So you're eating right and exercising regularly as part of your weight-loss plan -- but are you getting your ZZs?

A new commentary from researchers at Laval University, Quebec, reveals just how big of an effect sleep has on weight -- and weight gain -- and goes into what research shows the link between the two.

"The solution is not as simple as 'eat less, move more, sleep more,'" the researchers wrote in the commentary, published in the Canadian Medical Association Journal. "However, an accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity."

In one of the studies cited in the commentary, study participants decreased the amount of calories they consumed for two weeks, and got either 5.5 hours of sleep a night, or 8.5 hours of sleep a night. By the end of the study period, the ones who got 5.5 hours of sleep a night lost less body fat than those who got 8.5 hours.

And in another study explored in the commentary, 123 overweight or obese adults went on a calorie-restricted diet for 17 weeks. Just like the other study, the amount of sleep they got was linked with how much weight they actually lost by the end of the study period.

The researchers said there should be further studies to see what activities people do during their waking hours -- like watching TV in the morning -- that could instead be spent sleeping.

"New studies provide evidence that insufficient sleep enhances hedonic stimulus processing in the brain underlying the drive to consume food; thus, insufficient sleep results in increased food intake," the researchers wrote in the commentary.

Along these lines, a recent study presented at a meeting of the American Heart Association earlier this year showed that sleep deprivation could spur a person to eat more. HuffPost's Catherine Pearson reported that one group in the study, who were only permitted to get two-thirds their normal amount of sleep a night, ate more than 500 more calories each day compared with those in the other group in the study who were able to get full nights' sleep.

And sleep may not just be linked with weight by potentially increasing the urge to eat -- another study, published earlier this year in the journal SLEEP, showed that sleep could also impact our genes' influence on weight.

"The longer you sleep, the less important genetics become in determining what you weigh," study researcher Dr. Nathaniel Watson, co-director of the University of Washington Sleep Disorders Center, earlier explained to HuffPost. "Does this mean you can sleep yourself thin? Probably not. But you can sleep yourself to a point where environmental factors, like diet and activity, are more important in determining your body weight than genetics."

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