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

Substrate Oxidation in Children in Response to Exercise With 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.

The study objective was to conduct a randomized clinical trial comparing enhanced levels of dairy consumption to lower levels of dairy consumption during an energy deficit resulting from 300 kcal of exercise. Participants were 24 sedentary and overweight boys, 13-15 years of age and girls, 12 to 14 years of age, and consuming 1 or fewer servings of dairy and less than 600 mg calcium per day at baseline. Participants were randomly assigned to either higher or lower dairy for 6 days and then crossed over to the opposite treatment subsequent to 2 weeks of wash out. The investigators provided all meals and snacks for the participants during the higher and lower dairy conditions. During the wash out period, participants were instructed to consume their normal diet as assessed at baseline which consisted of 1 or fewer servings of dairy and less than 600 mg calcium. Participants stayed in the calorimeter at baseline, day 7, and day 28 (end of study), after crossover. The calorimeter measured substrate oxidation under the condition of a 300 kcal energy deficit due to exercise.

Inclusion Criteria:

• Must be overweight
• and 10-13 years old
• currently consuming 1 or fewer servings of dairy
• less than 600 mg calcium per day

Exclusion Criteria:

• not meeting the above criteria
• must be present for duration of the study