1 April 2008

Move It & Lose It with Prof Trim

Less sleep, more fat
This month’s story sounds a bit like a contradiction of the ‘move it and lose it’ terms. But lack of sleep causes more problems than just feeling tired the next day. Although the connection has been suspected for some time, several studies have now shown a connection between lack of sleep and increases in body weight. This has been shown to occur early in life, with children as young as five or six having a greater risk of becoming overweight later in life if they sleep less than seven hours a night on a regular basis.


One reason for this might be obvious: The longer you are awake, the more time you have to eat. And given that this time is not likely to be spent being active, the extra energy intake will quickly develop into extra body weight.

More detailed research however has also shown that certain hunger hormones, particularly one called leptin, are increased with extra waking hours. It’s proposed that this goes back to evolution when longer periods of wakefulness were associated with getting more food in lean times. Irrespective of the cause it seems sleep is important – and we’re getting less and less of it with our busy modern lifestyles.

Many of us have trouble sleeping from time to time, especially when we are stressed or have worries. Insomnia is a symptom not a disease. Reducing anxiety and sticking to a day–night routine can improve sleep quality. Suggestions include:

  • Get your bedroom right, it should be cool, dark and quiet. And limit activities to sleeping and sex. No television or dealing with the day’s emails on your laptop.
  • Take time to unwind before bed – whatever it takes: a warm bath, soft music, meditating, a good book. No late night news or sitcoms.
  • Cut down on drinking. Yes a nightcap can be relaxing. It may even help you nod off. But it will more likely produce fragmented, fitful sleep than sweet dreams and sound sleep.
  • Avoid tea, coffee and other caffeinated drinks after four in the afternoon. That includes drinks with guarana.
  • No big meals late at night. Give your full stomach the good two hours it needs to digest food before you dream of turning in.
If your insomnia has persisted for years, see your doctor or contact a sleep disorder clinic.

Dr Garry Egger aka Prof Trim

– Click for more information on Professor Trim.


Anonymous said...

I thought the story of sleep and weight was as much about the hormone ghrelin as much as leptin. Isn't it ghrelin that promotes appetite and leptin that has the opposite effect? The other question is how much the quality of sleep has an effect. If I sleep well for fewer hours what happens to the hormones?

Martina Chippindall
Dietitian / Diabetes Educator
Perth WA

GI Group said...

Hi Martina, We'll pass this on to Prof Trim and post his reply as soon as possible.

GI Group said...

Prof Trim says: 'The answer to this is more complex than may have been implied in the article. Ghrelin and leptin have both been implicated in sleep (or lack of) induced weight loss, but there are also probably many other hormones and other substances involved. You must also consider the behavioural aspects - children, in particular, who are not sleeping are often using computers/electronic games etc. When they do this, they eat out of habit, and eating causes weight gain.

Quality of sleep is also important and when we talk about 'general' sleep patterns, these are based around a normal curve of 7-8 hours sleep a night. However there are many people who manage quite well on much less than 7 hours or much more than 8. And of course, time in bed is no indication of quality of sleep.'