By Tanya Zuckerbrot ... via Fox News

Nothing is worse than tossing and turning all night knowing you’ll be dragging the next day. If you’ve ever experienced insomnia or stayed up way too late, you know the symptoms of sleep deprivation: crankiness, lethargy and grogginess.

When you are overtired, do you tend to feel hungrier or reach easily for sugary, high-fat foods?   You are not alone. Studies show that lack of sleep, poor eating habits and weight problems all go hand in hand.

A recent Harvard study found that people who are sleepy by day are hungrier and more prone to eat high-calorie foods.  When researchers conducted MRIs of their sleep-deprived subjects, they found low activity in the prefrontal cortex area of the brain where critical thinking and decision-making occurs.  It seems people who are sleep deprived may have greater difficulty resisting the wrong foods.

Some theories suggest that lack of sleep causes stress on the body, releasing excess cortisol which not only stimulates hunger, but also slows downs metabolism. When metabolism slows you are more apt to store calories as fat than burn them for energy.

Lack of sleep is known to affect the hormones that control feelings of hunger and fullness. Ghrelin, which is produced in the gastrointestinal tract, stimulates appetite, causing you to feel hungry, while leptin is produced in the fat cells and sends a signal to your brain that you are getting full. Studies have shown that people who are sleep-deprived have lower leptin and elevated ghrelin levels, setting the stage for overeating. Research conducted at the University of Chicago found that people who slept poorly were more inclined to eat sugary, refined carbohydrates.

According to the National Sleep Foundation, 63 percent of American adults don’t get the recommended seven to nine hours of sleep a night.  This suggested sleep time consists of about five 90-minute sleep cycles, each with a deeply restful rapid-eye movement (REM) phase during which more calories are burned than any other time during sleep. Disrupting or missing some REM cycles can lead to unwanted weight gain, and losing sleep night after night is known to have a cumulative effect.

There are many reasons why we lose sleep. One cause may be the foods we eat later in the day. Loading up on refined carbohydrates at dinner and sweets for an evening snack can pack plenty of calories and precipitate a sugar rush that makes it hard to get a restful sleep. Then after you’ve finally dosed off, as that sugar high crashes, your body’s craving for more sugar may be so strong that you actually wake up and go foraging for something sweet.

With summer fast approaching, getting fit for beach weather calls for healthy eating and plenty of quality sleep. Here are some tips for doing both:

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