According to preliminary research presented at the American Heart Association’s Epidemiology, Prevention, Lifestyle & Cardiometabolic Health Scientific Sessions 2023, people who reported getting regular, uninterrupted sleep did better at sticking to their exercise and diet plans while attempting to lose weight.
The symposium, which will take place in Boston from February 28 to March 3, 2023, will feature the most recent research on population-based health and wellness, as well as its effects on lifestyle and cardiometabolic health.
“Focusing on obtaining good sleep seven to nine hours at night with a regular wake time along with waking refreshed and being alert throughout the day may be an important behavior that helps people stick with their physical activity and dietary modification goals,” said Christopher E. Kline, Ph.D., an associate professor in the department of health and human development at the University of Pittsburgh. “A previous study of ours reported that better sleep health was associated with a significantly greater loss of body weight and fat among participants in a year-long, behavioral weight loss program.”
The researchers looked at whether people’s ability to stick to the various lifestyle changes suggested in a 12-month weight loss program was associated with how well they slept. The weight-loss program included 125 adults (average age of 50 years, 91% female, 81% white) who met criteria for overweight or obesity (body mass index of 27-44) without any medical conditions requiring medical supervision of their diet or physical activity.
Through patient questionnaires, a sleep journal, and seven-day readings from a wrist-worn device that recorded sleep, waking activity, and rest, sleep habits were assessed at the start of the program, at 6 months, and at 12 months. These measures were used to score each participant as “good” or “poor” on six measures of sleep: regularity; satisfaction; alertness; timing; efficiency (the percentage of time spent in bed when actually asleep); and duration.
Each participant received a composite sleep health score ranging from 0 to 6, with one point awarded for each “good” indicator of sleep health. Higher scores denoted higher levels of sleep health.
There are over 100 studies linking sleep to weight gain and obesity, but this was a great example showing how sleep isn’t just tied to weight itself, it’s tied to the things we’re doing to help manage our own weight. This could be because sleep impacts the things that drive hunger and cravings, your metabolism and your ability to regulate metabolism and the ability to make healthy choices in general.
Michael A. Grandner
A participant’s level of attendance at group intervention sessions, the proportion of days they consumed between 85 and 115% of their recommended daily caloric intake, and the amount of time they spent engaging in moderate to strenuous physical activity each day were all used to determine their level of adherence to the weight loss program.
At the beginning of the study, six months into it, and a year afterwards, participants’ average sleep health score was 4.5 out of 6. At the beginning of the trial, at 6 months, and at 12 months, participants self-reported their daily calorie consumption using a smartphone app, and researchers monitored their physical activity using a waist-worn accelerometer for one week at a time.
The researchers discovered that better sleep health was linked to higher rates of attendance at group interval sessions, adherence to caloric intake goals, and improvement in time spent engaging in moderate-vigorous physical activity after adjusting the sleep health scores for age, gender, race, and whether or not a partner shared the bed. They found:
- Participants attended 79% of group sessions in the first six months and 62% of group sessions in the second six months.
- Participants met their daily caloric intake goals on 36% of days in the first six months and 21% in the second six months.
- Participants increased their total daily time spent in moderate-vigorous activity by 8.7 minutes in the first six months, however, their total time spent decreased by 3.7 minutes in the second six months.
“The decrease in group session attendance, caloric intake and in time spent in moderate-vigorous activity in the second six months was expected,” Kline said. “As one continues in a long-term behavioral weight loss intervention, it’s normal for the adherence to weight loss behaviors to decrease,” he said.
Furthermore, although there was a relationship between improved sleep health scores and an increase in physical activity, it was not statistically significant, so researchers cannot completely rule out the possibility that the outcomes were the result of chance.
“We had hypothesized that sleep would be associated with lifestyle modification; however, we didn’t expect to see an association between sleep health and all three of our measures of lifestyle modification,” he said. “Although we did not intervene on sleep health in this study, these results suggest that optimizing sleep may lead to better lifestyle modification adherence.”
The study’s drawbacks include the lack of an intervention to aid participants in improving their sleep, the fact that the study sample was not selected based on participant characteristics related to sleep health, and the fact that the entire sample population had reasonably good sleep health at baseline. Uncertainty exists regarding the generalizability of these findings to other diverse groups because the sample was largely white and female.
“One question of interest for future research is whether we can increase adherence to lifestyle modifications and, ultimately, increase weight loss if we improve a person’s sleep health,” Kline said.
A second question for the researchers is how such an intervention would be timed to improve sleep.
“It remains unclear whether it would be best to optimize sleep prior to rather than during attempted weight loss. In other words, should clinicians tell their patients to focus on getting better and more regular sleep before they begin to attempt weight loss, or should they try to improve their sleep while at the same time modifying their diet and activity levels?” Kline said.
Improving one’s sleep health is something everyone can do to improve their cardiovascular health and is a key component of the American Heart Association’s Life’s Essential 8. In 2022, sleep was added as the eighth element of good cardiovascular health, joining a healthy diet, regular exercise, quitting smoking, sleeping enough to maintain a healthy weight, and managing blood pressure, sugar, and cholesterol levels.
Cardiovascular disease claims more lives each year in the U.S. than all forms of cancer and chronic lower respiratory disease combined, according to the 2023 Statistical Update from the American Heart Association.
“There are over 100 studies linking sleep to weight gain and obesity, but this was a great example showing how sleep isn’t just tied to weight itself, it’s tied to the things we’re doing to help manage our own weight. This could be because sleep impacts the things that drive hunger and cravings, your metabolism and your ability to regulate metabolism and the ability to make healthy choices in general,” said Michael A. Grandner, Ph.D., MTR. Grandner is director of the Sleep and Heath Research Program at the University of Arizona, director of the Behavioral Sleep Medicine Clinic at the Banner-University Medical Center in Tucson, Arizona, and was a co-author of the Association’s Life’s Essential 8 cardiovascular health score. “Studies like this really go to show that all of these things are connected, and sometimes sleep is the thing that we can start taking control over that can help open doors to other avenues of health.”
