A research team at Kaiser Permanente found that good predictors of weight loss were the amount of sleep one got per night and stress levels experienced. They published their findings in March 2011 in the International Journal of Obesity.
Sleep, stress, television viewing, and computer screen time are factors that have been studied and associated with obesity but few have studied whether these factors correlated with weight loss.
About 500 subjects were asked to lose at least 10 pounds over six months and to report levels of insomnia, stress and depression, and to record how much time they slept and spent watching television or using a computer.
Each participant was weighed weekly, advised to keep a daily food diary, reduce caloric intake by 500 calories per day, eat a low-fat, low-sugar diet with lots of fruits and vegetables, and exercise at least 30 minutes, 6 times a week.
They found that those most likely to lose 10 pounds were those with the lowest stress levels and who got more than 6 hours, but less than 8 hours, of sleep per night. Also noted was that these subjects were twice as successful in losing weight as those who reported the highest stress levels and got less than 6 hours of sleep per night.
The research team found that sleep and stress levels were good predictors of weight loss, but depression and screen time were not.
This study suggests that if you want to increase your chances of losing weight reduce your stress level and get adequate sleep.