Lifestyle Health '1000-Lb. Sisters' ' Tammy Slaton Is 15 Lbs. Heavier After Leaving Food Rehab: 'I'm Not Happy About It' At her first weigh-in after leaving rehab, Slaton, her doctor and her brother-in-law are all disappointed to see that she’s gained weight By Julie Mazziotta Julie Mazziotta Julie Mazziotta is the Sports Editor at PEOPLE, covering everything from the NFL to tennis to Simone Biles and Tom Brady. She was previously an Associate Editor for the Health vertical for six years, and prior to joining PEOPLE worked at Health Magazine. When not covering professional athletes, Julie spends her time as a (very) amateur athlete, training for marathons, long bike trips and hikes. People Editorial Guidelines Published on December 3, 2021 12:00PM EST Tammy Slaton's first weigh-in after leaving a food addiction rehab center earlier than planned leaves everyone in the room disappointed. The 1000-Lb. Sisters star, 35, goes to see Dr. Eric Smith, her bariatric surgeon, in this exclusive clip from Monday's episode. Slaton is hopeful that she's lost more weight, but her brother-in-law Chris, who accompanies her to the appointment, has low expectations. "Tammy's not doing what she needs to do," Chris says. "She's in a relationship with a dude that's not got Tammy's best interest at heart." Meanwhile, Slaton notes that she was at 624 lbs. the last time she went for a weigh-in. "I'm hoping that I've lost even more and I'm closer to my 550 goal." Tammy Slaton Decides to Leave Her Food Addiction Rehab After Hitting 631 Lbs.: 'I'm Homesick' But the scale reads 639 lbs., 15 more than the last time. "I gained weight back," she says. "I'm not happy about it. I hate it. I hate it." And Chris is frustrated with Slaton's lack of dedication. "This s---'s unbelievable," he says. "Tammy gained about 15 lbs. than what it was three weeks ago, so it sucks. She's pissing precious time away that she really ain't got." Tammy Slaton. TLC And Smith, meanwhile, says that this was his concern. "What happened is what I was afraid of. Tammy left rehab too soon," he says. Smith had set a goal for Slaton to lose 100 lbs. in rehab, but in the season premiere, she decided to leave early, despite getting down just 60 lbs. "I know I'm supposed to lose 100 lbs., but 60 is a great start," she said at the time. "I've been here long enough, I've seen what to do. I just gotta do it." "I'm homesick. I miss my bed, I miss my family. So, I think I'm ready to go," she added. "I want to try to get the rest of the weight off on my own." 1000-Lb. Sisters' Tammy Slaton Reveals She Has a New Boyfriend: 'He Likes Big Girls' In the weeks since, Slaton's sister Amy convinced her to hire a home nurse to keep her eating habits in check, but she also started dating a guy who "likes big girls." "He's just a supporter," Slaton said. "And he knows very well that I'm on a weight loss journey. And he's okay with it. He's all for me losing weight and getting healthier. No, he don't want me to get under 300, and I'm fine with that."