Lack of sleep increases unhealthy belly fat

Fat abdominal belly

New research from the Mayo Clinic shows that lack of sufficient sleep combined with free access to food increases calorie consumption and consequently the accumulation of fat, particularly the unhealthy fat within the belly.

Results from a randomized controlled cross study led by Naima Covassin, Ph.D., a cardiovascular medicine researcher at the Mayo Clinic, show that lack of sufficient sleep led to a 9% increase in total abdominal fat area and ‘11% of the abdominal fat visceral area, compared with sleep control. Visceral fat is deposited deep within the abdomen around internal organs and is strongly linked to heart and metabolic diseases.

The results are published in Journal of the American College of Cardiologyand the study was funded by the National Heart, Lung and Blood Institute.

Lack of sufficient sleep is often a behavioral choice and this choice has become increasingly pervasive. More than a third of adults in the United States don’t get enough sleep routinely, in part due to shift work and the smart devices and social networks used during traditional sleep periods. Additionally, people tend to eat more during their longer waking hours without increasing physical activity.

“Our results show that reduced sleep, even in young, healthy and relatively thin subjects, is associated with an increase in calorie intake, a very small increase in weight and a significant increase in the accumulation of fat within the belly. “says Virend Somers, MD, Ph.D., Alice Sheets Marriott Professor of Cardiovascular Medicine and principal investigator of the study.

“Normally, fat is deposited preferentially subcutaneously or under the skin. However, inadequate sleep appears to redirect fat to the more dangerous visceral compartment. Importantly, although there was a decrease in calorie intake and weight during recovery sleep, visceral fat continued to increase. This suggests that inadequate sleep is a previously unrecognized trigger for visceral fat deposition and that recovery sleep, at least in the short term, does not reverse visceral fat accumulation. In the long term, these findings imply inadequate sleep as a contributor to the epidemics of obesity, cardiovascular and metabolic diseases, ”says Dr Somers.

The study cohort consisted of 12 healthy people who were not obese, each of whom spent two 21-day inpatient sessions. Participants were randomly assigned to the control group (normal sleep) or the limited sleep group during one session and the opposite during the next session, after a three-month washout period. Each group had access to free choice of food during the study. Researchers monitored and measured energy intake; energy expenditure; body weight; body composition; fat distribution, including visceral fat or fat within the belly; and biomarkers of circulating appetite.

The first four days were an acclimatization period. During this time, all participants were allowed nine hours in bed to sleep. For the next two weeks, the restricted sleep group was granted four hours of sleep, and the control group was maintained with nine hours. This was followed by three days and three nights of recovery with nine hours in bed for both groups.

Participants consumed more than 300 more calories per day during sleep restriction, consuming about 13% more protein and 17% more fat than in the acclimatization phase. This increase in consumption was highest in the first few days of sleep deprivation and then gradually decreased to initial levels during the recovery period. Energy expenditure has mostly remained the same all along.

“The accumulation of visceral fat was only detected by the CT scan and otherwise it would have been lost, especially since the weight gain was quite modest, only about half a pound,” says Dr. Covassin. “Weight measurements alone would be falsely reassuring in terms of the health consequences of inadequate sleep. The potential effects of repeated periods of inadequate sleep in terms of a progressive and cumulative increase in visceral fat over the course of several years are also worrying ”.

Dr Somers says behavioral interventions, such as increased exercise and healthy food choices, need to be considered for people who cannot easily avoid sleep disruption, such as shift workers. More studies are needed to determine how these findings in healthy young people relate to people at higher risk, such as those who are already obese or have metabolic syndrome or diabetes.

Reference: “Effects of Experimental Sleep Restriction on Energy Intake, Energy Expenditure, and Visceral Obesity” by Naima Covassin PhD, Prachi Singh PhD, Shelly K. McCrady-Spitzer MS, Erik K. St Louis MD, Andrew D Calvin MD, James A. Levine MD, PhD and Virend K. Somers MD, PhD, March 28, 2022, Journal of the American College of Cardiology.
DOI: 10.1016 / j.jacc.2022.01.038

Leave a Comment