a single night leads to an unintentional ingestion of an extra
400 to 500 calories the following day, and those additional
calories almost always come from carbs. Multiply this by a
few nights, and you’ve got yourself a spare tire in a matter
of weeks. Already overweight? Same rules apply: you are
seriously hurting your chances of dropping extra weight
when sleep deprived.
Ghrelin: The Hunger Hormone
Another hormone affected by sleep is ghrelin. Secreted
by the stomach, ghrelin tells your brain when it’s time to be
hungry. Your ghrelin level increases just before meals or
when the stomach is empty and decreases after meals or
when the stomach is stretched. This hormone can also
impact your behavior: when mice and humans are injected
with ghrelin, the number of meals consumed increases.
Ghrelin surges with just a single night of sleep debt.^13
This may be why one night of sleep deprivation will
provoke, on average, an excess intake of 400 to 500
calories that day, mostly from carbohydrates, coinciding
with increased inflammation, high blood pressure, and
cognitive problems.
Aside from getting more sleep, how can we make
ghrelin work for us? Eating fewer (but larger) meals
throughout the day trains your body to produce less of the
hormone. Science has now revealed that the advice to eat
small, frequent meals to “stoke the metabolic flame” is
bunk: metabolic chamber studies—when volunteers live in a