It may not be necessarily diet control or exercise, but if you want to become slim develop a good sleeping habit, suggests a new book after looking at a host of new research.
Sleepless nights significantly disrupt our hormones and metabolism, leaving us much more prone to overeating and weight gain, according to 'The Duvet Diet - Sleep Yourself Slim' written by health journalist Jane Worthington, reported online edition of Daly Mail.
But once you get into healthy sleep habits, she says in the book, you'll find it much easier to control your appetite and lose weight. She quoted several studies including a recent one of more than 6,000 people carried out at Columbia University, America.
People who slept four hours or less per night were 73 percent more likely to be obese than those who slept between seven and nine hours a night, it said. And those who got five hours sleep a night were still 50 percent more likely to be obese.
Other evidence to back up Worthington's theory comes from a series of pioneering studies by the University Libre de Bruxelles and the Department of Medicine at the University of Chicago, Illinois, both of which showed clear links between metabolic changes and sleep deprivation.
In the first study, healthy young men were observed during a 16-day sleep trial. For three of those days the men had eight-hour periods of sleep; for the next six days they slept for just four hours; and for the last seven days they had 12-hour sleep periods.
It was found that at the end of the four-hour nights, the subjects had significantly decreased levels of the hormone leptin.
"Leptin provides our brains with the "stop feeding me - I've stored enough food" signal," explains Worthington. "If the levels of leptin are decreased, the brain starts to tell the body it's hungry when it's not, so this may increase the drive for food intake and, ultimately, contribute to obesity."
The second study compared the glucose tolerance levels of poor sleepers (those who had broken sleep) with normal sleepers.
Glucose tolerance measures your body's ability to deal with excessive sugar in the blood. 'Low' tolerance is a sign that it is not doing this effectively, which could put you at long-term risk of developing diseases such as diabetes.
The glucose tolerance of the poor sleepers was found to be much lower than that of the normal sleepers.
According to the researchers, this suggests too little sleep on a regular basis could push poor sleepers down the slippery slope towards obesity, diabetes and cardiovascular disease.