The Australian Medical Association Limited and state AMA entities comply with the Privacy Act 1988. Please refer to the AMA Privacy Policy to understand our commitment to you and information on how we store and protect your data.



15 Nov 2019

High intakes of saturated fats and carbohydrates increase the risk of excessive daytime sleepiness, according to a study that has sought to understand the condition.

Excessive daytime sleepiness affects about 15 per cent of Australia’s general population and is associated with health and societal consequences – from increased risk of work-related errors and injuries, to cardiovascular diseases and mortality.

Flinders University researcher Dr Yohannes Adama Melaku said the findings had been inspired by diet-related excessive feeling of sleepiness observations that had previously been identified in much smaller studies.

 This research is part of the expansive North West Adelaide Health Study (NWAHS), which has examined data of 4,033 participants aged 18 to 90 years between 1999-2000 and 2018.

“We saw a great opportunity to examine daytime sleepiness outcomes within a much larger sample size,” Dr Melaku said.

 “It was taking a theory out of the laboratory and seeing if it applied in the general population. And we found that it has.

“Unique to this study, we applied advance methods to investigate the substitution effect of one macronutrient by other macronutrients. In other words, we looked at the effect of changing nutrients in the diet without changing the amount of calories consumed, allowing us to demystify the interplay and complex interaction among macronutrients in predicting daytime sleepiness.”

The study shows that saturated fat intake was positively associated with feeling sleepy during the day, with a modest similar association of carbohydrate intake.

Professor Adams, who is Medical Director of the Adelaide Institute for Sleep Health at Flinders University, said more research needs to be done about whether replacing high saturated fats and carbohydrates with more protein in a diet will remedy excessive daytime sleepiness problems in patients.

“This study highlights the important role of diet in predicting risk of daytime sleepiness among adults,” Prof Adams said.

“People who have sleep related disorders (such as Obstructive Sleep Apnea patients) and disturbed circadian rhythm, such as shift-workers, could benefit from dietary interventions to alleviate excessive daytime sleepiness.

“In addition, the findings of this study have significant implications for alertness and concentration, which would be of particular concern to workers in certain industries.

“Our findings can assist in the design of trials involving substitution of food types in populations with excessive daytime sleepiness.”

The paper, Association between macronutrient intake and excessive daytime sleepiness: an iso-caloric substitution analysis from the North West Adelaide Health Study, has been published in the journal Nutrients.


Published: 15 Nov 2019