Substrate Oxidation in Children in Response to High and Low Dairy Intake

The investigators propose a randomized trial comparing higher levels of dairy intake compared to lower levels of dairy intake. Participants will be 20 boys and girls, age 10-13, overweight (\>85%) who are currently consuming 1 or fewer servings of dairy per day. Each participant will be randomized to either higher or lower levels of dairy intake. A baseline calorimeter stay will determine 24-hour energy needs. Participants will then receive the diet they have been randomized to receive for 6 days and will then have a second calorimeter stay. During this 2nd stay, each participant will continue to receive the diet they were randomized to receive and will achieve a 300 kcal energy deficit through physical activity. The investigators hypothesize that children who receive a 300 kcal energy deficit from the energy expenditure of exercise and receive 3 to 4 servings of dairy products will show greater increases in fat oxidation compared to children who receive a 300 kcal energy expenditure of exercise and receive 1 or fewer servings of dairy products.