If you're cutting back on sleep time to hit the gym, you might do better to stay in bed.  "Sleep deprivation can cause hormonal changes that contribute to weight struggles, tummy fat and declining muscle mass." says Eileen Silva, Ph.D., N.D., co-author of 'A Healthier You.'

Here's why:  During sleep, fat cells in the body produce an appetite-regulating hormone called leptin, which tells your brain when it's time to stop eating.  Lose enough sleep--and miss out on producing leptin--and you'll experience instense carb cravings and eventually the dreaded ab flab.

Here's how to make sleep your weight-loss weapon:

Establish a Pattern - Go to bed and wake up at the same time each day--even on weekends.  And invest in a comfortable mattress and pillows.  Quality sleep is worth a few extra dollars, particularly since it's likely to increase your productivity during daylight hours.

Wear Yourself Out - "Physical acitivity promotes the deep, restorative states of sleep," says Silva.  "And if you're well-rested, you'll have more energy to work out."  But unless you're doing yoga or medication, try to squeeze exercise into the early part of your day.  High-intensity workouts just beflore bedtime can release endorphins, which make it difficult to sleep.

Make a Five O'Clock Rule - Avoid alcohol, tobacco and caffeine (chocolate, coffee and colas) after 5PM.  Even though alcohol is a depressant, it interferes with the quality of sleep.  As stimulants, caffeine and nicotine not only impact peaceful slumber, but they can prevent you from falling asleep altogether.

Chill - Stress is one of the biggest obstacles to restful slumber.  Use a journal to get out all of your anxious thoughts, listen to soothing music, read a novel, meditate or take a warm bath before bed.  And don't try to go to bed hungry.  Eating a light snack may help promote the onset of sleep.  Go for graham crackers a a glass of skim milk.  "Dairy snacks like cheese and milk are high in the amino acid tryptophan, a natural sleep aid," says Silva.
                                                                 -From diets.aol.com