21 April 2016

Middle-aged men whose diet is high in fat are more likely have sleeping problems than those who eat healthily, according to Australian researchers.

And they are more likely to be sleepy in the daytime.

Fat may affect sleep by altering circadian regulation of hormonal, central nervous and metabolic systems, the University of Adelaide researchers suggest. The circadian clock or circadian rhythm is a built in body clock that regulates our sleep-wake cycle and runs to roughly 24 hours.

“Long-term high fat intake may lead to elevated levels of leptin and decreased levels of ghrelin, which could regulate arousal and wakefulness via orexin,” they write in the journal Nutrients. Leptin and ghrelin are the so-called ‘hunger hormones which regulate appetite and orexin regulates arousal, wakefulness and appetite.

High fat intake was also associated with obstructive sleep apnoea after adjusting for age, waist, lifestyle factors, chronic diseases and medication.

Based on data from more than 1800 men, the 12-month study found the direct effect of BMI on sleep apnoea was about five times stronger than that of fat intake.

Nonetheless, the results suggest a fatty diet has significant implications for sleep, alertness and concentration.

No association was found between carbohydrate or protein intake and excessive daytime sleepiness.

“Poor sleep and feeling sleepy during the day means you have less energy, but this in turn is known to increase people’s cravings for high-fat, high carbohydrate foods, which is then associated with poor sleep outcomes,” says lead author, Yingting Cao, a PhD student at the University of Adelaide.

Last Reviewed: 21/04/2016



Associations between Macronutrient Intake and Obstructive Sleep Apnoea as Well as Self-Reported Sleep Symptoms: Results from a Cohort of Community Dwelling Australian Men