Amy and Tammy Slaton joined 1000-lb Sisters with the shared goal of losing weight, but over the course of the sisters' few years on reality TV, only Amy has been successful in making her fitness dreams a reality. Although both Amy and Tammy suffer from food addictions and come from the same childhood trauma, different factors in the Slaton siblings' lives have resulted in the pair's disparate weight loss progress. From Amy's family aspirations to Tammy's struggles with her mental health, here's why Amy Slaton's lost weight and Tammy hasn't in 1000-lb Sisters.

When they first signed on to star in 1000-lb Sisters season 1, Amy and Tammy's main mission was to lose enough weight to qualify for bariatric surgery. The sisters were in their 30s and knew that if they didn't drop a dramatic amount of pounds quickly, their lives could be cut short. Even though it has been a struggle for both of the siblings to combat their food addictions throughout their weight loss quests in 1000-lb Sisters, Amy has been more effective in achieving her health aspirations. While some viewers think this is simply the result of Tammy's laziness, other factors explain why Amy Slaton's lost weight and Tammy hasn't in 1000-lb Sisters.

Related: 1000-Lb Sisters: Why Tammy Slaton May Not Need Her Trach Anymore

At the end of 1000-lb Sisters season 1, Amy had lost enough weight to qualify for her gastric bypass operation. This allowed Amy Slaton to lose over 100 pounds in a matter of months and fast-track her journey to leading a healthy life. Conversely, Tammy has not come close to losing enough weight to get bariatric surgery. Regrettably, Tammy gained weight in 1000-lb Sisters seasons 2 and 3, and is currently in a rehabilitation center recovering from her latest health complication. One reason why Amy and Tammy have been on diverging fitness paths since 1000-lb Sisters season 1 is their contrasting motivations. On top of wanting to extend her lifespan, Amy shared that she was driven to see her weight loss journey through because she wanted to be a mother. Amy knew it would be safer if she didn't get pregnant until she lost a considerable amount of weight.

Tammy and Amy Slaton laughing in 1000-lb Sisters

Where Amy was driven to lose weight by her family aspirations, Tammy Slaton hasn't shared that she has any ulterior motives for following through with her health endeavor. If Tammy had a husband and wanted to be a mother, she might have been galvanized to lose weight as Amy had in 1000-lb Sisters season 1. Additionally, Tammy suffers from depression, which has certainly made it more challenging for the older Slaton sister to stay on top of her weight loss journey. Tammy has shared that she has even considered ending her life, which explains Tammy's self-destructive behavior that has led to her gaining weight back after making months of progress. As far as 1000-lb Sisters fans know, Amy does not struggle with depression, which might explain why she was able to make the tremendous progress in her weight loss venture that Tammy could not.

Amy and Tammy both endured harrowing food addictions, but Tammy Slaton has trailed her younger sister when it comes to burning pounds in 1000-lb Sisters. Despite their shared background, Amy Slaton's lost weight and Tammy hasn't because the pair have different motivating factors and obstacles in their way. Hopefully, Tammy can find something to inspire her to lose weight in the upcoming 1000-lb Sisters seasons.

Next: 1000-Lb Sisters: Why Amy's Instagram Might Show Weight Loss Failure