By Wendy Winkler

Sleeping more than nine hours a night has proven to suppress genetic factors that lead to weight gain.

Researchers at the University of Washington in the USA concluded that sleep is vital to people who have inherited tendencies to put on weight.

On the opposite side of the scale, less than seven hours of sleep can be contributed to obesity.

Tired of counting sheep? Here’s a sleeping plan:

Go to sleep when you’re tired

It seems obvious, but do you regularly ignore yawns and think, “I’ll just do this first”?

Get up at the same time each day

This is more important than going to bed at a set time because it’s the time you wake up that resets your body clock to sleep that night.

Keep a sleep diary

Note when you try to go to bed, when you fall asleep and what you eat and drink.

Avoid TV and computers

For at least an hour before you want to sleep.

Get out of bed if you’re awake for more than 15 minutes

You’ve heard this before, but apparently you have to do something aside from TV, texting or going online. D'oh.

Make sure you’re not too hot

Your body heats up during the night, so ditch the second doona. A room temperature of 15-20 degrees is ideal for inducing sleep.

Make sure the room is dark and use earplugs if it’s noisy

Studies show unfamiliar noise during the first and last two hours of sleep can suppress immune function, even if you don’t wake up.

Ignore worrying thoughts about not sleeping

Instead, focus on the fact you’re getting some sleep – even if you don’t know it. A study by the US National Sleep Foundation found a third of the participants thought they’d slept for at least an hour less than their brain-wave activity indicated.