Fans of 1000-lb Sisters have noticed the drastic decline in Tammy Slaton's attitude toward her weight loss goals and her family. Bordering on abusive, Tammy's incessant bullying and manipulation has put her at odds with viewers and family members alike. Now the lone Slaton sibling in the race to receive bariatric surgery, here's why Chris' recent surgery is fueling Tammy's out-of-control lifestyle.

Tammy began the series as an upbeat personality on a weight loss journey with her sister and closest friend, Amy. While Amy successfully achieved her goals and went on to have surgery and even start a family with husband, Michael, Tammy stalled and has had a difficult time supporting her sisters success in the wake of her own failure to thrive. Tammy's big brother Chris Combs has had his own difficulties reaching his weight loss goals over the years, but now he's surpassed Tammy, leaving the star alone on the journey.

Related: 1000-Lb Sisters: Why Tammy's Using Her Weight To Control Her Family

Tammy's car ride with Chris was an awkward experience to witness, as her curt replies to his small talk served as a sure indicator that Tammy was in a foul mood. After arriving at the appointment and facing the inevitable, that Tammy had once again failed to reach even the smallest goal, Chris was approved for his surgery, making him the last Slaton sibling to receive bariatric surgery. Tammy, who was already having difficulties accepting all the recent changes in her life, seemed to resolve to self destruction after the news, taking on an apathetic attitude in contrast to Chris' nervous excitement.

Tammy Slaton in 1000-lb Sisters

Soon after the surgery, the infamous family vacation occurred, and Tammy's attitude toward the family was outrageously spiteful. Tammy has said multiple times in the series that she was frightened she may not live past 35, the age she just turned this past season. She's recently stated that she "missed out" on the partying lifestyle when she was younger due to her depression, and was finally ready to experience that way of life. However, with all the recent changes in her life, audiences and family members have begun to speculate that her overindulgence is just another addiction to help numb her chaotic emotional and mental state, and ruining what good health she has left.

Tammy's mother, Darlene, bet against the star in the beginning of the series stating that the star would "chicken out" before receiving surgery. Those words have come back to haunt Tammy time and time again. With Amy successfully living her life and moving on from her responsibility to Tammy, and older sister Amanda having already received the surgery prior to the series, Chris was the only sibling still having trouble getting his weight problems under control.

Chris has been willing to tolerate Tammy's bad attitude and obvious jealousy of her siblings success out of some degree of solidarity with her. However, now that he too has accomplished his hard-fought goals, his patience with her may have reached the limit. Tammy's lifelong struggles with loneliness and depression have always motivated her bad habits. That's now coupled with bitter resentment as the 1000-lb Sisters star watches the last of her siblings to cross the finish line without her.

Next: Sister Wives: All Signs The Brown's Were Imploding During The Pandemic