Patients with obstructive sleep apnea could benefit from following a low energy diet to lose weight, finds research published on

Approximately 60% to 70% of patients with sleep apnea are either overweight or obese. Previous studies in other patient groups have concluded that losing weight can improve the condition.

The authors, led by Kari Johansson from the Karolinska Institute in Stockholm, investigated whether a low energy diet followed by counseling to keep weight under control benefited patients with sleep apnea.

The study follows a previous trial by the same authors, published in the British Medical Journal in 2009, that investigated the effects of a very low energy diet for 9 weeks. The most recent study looks at the longer term effects of weight maintenance over 1 year.

The study included 63 men between 30 and 65 years of age who had moderate to severe obstructive sleep apnea. The participants had a body mass index (BMI) range of 30-40.

Of the 63 patients, 58 followed a very low energy diet for 9 weeks and then started a 1-year weight maintenance program (this included counseling and advice about nutrition and exercise). The very low energy diet was based on the Cambridge weight plan.

The results show that patients who lost weight after 9 weeks on the low energy diet maintained the loss after a year, and this had a positive effect on their sleep apnea. For instance, at 1 year, 48% of patients no longer required CPAP and 10% had total remission of obstructive sleep apnea.

Patients who had severe forms of the disease at the beginning of the study had larger improvement than those with moderate disease, says the study. The authors also found that patients who lost the most weight improved the most.