There may be an alternative to mechanical intervention when treating sleep apnea, a study at the Karolinska Institute in Stockholm discovered. For the first time, high-quality evidence that “moderate-severe obstructive sleep apnea can be treated with weight loss” has come to light, according to BMJ.

During a 9-week study, 30 obese men were placed on a very low-calorie liquid diet (while another 31 were a control group and ate normally). These men had an average apnea-hypopnea index (AHI) of 37, which is regarded as severe obstructive sleep apnea and means that they averaged 37 incidents of either stopped breathing or shallow breathing per hour of sleep. Following a 7-week, 440-kcal liquid regimen, and then a 2-week gradual reintroduction to normal food, the average AHI among the non-control group had dropped to 12, which is considered mild sleep apnea.

Other findings from the study showed that men on the diet lost an average of 41 pounds over 7 weeks and showed an average drop in their Body Mass Index (BMI) of 5.7 points. In addition, 22 of the 30 subjects were no longer obese, and 5 of them had an AHI of less than 5, which is considered normal, or disease-free.

The study’s main limitation, said Kari Johansson, PhD candidate at Karolinska, was that its short length made long-term effects difficult to determine.