Photo: Provided by Sherrie Harris

Weighing in at 285 pounds, Sherrie Harris (right) decided to do something about it, so she joined Weight Watchers. After she saw her mom shed 147 pounds, Courtney (left) followed suit, dropping 66 pounds and overhaulling her eating routine. A typical pre-diet day for the two consisted of fast food, fried foods and carb-heavy sides like mac and cheese and mashed potatoes -- and neither paid attention to portion sizes. "Exercise was changing the channels on the remote, or going up the stairs to watch TV in our rooms as we ate M&M's or Cheez-Its," Sherrie tells AOL Health. Read more about their success story and others who got fit together on AOL Health.

Have you lost big? Share you diet success story with That's Fit here.