Poor sleep can increase visceral fat, which causes heart disease and metabolism

Although there is evidence that sleep deficiency increases the risk of obesity, experimental evidence is limited. However, studies continue to show the importance of good sleep habits for maintaining a healthy body weight, but much remains to be learned when it comes to understanding the finer details of this relationship.

Researchers at Mayo Clinic, in the United States, shed new light on this topic by demonstrating how lack of sleep can increase levels of insidious visceral fat deep in the abdomen, leading to serious health risks.

A long line of published research has illuminated the connection between sleep deprivation and obesity and its related conditions. This includes showing how irregular sleep patterns can raise the risk of hypertension and other metabolic disorders and double the chance of heart disease. Similarly, studies have shown how extra sleep can lead to a calorie deficit and reduce the risk of obesity in newborns.

While scientific knowledge is accumulating in this area, Mayo Clinic researchers point out that no specific studies have been conducted on the distribution of body fat. His work, which was published in the Journal of the American College of Cardiology, focuses on the differences between subcutaneous fat, which is located under the skin that can be simply felt when a person is pinches the belly, and visceral fat, the invisible type deep in the abdomen that can surround the liver, intestines and other organs.

Visceral fat only accounts for about 10 percent of total body fat in most people, but when it accumulates to excessive levels, it can play a disproportionate role in adverse health outcomes. This is because it produces large amounts of chemicals related to a wide variety of conditions, including cardiovascular diseases such as heart attack and atherosclerosis, type 2 diabetes, liver failure, gastrointestinal disorders, cancer, and asthma.

Therefore, it is important to control visceral fat levels. As a result, the Mayo Clinic study was designed to explore how sleep can play a regulatory role. It involved 12 healthy people who were not obese and were placed in a normal group that slept nine hours a night or in a restricted group that slept only four hours per night for a period of two weeks. This came after certain times of acclimatization and others of normal sleep recovery, and then the groups exchanged sleep habits after a period of bleaching habits of three months.

Groups had free access to food at all times, and scientists tracked their energy intake, expenditure, body weight, appetite biomarkers, and fat distribution through CT scans. It was observed that volunteers consumed more than 300 extra calories per day during their periods of sleep restriction, while their energy expenditure remained the same. This led to small weight gains, but an 11 percent increase in visceral fat, the researchers said.

“The accumulation of visceral fat was only detected by computed tomography and otherwise it would have been overlooked, especially since the weight gain was quite modest, only about 450 grams, explained Naima Covassin, who led the study. Weight measures alone would be falsely reassuring in terms of the health consequences of inadequate sleep.”

The study was designed to replicate irregular sleep patterns that shift workers could endure, with periods of inadequate rest interspersed with normal rest periods. Importantly, scientists found that impacts on visceral fat seemed to persist beyond periods of insufficient sleep, even when body weight decreased, which could have cumulative effects if these sleep patterns take place over several years.

“Normally, fat is preferentially deposited subcutaneously or under the skin,” said Virend Somers, another principal investigator in the study. However, inadequate sleep seems to redirect fat to the most dangerous visceral compartment. Importantly, although during recovery sleep there was a decrease in calorie intake and weight, visceral fat continued to increase. This suggests that inadequate sleep is a previously unrecognized trigger for visceral fat deposition and that recovering sleep, at least in the short term, does not reverse visceral fat accumulation,” he concluded.

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