Restricting calories could improve obstructive sleep apnea and reduce high blood pressure in obese adults, according to a recent study.

People with sleep apnea usually experience pauses in breathing five to 30 times per hour or more while sleeping. It prevents restful sleep and is associated with high blood pressure, arrhythmia (abnormal heart rhythm), stroke and heart failure.

"This study suggests that in obese patients with obstructive sleep apnea, moderate energy restriction can reduce not only body fat but also the severity of obstructive sleep apnea," Marcia R. Klein, co-author of the study and adjunct professor in the Department of Applied Nutrition at Rio de Janero State University in Brazil, said in a statement. "So moderate energy restriction in these patients has the potential to reduce cardiovascular risk.

For the study, the research team conducted a 16-week randomized clinical trial. They analyzed 21 obese people between the ages of 20 and 55 years old with a history of sleep apnea. One group was instructed to reduce their calorie intake by 800 calories per day, while another group continued their current diet.

They found that those in the calorie-restricted group had fewer pauses in breathing during sleep, lower blood pressure, higher levels of oxygen in their blood and a greater reduction in body weight.

"Losing weight was most likely the key to all the benefits observed in the calorie-restricted group," Klein said. "A greater reduction in systolic blood pressure can be explained, at least partially, by the reduction in body weight that was associated with reduction in obstructive sleep apnea severity and sympathetic nervous system activity."

Systolic blood pressure is the top number in a blood pressure reading, which measures the force of the blood in the arteries when the heart is contracted.

The findings were presented at the American Heart Association's High Blood Pressure Research Scientific Sessions 2014.