Effects of Increased Protein Intake and Exercise Training on Body Composition, Cardiovascular Health and Physical Performance

The primary purpose of this study is to examine the effects of increased healthy protein intake (25% of daily caloric intake as protein; 25% as healthy fats and oils; 50% as complex, unrefined carbohydrates) consumed as 6 small meals during the day in combination with exercise training 4 times per week, over a 16 week period in 25 overweight, but healthy males and females (30-60 yrs old). A secondary purpose is to compare the effects of consuming two of the 6 small meals during the day comprised of whole food protein source servings 20g/serving) with a matched group consuming whey protein for 2 daily protein servings (20g/serving). In the case of both groups, 1 serving will be consumed immediately following exercise [within 30 minutes] and 1 serving will be consumed 2 hours before going to bed. On non-exercise days, all participants will continue to consume 6 small meals per day in the same ratio of 25% lean protein, 25% healthy fats and oils, and 50% complex, unrefined carbohydrates but the groups will differ only in the composition of the last meal of the day consumed 2 hours before going to bed in which one group will consume protein (20g/serving) as whole food protein sources and the other group will consume a single serving of a whey protein supplement. The primary purpose of this study is to quantify changes in the following health outcomes at baseline and 16 weeks: total body muscle mass and fat mass (iDXA); abdominal fat mass (most highly related to cardiovascular and metabolic disease risk); blood sugar (glucose); blood lipids; insulin, aerobic fitness (assessed with a submaximal exercise test); and muscular strength (measured by 1 repetition maximum (RM) of the chest and leg press). The following additional measures will be assessed at baseline and 16 weeks: waist circumference; body weight, heart rate, blood pressure, and hunger (Visual Analog Scales).