Impacts of Wild Blueberries on Appetite and Weight Regulation

The objective is to complete a two-phase study to assess how wild blueberries impact regulation of appetite of overweight and obese men and women as well as to determine if wild blueberries can promote more effective weight loss than an isocaloric control. For phase I, the acute effects of consuming 1-cup of frozen wild blueberries mixed into ¾ C of low-fat yogurt will be compared to consuming an isocaloric serving of yogurt mixed with an artificially flavored and colored blueberry syrup. During acute testing, subjective ratings of appetite, glucose metabolism, and appetite-regulating hormones will be assessed. Phase II will consist of an 8-week feeding trial in which the same subjects will consume daily servings of yogurt mixed with either frozen wild blueberries or placebo syrup along with intensive counseling for weight loss. The hypothesis is that wild blueberries will reduce hunger by regulating appetite hormones and promoting beneficial glycemic and insulinemic responses and that daily consumption of wild blueberries will translate to improved adherence to a weight loss regimen and therefore greater weight and fat loss. Secondary aims for Phase II of this project will include exploring the impacts of blueberry consumption during weight loss on antioxidant status, inflammatory markers, blood lipid profiles, glucose status, dietary intake, physical activity and blood pressure.

Inclusion Criteria:Overweight or Obese (BMI 25-40)Exclusion Criteria:PregnancySmoking>5 kg wt fluctuation in the past 3 monthsexercising > 2 times per weekMedical conditions or medications that may affect body weight, metabolism, other outcome measuresAllergy to blueberries or yogurtAlready eating blueberries more than twice weeklyConsumption of >50 g/d alcohol