The optimal amount of sleep is unique to each individual. To determine how much sleep you need, you have to find out how much time it takes for you to wake up feeling refreshed without needing an alarm clock. Studies show that humans need 6–10 hours of sleep each night, which is why you’ve most likely heard the recommendation for an average of 8 hours each night.

However, some people can function well with 6 hours of sleep while other people need all 10. According to recent research, dipping below the 6-hour mark impairs cognitive functioning and increases symptoms of stress for just about everyone, so it is recommended that you always get at least 6 hours of quality sleep each night.

SHARP Science: Sleep Your Cravings Away. Brain scans show that our desire for junk food increases when we are sleep-deprived. Many studies have shown an increase in overall food consumption, most likely in a response to an energy-deficit. Using fMRI scans, researchers from New York’s St. Luke’s Roosevelt Hospital Center and Columbia University detected higher activity in reward centers in the sleep deprived brains that were less active when participants had adequate sleep, proving a neurological basis to the quest for high calorie, high fat food.

 How Do You Know If You’re Not Getting Enough Sleep?

 If any of the following applies to you, you probably need to get more shut-eye:

1. You’re dependent on an alarm clock. If you’re getting enough sleep, you should be able to wake up on time without a morning alarm.

2. You’re driving drowsy. Falling asleep at the wheel is a sure sign that you are too tired. It’s also incredibly dangerous, as drowsy driving is a common cause of deadly auto accidents.

3. You’re attached to the coffee pot. It’s fine to start with a cup of coffee, but you shouldn’t have to rely on coffee (or other energy drinks) to stay awake throughout the entire day.

4. You make a lot of mistakes. It’s harder to focus and concentrate when you are tired. You’re more easily distracted and less likely to catch and fix errors.

5. You’re forgetful. Sleep loss may explain why you have a hard time remembering things, since sleep deprivation hinders short-term memory.

6. You’re snippy and irritable. Being tired can have a negative effect on your moods. It makes you more likely to feel depressed, anxious, and frustrated.

7. You’re frequently sick. Your immune system is not at full strength without sleep, thereby making it harder for your body to fight illness.


Contributed by Heidi Hanna, PhD, FAIS- from her most recent book,  The SHARP Solution.