Sleep — or lack thereof — might fuel weight gain in more ways than previously believed, a mounting body of research suggests. But while this new research does confirm the link between sleep and weight, the recent findings will surprise even specialists.
A study published recently claimed that the lack of sleep prompted cravings, undue snacking and overeating, as the body needs fat and sugar to combat the lack of energy from not having rested sufficiently.
However, new research from the United Kingdom seems to contradict these findings, at least partially. The study did find a link between weight and lack of sleep, as subjects who slept less were found to be heavier and have larger waists. The study couldn't, however, find a link between their lack of sleep and eating habits.
To acquire the data, researchers surveyed 1,615 adults about their eating habits and sleep patterns. The participants were also asked to provide blood samples and various variables were measured such as weight, height, waist circumference, blood pressure and sugar, cholesterol and thyroid activity.
The study makers were able to establish a relationship between the sleep patterns and weight, as those who slept about 5.9 hours per night, for instance, had an average waist circumference of 37.4 inches, while those who reported having about two more hours of sleep per night only had an average waist circumference of 35.8 inches.
After taking factors such as age, ethnicity and gender, among others, into account, the researchers concluded that participants benefited a 0.3 inch reduction in their waist circumference from every additional hour they sleep per night on a regular basis.
Having a longer night of sleep doesn't just affect weight, however. The researchers also found that people who enjoyed less sleep per night had lower rates of high-density lipoprotein (HDL), which is considered to be the desirable kind of cholesterol.
The lack of sleep was also seemingly linked to higher inflammation and blood sugar, as well as lower thyroid activity, but the statistics weren't significant enough to be conclusive in this respect.
Surprisingly, the researchers did not find a conclusive link between the lack of sleep and the quality of participants' diets, in spite of the previous research that suggests poor sleep results in less willpower and equally poor dietary choices.
These studies bring forward a number of possible reasons for their disparaging findings. According to a statement, it is possible that the sample wasn't big enough to detect every factor and relationship between sleep and diet. The scope of the study, in which participants were only tested and surveyed once, may also have contributed to the surprising findings.