Low calorie diet for sleep apnea

Obstructive sleep apnea (OSA) is a common sleep apnea caused by the collapse of the upper airways during sleep. Its characteristics are pauses in breathing whilst sleeping, with every episode (apnea) lasting for around 10 seconds.
Moderate and severe obstructive sleep apnea, that is, 15 or more apneas every hour carries an excess risk of car accidents, death and heart disease . Surprisingly only one study has scrutinised the effects of weight loss on obstructive sleep apnea.
Researchers at the Karolinska Institute in Sweden have studied whether or not treatment with a low energy diet lowers moderate and severe obstructive sleep apnea in obese men.
The study involved 63 obese men (BMI 30-40) aged 30-65 years with moderate to severe obstructive sleep apnea who were being treated with continuous positive airway pressure, that is, a mask designed to help breathing during sleep.
30 men were placed on a liquid very low energy diet for seven weeks to achieve weight loss, followed by a fortnight’s introduction to normal food. The remaining men formed a control group by adhering to their normal diet over the nine weeks.
At the beginning of the study, both groups had a mean apnea hyperpnoea index (AHI) of 37 apneas per hour. At week nine, the diet group had a mean AHI of 12 events per hour compared with 35 events per hour in the control group, the researchers discovered.
In addition, the results highlighted that the diet group lost an average of 18.7 kg in weight in contrast to the 1.1 kg in the control group over the nine-week period. 22 out of 30 patients in the diet group were no longer obese at the end of the study, whereas all the control patients stayed obese.
Furthermore, the researchers discovered that 5 out of 30 patients in the diet group were disease-free by the end of the study, and half had just a mild condition, whereas, all patients in the control group apart from one still had a moderate to severe condition.
The researchers concluded that treatment with a low energy diet improves obstructive sleep apnea in obese men, with the most significant impact on patients with a severe condition.