On a weekly basis, participants will be contacted via telephone or e-mail to discuss with or participate in question-and-answer sessions with the researchers about the effect of the grape powder supplement or any matter regarding the research progress. Participants will self-report physical activity levels each week for 12 weeks. Also, a diet record of 3 days, including 2 weekdays and one weekend day, will be self-recorded by the participant each week for 12 weeks.