New research out today suggests that changes in sleep
routine can cause you to gain weight. Sleeping just one hour less a
night will lead to you eating an extra 200 calories the next day -
the equivalent of a bagel.
Penn State University recently
conducted a study of 342 teenagers who said they slept for seven
hours a night. The teenagers who took part in the study had an
average age of 17 and wore actigraph bracelets, which measured
their cycles of activity and rest over seven days to estimate how
long they slept each night.
The participants answered a food
frequency questionnaire to see how many calories and snacks, and
how much protein, fat, and carbohydrates they regularly consumed in
the previous year. Researchers then analysed the relationships
between sleep duration, day-to-day sleep variations and food
intake. The results were adjusted for age, sex, race, and body mass
When the amount of time teenagers
slept varied by just an hour - either less or more - they ate,
on average, an extra 201 calories per day. They also consumed about
6g more total fat - the same as a teaspoon of butter or a milk
chocolate truffle - and 32g more carbohydrates the day after - the
equivalent of 100g of spaghetti. Disrupted sleep was also linked
with a 60 per cent higher chance of night-time snacking on school
nights, and 100 per cent higher chance of night-time munching on
Researchers say one possible
explanation for the effect of changes to sleep may be that getting
less sleep may make a teenager more sedentary the next day and so
they become a 'couch potato' who snack in front of the telly.
Another possibility is that shifts in sleep patterns result in a
hormonal imbalance, causing teenagers to eat more.
Study lead author Fan He, of Penn
State University College of Medicine, said: 'According to the data
from our study, it's not how long you sleep that
matters. 'It's about day-to-day variations in how long you
sleep. It may be more important to have a regular sleep pattern
than to sleep longer one day and shorter on another.