Sleep and Nutrition

A number of studies have found a connection between shorter sleep durations and increased risk of obesity (and diabetes), especially in women. Some have even gone into detail showing that short sleepers were more likely to show abnormalities in hormones that control hunger and satiety, which may partly explain this.

However, there is one major part of this equation that has not been looked at until now: diet.

A recent study published in the journal Sleep Medicine details some of my recent work exploring relationships between habitual sleep and health. This study examined nutritional profiles from ~450 women and compared the dietary data to a number of sleep-related variables. We studied both subjective sleep (measured with sleep diary) and objective sleep (measured with actigraphy). We looked at both nighttime sleep and daytime naps. What we found was surprising.

Basically, our study found two things:

1. There was a significant relationship between less sleep (verified objectively) and more intake of fat. It didn't matter which kind of fat -- all fats were associated with less sleep.

2. There was an even stronger relationship between more reports of napping (but not actual naps verified by objective methods) with fat intake, as well as with intake of nutrients found in meat. We think that since this relationship was with subjective but not objective naps, this could mean that people who eat more fat and meat are experiencing more sleepiness, even if they are actually sleeping less.

What was especially interesting about this pattern was that this controlled for age (not just one age group driving results), socioeconomic status (not just poorer people eating worse and sleeping worse), BMI (this was independent of weight), total gram amount eaten (it wasn't just that they were eating more), and exercise (it wasn't just that they were less active).

Also of note, there was NO relationship with intake of carbohydrates, even though previous data suggests that sleep-deprived people crave more carbohydrates.

Since these findings were correlational, we can't determine whether the short sleep (or sleepiness) caused more fat and meat intake or eating fat and meat makes you sleep less (and feel sleepier).

However, we conclude that less sleep is associated with eating more fat -- independent of the relationship with obesity. Also, eating more fat (and meat) was associated with feeling more sleepy.

See more in PUBLICATIONS.