The Fat Trap

For 15 years, Joseph Proietto has been helping people lose weight. When these obese patients arrive at his weight-loss clinic in Australia, they are determined to slim down. And most of the time, he says, they do just that, sticking to the clinic’s program and dropping excess pounds. But then, almost without exception, the weight begins to creep back. In a matter of months or years, the entire effort has come undone, and the patient is fat again. “It has always seemed strange to me,” says Proietto, who is a physician at the University of Melbourne. “These are people who are very motivated to lose weight, who achieve weight loss most of the time without too much trouble and yet, inevitably, gradually, they regain the weight.”

Anyone who has ever dieted knows that lost pounds often return, and most of us assume the reason is a lack of discipline or a failure of willpower. But Proietto suspected that there was more to it, and he decided to take a closer look at the biological state of the body after weight loss.

Beginning in 2009, he and his team recruited 50 obese men and women. The men weighed an average of 233 pounds; the women weighed about 200 pounds. Although some people dropped out of the study, most of the patients stuck with the extreme low-calorie diet, which consisted of special shakes called Optifast and two cups of low-starch vegetables, totaling just 500 to 550 calories a day for eight weeks. Ten weeks in, the dieters lost an average of 30 pounds.

Sleep More, Weigh Less

Sleep More, Weigh Less

It's true: Being short on sleep can really affect your weight. While you weren't sleeping, your body cooked up a perfect recipe for weight gain.

When you’re short on sleep, it’s easy to lean on a large latte to get moving. You might be tempted to skip exercise (too tired), get takeout for dinner, and then turn in late because you’re uncomfortably full.

If this cascade of events happens a few times each year, no problem. Trouble is, nearly two-thirds of Americans aren't getting enough sleep during a typical week Yet experts agree that getting enough shut-eye is as important to health, well-being, and your weight as diet and exercise

Your Sleepy Brain

Skimping on sleep sets your brain up to make bad decisions. It dulls activity in the brain’s frontal lobe, the locus of decision-making and impulse control.

So it’s a little like being drunk. You don’t have the mental clarity to make good decisions.

Plus, when you’re overtired, your brain's reward centers rev up, looking for something that feels good. So while you might be able to squash comfort food cravings when you’re well-rested, your sleep-deprived brain may have trouble saying no to a second slice of cake.

Research tells the story. A study in the American Journal of Clinical Nutrition found that when people were starved of sleep, late-night snacking increased, and they were more likely to choose high-carb snacks.

A second study found that sleeping too little prompts people to eat bigger portions of all foods, increasing weight gain. And in a review of 18 studies, researchers found that a lack of sleep led to increased cravings for energy-dense, high-carbohydrate foods.

Add it all together, and a sleepy brain appears to crave junk food while also lacking the impulse control to say no.

Hunger Hormones

Sleep is like nutrition for the brain. Most people need between 7 and 9 hours each night. Get less than that, and your body will react in ways that lead even the most determined dieter straight to Ben & Jerry’s.

Why? Because insufficient sleep impacts your hunger and fullness hormones, including two called ghrelin and leptin.

Ghrelin signals your brain that it’s time to eat. When you’re sleep-deprived, your body makes more ghrelin.

Leptin, on the other hand, cues your brain to put the fork down. When you’re not getting enough sleep, leptin levels plummet, signaling your brain to eat more food.

Put the two together, and it’s no wonder sleep deprivation leads to overeating and extra pounds.

Then there’s the cortisol spike that comes from too little sleep. This stress hormone signals your body to conserve energy to fuel your waking hours.

Source:- http://www.webmd.com/diet/sleep-and-weight-loss