If you're suffering from poor sleep, your diet might not be the first thing you consider changing. But new research shows just how dietary quality and sleep can affect each other. University of Adelaide researchers have found that men who consume diets high in fat are more likely to feel sleepy during the day, to report sleep problems at night and are also more likely to suffer from sleep apnea.
Conducted by Adelaide's Population Research and Outcome Studies unit, the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study looked at the association between fatty diets and sleep in more than 1800 Australian men aged 35 to 80. The results — based on dietary habits over a 12-month period — have been published this month in the journal Nutrients.
"After adjusting for other demographic and lifestyle factors, and chronic diseases," says doctoral student and study author Yingting Cao, "we found that those who consumed the highest fat intake were more likely to experience excessive daytime sleepiness." The impact of impaired alertness and concentration should be of particular concern to workers, Cao says.
Forty-one percent of those who took part in the study reported experiencing daytime sleepiness, while 47% had poor sleep quality at night. In addition, a sleep study among participants who had no previous diagnosis of sleep apnea showed that roughly 54% experienced mild-to-moderate symptoms while 25% showed moderate-to-severe indications of the condition.
"Poor sleep and feeling sleepy during the day means you have less energy," Cao says, "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. So the poor diet-and-sleep pattern can become a vicious cycle."
Cao explains that studies into the effect of varying diet on weight loss rarely take sleeping patterns into account. She says the team hopes their work can help to inform future intervention studies, enabling people to achieve healthy weight loss while also improving their quality of sleep. The relationship between nutrition and sleep is important, she stresses. "The simple message is a commonsense one but we need more people to pay attention to it: we need to eat better; a good sleep the night before is best."