Pamela A. Popper, Ph.D., N.D.

Wellness Forum Health

Diet affects almost all human function, so it is not surprising to find that diet affects the quality of your sleep. Researchers say that a diet high in saturated fat and sugar results in lighter and less restorative sleep, while more fiber and less fat and sugar improve sleep quality.

Twenty-six normal weight adults without sleep disorders were enrolled in study that involved spending five nights in a sleep lab. The subjects spent nine hours in bed each night, from 10:00PM to 7:00AM, during which they were monitored with polysomnography. For the first four days, subjects ate a controlled diet, and on the fifth day they could eat whatever they wanted.

While the duration of sleep was not different with the different diets, the quality of the sleep differed between the days when the controlled diet was consumed vs when the subjects could have anything they wanted. On the fifth night, it took longer to get to sleep and there was less deep, slow-wave sleep.

Higher fiber intake was associated with less stage one or light sleep, and more slow-wave or deep sleep. More saturated fat intake resulted in less slow-wave sleep, and higher intake of sugar was associated with more arousals.

The original purpose of the study was to see if sleep quality was related to obesity. During this phase of the study, participants were limited to four hours of sleep per night and then their food intake was analyzed in response to shorter and longer sleep sessions. The participants tended to overeat when they were sleep-deprived, and were particularly prone to eat too much fat. The researchers then wanted to see if the reverse was true – did eating fat affect sleep quality? The answer was “yes.”

Lead researcher Marie-Pierre St.-Onge, Ph.D., said the combination of short sleep sessions and poor diet result in a vicious cycle in which short sleep results in eating more fat and sugar, which then causes poor sleep, which then increases the intake of fat and sugar. None of the adults in this study had a sleeping disorder, and yet the effect was profound.

While the study did not seek to identify a mechanism of action, St.-Onge stated that a heightened awareness of the reward value of food accompanies sleep deprivation, and also that decision-making capacity is reduced by sleep deprivation.

The researchers stated that more research is needed, but that prescribing diet-based therapies for sleep disorders might be warranted.

St.-Onge M, Roberts A, Shecter A, Choudhury A. “Fiber and Saturated Fat Are Associated with Sleep Arousals and Slow Wave Sleep.” J Clin Sleep Med 2016;12(1):19–24.

Sue Hughes “Healthy Diet May Improve Sleep Quality.”

Medscape January 22, 2016