- Researchers say poor sleeping patterns can lead to weight gain and an increase in body mass index.
- They say the extra weight can lead to health issues such as high blood pressure, type 2 diabetes, and coronary artery disease.
- Researchers say caffeine and alcohol intake, as well as impulsive behaviors, can result in poor sleep.
- They recommend people set a regular bedtime and wake-up time, and make sure their bedroom is primarily for sleep.
Not getting enough sleep or having inconsistent sleeping patterns is associated with a higher body mass index (BMI).
Researchers in a studyTrusted Source published in the journal JAMA Internal Medicine used Fitbit wearable technology to collect sleep data from more than 120,000 people over a 2-year period.
“We examined the hypothesis that shorter sleep duration (hours slept at night) and greater day-to-day variability of sleep duration (standard deviation of hours slept at night) are associated with increased body mass index (BMI),” the study authors wrote.
They found that those in the study with a BMI over 30 (what’s considered the obesity rangeTrusted Source) had slightly shorter sleep durations and more variability in their sleep.
“These findings provide further support to the notion that sleep patterns are associated with weight management and overall health. The findings also support the potential value of including both sleep duration and individual sleep patterns when studying sleep-related health outcomes,” the researchers wrote.
This isn’t the first study to suggest a link between poor sleep and weight gain, but the authors argue the use of wearable technology like Fitbits gives researchers the opportunity to accurately track participants discreetly, without relying on memory of the participants’ for data.
“Most population-level sleep data are limited by recall bias, cross-sectional nature, and lack of detail regarding sleep habits over months to years. The recent increased uptake of wearable sensors (also known as activity trackers) has made such longitudinal data increasingly obtainable with digital devices that offer unobtrusive monitoring of multiple health parameters, including sleep,” the researchers wrote.
Experts say the findings of the study aren’t surprising.
“That has been known previously that short or long sleepers have higher BMI,” Dr. Kimberly A. Hardin, the director of the Sleep Medicine Fellowship Program at the University of California Davis, told Healthline.
“Poor sleep is causing the increased BMI. Poor sleep results in qualitative and quantitative sleep deprivation. The [consequences] are daytime sleepiness and poor productivity,” she said.
“Lack of energy and sleepiness or fatigue are often combated by caffeine and sugar, leading to weight gain and less exercise,” Hardin added.
How much sleep do you need?
Among the 120,522 participants involved in the study, the mean sleep duration was 6 hours and 47 minutes a night. Experts say this falls short of the optimal amount of sleep that’s recommended.
“In general, you want to get at least 7.5 hours of sleep on a regular basis if you can,” Dr. Rafael Pelayo, a sleep specialist at Stanford Health Care in California, told Healthline.
“A real clue whether you’re getting enough sleep or not is based on what you do on weekends. If somebody is sleeping in on a weekend routinely… and they’re trying to catch up on sleep, obviously they’re sleep-deprived during the week,” he said.
The number of hours of necessary sleep can vary based on age.
“For most adults, 7 to 8 hours is optimal, while 9 hours is required for adolescents, 10 hours for middle schoolers, 11 hours for elementary schoolers, 12 hours for toddlers (1 to 3 years old), 14 to 15 hours for infants, and 16 to 20 hours for neonates. These times are for a 24-hour period, so this includes daytime naps,” Dr. Richard Castriotta, FCCP, FAASM, sleep medicine specialist and pulmonologist at Keck School of Medicine of USC in California, told Healthline.
Castriotta said it’s not just the hours spent sleeping that can matter, but also the consistency of sleeping patterns.
“The healthiest sleep is to have a regular bedtime and wake-up time,” he explained. “Circadian rhythm disruption will cause problems, as anyone who’s ever experienced jet lag will confirm.”
“Also, shift work with a night-time work schedule is considered by the WHO as ‘probably carcinogenic’ with increased incidence of breast, prostate, and lung cancer, as well as obesity, diabetes, cardiovascular disease, stroke, and miscarriages,” Castriotta said.