Fatty diet linked to daytime sleepiness

Men who consume diets high in fat are more likely to feel sleepy during the day, says a new study.

"This has significant implications for alertness and concentration, which would be of particular concern to workers," says study author and University of Adelaide PhD student Yingting Cao.

The results - based on data of more than 1800 Australian men aged 35-80, including their dietary habits over a 12-month period - are published in the journal Nutrients.

The researchers found those who consumed the highest fat intake over the year were more likely to experience excessive daytime sleepiness.

They also were more likely to report night sleep problems and suffer from sleep apnoea.

"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," Ms Cao said.

"So the poor diet-and-sleep pattern can become a vicious cycle."

Men could prevent daytime sleepiness by eating a healthy low-fat diet, she added.