONTENT, IN VITRO ANTIOXIDANT AND HYPOGLYCEMIC PROPERTIES AND THEN FORMULATED INTO FEED DIETS ACCORDING TO STANDARD METHODS. FIFTY 5 WEEK OLD MALE C57/B16 MICE WILL BE HOUSED 10 PER CAGE, ACCLIMATIZED FOR A WEEK AND THEN PLACED ON VERY HIGH FAT DIETS (VHFD) FOR 12 WEEKS TO INDUCE OBESITY, INSULIN RESISTANCE AND HYPERGLYCEMIA. THE MICE WILL BE PLACED ON INTERVENTION DIETS MADE UP OF VHFD CONTAINING EITHER 0, 5, 10, 15 AND 20G WHOLE FREEZE-DRIED BLUEBERRY FOR ADDITIONAL 13 WEEKS.FEED AND WATER INTAKE WILL BE MEASURED DAILY WHILE BODY WEIGHT WILL BE MEASURED WEEKLY. URINE, BLOOD SAMPLES, ORAL GLUCOSE TOLERANCE AND FASTING BLOOD GLUCOSE TESTS WILL BE COLLECTED AT BASELINE, MIDPOINT AND AT TERMINATION. AFTER THE 13 WEEKS PERIOD, THE RATS WILL BE ANESTHETIZED AND BLOOD, HEART, LIVER, KIDNEY AND ADIPOSE TISSUE COLLECTED FOR IN VIVO ASSAYS FOR BIOMARKERS OF OXIDATIVE STRESS, OBESITY AND DIABETES USING BIOCHEMICAL, MOLECULAR AND METABOLOMIC ANALYSES. THIS RESEARCH WILL ADVANCE KNOWLEDGE IN DIABETIC HEALTH EFFECTS OF BLUEBERRIES.