Swedish scientists investigating the impact on sleep of a high fat/high sugar diet – also known as a ‘junk food diet’ – have found it is associated with ‘reduced deep sleep quality and changes in some important sleep patterns’.
The researchers from Uppsala University, whose study was published in the journal Obesity, examined the impact on sleep patterns in 15 healthy men who were randomly assigned 2 different diets to follow: either a high-fat/high-sugar diet or a low-fat/low-sugar diet for one week each.
After each diet, researchers recorded participants’ sleep patterns in a laboratory setting using a method called polysomnography (a sleep monitoring technique) which looked at both the duration of sleep, as well as the different stages and patterns of sleep, including things like oscillatory patterns and slow waves.
While the study found duration of sleep was not significantly different between the two diets – as measured by both actigraphy (a method of monitoring sleep using a wearable device) and in-lab polysomnography, the researchers noticed a diet high in fat and sugar was linked to lower levels of certain sleep characteristics during deep sleep – including delta power (a measure of slow brain waves), the ratio of delta to beta waves, and the amplitude of slow waves.
All of these changes suggested quality of deep sleep was reduced on the high-fat/high-sugar diet.
US endocrinologist Dr Florencia Halperin (not involved in this research) told medicalnewstoday.com that evidence has been mounting over the last decade about the ‘relationship between sleep and metabolic disease.
‘Poor sleep adversely affects hormonal and metabolic parameters and increases the risk of weight gain and metabolic disease. At the same time, weight gain increases the risk of sleep disorders such as sleep apnea.’
She noted that ‘while the macro-architecture was not affected, changes in some sleep parameters observed (less relative power in delta frequencies and a lower delta-to-beta ratio) were consistent with a less restorative sleep state, as might be seen in an older population.’
Dr Halperin also noted ‘this is early evidence that a typical unhealthier diet may affect our sleep in very specific ways, and therefore our sleep-regulated health parameters, such as cognition and hormone secretion, which then modulate other effects on our health.’
