Adam Childers worked as a cook at Boston's Gourmet Pizza. While on duty, he was struck in the back by a heavy freezer door, seriously injuring his lower back. As a result of the injury, Childers suffered from severe lower back, hip, and leg pain. He was treated with pain medication and physical therapy, but his condition worsened over several months. He wanted to have spinal fusion surgery, but the doctors recommended against it. At the time of the injury, Childers was twenty-five years old, six feet tall, and weighed approximately 340 pounds. Due to his age and weight, the surgery was extremely risky. Furthermore, Childers's weight ballooned to 380 pounds in the months after his injury, because he was depressed and inactive. Though he tried to lose weight by adjusting his diet, he failed. A doctor ultimately recommended that Childers undergo lap band or other weight reduction surgery so that either his resulting weight loss would alleviate his pain symptoms or his lowered body weight would allow him safely to have back fusion surgery. Boston's Gourmet Pizza admitted that Childers's back injury was work related and did not dispute that treatment for the injury was covered under the applicable workers' compensation law. It argued, though, that it was not obligated to provide the precursor surgery (i.e., lap band for weight reduction) that would allow Childers to undergo the treatment for his work-related injury. Rather, the employer asserted that Childers's weight problem was a preexisting condition that relieved it of responsibility for Childers's treatment under the workers' compensation law. Is the employer's argument correct?