How many minutes of lost sleep it takes to gain weight, according to scientists

Losing as little as an extra hour of slumber each night is a realistic pattern of chronic mild sleep restriction.

Scientists tracked 95 adults who typically sleep between seven and eight hours a night over two separate six-week phases.

In phase one, respondents were asked to follow their normal sleep schedule, whereas in phase two, they were asked to push their bedtime back by approximately 90 minutes.

During the latter restrictive phase, participants had their body weight, waist measurements and body composition measured.

Findings show they gained an average of 1lb – which equates to roughly half a kilogram – over the six weeks they were monitored.

Although the weight gain was only modest, researchers noted it occurred in just six weeks, which means it could compound significantly over a year of lost sleep.

Sleep deprivation also appeared to hinder physical ability, leading to an increase in sedentary time – 17 minutes a day on average. This climbed to approximately 30 minutes a day among men and post-menopausal women.

Because people generally consume more food when sleep-deprived, leading scientists to believe it's reduced activity combined with heightened food intake that is driving the weight gain.

They stress that the findings do not prove sleep loss directly causes weight gain in every individual, however.

Diet, genetics, stress and activity levels all play a role too.

Nevetheless, the researchers say the results reinforce that sleep hygiene deserves the same attention as diet and exercise in supporting long-term metabolic and heart health.