The Slatons are larger-than-life sisters who have always relied on each other and food for support; Amy, age 31, is desperate to have children, but hasn't been able to due to her weight; Tammy, age 32, is one step away from being bedridden.

Amy and Tammy go to Atlanta to meet Dr. Procter to discuss weight loss surgery; Dr. Procter gives Tammy a weight loss goal before he can approve her for surgery; the dietician has more bad news for Amy.

Amy and Tammy eagerly begin their weight loss journey; sticking to their diets is a matter of life or death but proves to be a real struggle; the pressure to reach their goals culminates in a huge fight that threatens their diets and relationship.

After a stressful first month of dieting, the sisters head back to Atlanta for their one-month check in with Dr. Procter to find out if they are on the right path to their weight goals; the results force Amy to make a difficult decision.

Amy decides to have a real wedding ceremony because if she gets approved for surgery, she's afraid she may not survive; after the wedding, the sisters head to Atlanta hoping for a life-changing final weigh-in.

Amy undergoes gastric bypass surgery to change her life but endangers herself by not sticking to the post-op diet; Tammy seeks support from her love interest, Jerry.