A variety of studies suggest that getting at least seven hours' sleep every night can significantly improve the chance of losing weight while on a diet.
There is a growing body of evidence that a lack of sleep enhances hunger signals in the brain and increases levels of hormones which affect our appetite, causing us to eat more.
Writing in the Canadian Medical Association Journal, researchers said sleeping habits ought to be addressed along with diet and physical exercise in programmes designed to help obese people lose weight.
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In one recent experiment, they found that people who shifted their sleeping pattern from less than six hours to between seven and eight hours a night put on 2.4kg less weight over a six-year period.
A shorter 17-week study of 123 overweight and obese people showed that people who slept for longer and had a higher quality of sleep were more likely to become slimmer while on a diet.
In another recent study by a separate team, participants were allowed to sleep for either five and a half or eight and a half hours each night for two weeks, while eating a low-fat diet.
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The experiment showed that the lower amount of sleep resulted in stress which caused participants to burn off muscle while storing their body fat.
Compared with those who slept for eight and a half hours each night, the sleep-deprived group lost 55 per cent less body fat and 60 per cent more muscle over the two week period.
The researchers, from the Eastern Ontario Research Institute and Laval University in Quebec, wrote: "An accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity.
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"Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity."
Further research should identify the causes which prevent us getting a full night's rest, such as watching television in the evening, they added.
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