Getting at least seven hours of sleep every night can help you stick to a weight-loss and exercise routine, a study shows.
Researchers at the University of Pittsburgh enrolled 125 overweight or obese middle-aged adults, mostly women, in a one-year fitness program.
Participants were tasked with following a calorie-restricted diet and increasing their daily physical activity.
Although adherence to the plan declined over time in both groups, scientists found that those who slept better were more likely to eat less and exercise more.
Even the bare minimum of seven hours of sleep a night can help you lose weight, scientists say (stock image)
The Centers for Disease Control and Prevention (CDC) says all adults should get at least seven hours of sleep each night.
But estimates suggest that as many as one in three consistently fail at this level.
Getting too little sleep for just three nights causes a dip in mental and physical health, reducing concentration, mood and even breathing problems.
There is even evidence that someone who doesn’t sit for seven hours a night is more likely to overeat and crave more fatty, salty, and sugary snacks than whole foods.
In the study, nine out of ten participants were female and all had a BMI between 27 and 44, placing them in the overweight and obese categories.
All participants were enrolled in a weight loss program and had data on their sleep and adherence at baseline, at months 6 and 12.
Compliance with the weight loss program was measured by the percentage of group intervention sessions attended; percentage of days when each participant ate between 85 and 115 percent of their recommended daily calories; and change in daily duration of moderate or vigorous physical activity.
Sleep was scored from zero to six, with six being the highest score, based on the sleep factors below.
These were: consistency, satisfaction, alertness, timing, efficiency (time in bed while you are actually asleep), and duration.
Each factor received one score for ‘good’ or zero for ‘bad’.
Sleep was scored using patient questionnaires, a sleep diary, and seven-day measurements from a wrist-worn device that recorded sleep, wakefulness, and rest.
Participants’ caloric intake was tracked by entering their expenditure into a mobile phone app, and physical activity was measured using an accelerometer worn on the wrist. These measurements were also taken at the start of the plan and after six months and 12 months after the start of the plan.
The results were then analyzed comparing participants who had slept and those who had not slept enough.
During the study period, 79 percent of participants attended group sessions for the first six months, but this dropped to 62 percent over the following six months.
Caloric goals were met on 36 percent of days in the first six months, but on 21 percent in the following six months.
And total moderate-to-vigorous daily activity time increased by 8.7 minutes in the first six months, but then dropped by 3.7 minutes in the second six months.
Analysis showed that participants who got enough sleep were more likely to stick to the plan.
They were also more likely to attend group sessions, stick to diet, and meet their physical activity goals.
The researchers did not provide data on the amount of weight lost by either group.
No information was given about what fitness plan they were following either.
Dr. Christopher Kline, an expert in sleep at the University of Pittsburgh, Pennsylvania, said: “Focus on getting a good night’s sleep — seven to nine a.m. with a regular wake-up time along with waking up refreshed and alert throughout the day — can be an important behavior that helps people stick to their physical activity and dietary modification goals.
“A previous study of ours reported that better sleep health was associated with significantly greater body weight and fat loss in participants in a one-year behavioral weight loss program.”
He added: ‘We hypothesized that sleep would be associated with lifestyle modification; however, we did not expect that there would be an association between sleep health and all three of our measures of lifestyle adjustment.
“While we did not intervene in sleep health in this study, these results suggest that optimizing sleep may lead to better lifestyle compliance.”
The study will be presented today at the American Heart Association’s 2023 Epidemiology, Prevention, Lifestyle and Cardiometabolic Health Scientific Sessions in Boston, Massachusetts.
