While one or two cups of coffee can boost mental alertness, drinking more can overstimulate your central nervous system and cause insomnia.
But studies have also found that drinking as few as two small cups of coffee can affect the quality of sleep. Caffeine blocks the action of adenosine, a sleep-inducing brain chemical.
If you have insomnia, cut caffeine eight hours before bedtime. Consume no more than 200 milligrams of caffeine a day, or preferably none.
One eight-ounce cup of regular coffee has 80 to 175 milligrams of caffeine; the same amount of tea has 45 milligrams. Other sources of caffeine include cola, energy drinks, dark chocolate and certain over-the-counter pain relievers (e.g. Midol, Excedrin, Anacin).
There's no question that alcohol can disrupt sleep, causing you to wake up in the middle of the night. It also dehydrates you, which can worsen fatigue the next day.
If you have sleep apnea, drinking alcohol can make your throat muscles relax more than normal, increasing the chance of airways becoming blocked.
If you suffer from insomnia, avoid alcohol for a few weeks to see if your sleep improves. If you do drink, limit your intake to one alcoholic drink a day (e.g. five ounces of wine, 1.5 ounces of sprits, 12 ounces of beer). Drink alcohol with a meal rather than on an empty stomach.
Avoid late-night meals
Eat your evening meal at least three hours before bedtime to prevent digestive upset that can keep you awake.
Research also suggests the more fat you eat at your evening meal, the more likely you are to experience sleep disruptions, so keep your meal lean. If you have heartburn, avoid spicy meals that can trigger symptoms and prevent a good night's sleep.
Stop drinking fluids two hours before bed. This will reduce the likelihood of needing to get up in the night to go to the bathroom.
Eat a bedtime snack
A small carbohydrate-rich snack, such as a glass of skim milk, a small bowl of cereal, a slice of toast, or a piece of fruit provides the brain with tryptophan, an amino acid used to manufacture serotonin. Among its many effects, serotonin helps facilitate sleep.
Lose excess weight
Fat deposits around the upper airway can obstruct breathing during sleep. Losing 10 per cent of your body weight - 22 pounds for a 220-pound man - can greatly reduce the number of sleep apnea episodes a night.
Regular exercise helps you fall asleep faster, promotes weight loss and relieves stress. Exercise at least three hours before bedtime. Working out right before bed can make falling asleep more difficult.
Valerian is one of the most popular and widely studied herbal remedies for short-term treatment of insomnia. It's thought to promote sleep by interacting with certain brain receptors.
The recommended dose of valerian is 400 to 900 milligrams a day taken two hours before bedtime. Several nights to a few weeks may be needed for it to work.
Short-term use of melatonin may also be effective for improving sleep, especially in older adults. The recommended dose is 0.3 to five milligrams at bedtime.
Speak to your pharmacist or health-care provider to see if either supplement is right for you.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.