Denise and Tiffany are identical twins except that Denise weighs 220 lbs. and Tiffany weighs 110 lbs. They both walk on the treadmill with no incline at a speed of 3.5 mph for 30 minutes. If they continue this exercise program five days a week for the next three months while maintaining the same food intake, which of the following statements is correct? (30 seconds)

Denise will consistently lose the same amount every week as will her sister
Tiffany will start losing more weight per week
As they both lose weight, Denise will lose less weight per week as the weeks go by, but Tiffany's rate of weight loss will stay the same
As they both lose weight, both Denise and Tiffany will lose less weight per week
As they both lose weight, both Denise and Tiffany will lose more weight per week