A new study from the University of Leeds revealed that people who have insufficient sleep or have poor sleeping patterns were more likely to have high body mass index (BMI) and increased risk of becoming overweight or obese. The study, published in the journal PLOS One, showed that shorter sleep could increase waist measurement by up to three centimeters. Additionally, people suffering from lack of sleep were noticeably heavier than those who have a good night's sleep.

Sleep duration and metabolic health

For the study, the researchers analyzed the sleep duration and key biological parameters of 1,615 adults.

The participants reported how long they slept and how much food they ate. The researchers also took blood samples from the participants and recorded each participant’s weight, waist circumference, and blood pressure.

Aside from having higher waist measurement and weight, participants who reported an average sleep of six hours had lower levels of HDL cholesterol in their blood. HDL cholesterol, or more commonly known as the “good” cholesterol, helps in the removal of “bad” fat in the blood. Lower levels of HDL cholesterol in the blood could lead to a higher amount of bad fat in circulation, increasing the risk of heart disease.

Previous studies suggest that people with poor sleeping habits were more likely to choose a less healthy diet.

However, the researchers were surprised when they found no link between sleep duration and poor dietary choices. The researchers noted that healthy sleep duration may differ from person to person. Based on the result of the current study, the researchers recommend that seven to nine hours of sleep is best for most adults. The negative impact of sleep on metabolic health during this study was more apparent in individuals reporting an average sleep of six hours.

The obesity epidemic

Obesity has become a heavy public health burden worldwide. Global incidence of obesity has doubled since 1980. Over 1.9 billion people aged 18 years and above are considered to be overweight. Of those, more than 600 million are obese.

In the United States, Centers for Disease Control and Prevention estimates that more than one-third of American adults are obese.

Meanwhile, the prevalence of childhood obesity in the US has remained fairly stable in the past year but is still considered to be too high. About 12.7 million children and adolescents are living with obesity in the US. Obesity is linked to heart disease, stroke, type 2 diabetes, and even cancer.