New Delhi: Think losing an hour or so of sleep every night isn’t a big deal? Science says otherwise. A new study has found that trimming just around 80 minutes of sleep each night – an amount many people sacrifice while binge-watching shows, scrolling through social media or catching up on work- may be enough to trigger measurable changes in the body within weeks. The findings add to growing evidence that chronic, mild sleep deprivation can quietly affect metabolism, physical activity and long-term health, even in otherwise healthy adults.
Even a small cut in your nightly sleep could lead to weight gain, a bigger waistline and a more sedentary lifestyle in just six weeks, researchers warn. Researchers at Columbia University have found that the habit can lead to measurable weight gain and reduced physical activity in as little as six weeks. The study, led by nutritional medicine researcher Faris Zuraikat at Columbia University Vagelos College of Physicians and Surgeons, suggests that even mild, chronic sleep loss – common among millions of working adults can quietly alter the body’s metabolism and daily behaviour, raising concerns about its long-term impact on health
What did the study find
The research focused on healthy adults who typically slept seven to eight hours per night. Participants were asked to reduce their sleep by roughly 80–90 minutes every night for six weeks, resulting in an average sleep duration of around 5.5 to 6 hours.
By the end of the study, researchers observed several notable changes:
- Participants gained an average of 0.45 kg (about 1 pound).
- Their waist circumference increased, suggesting greater abdominal fat accumulation.
- They spent more time being sedentary, despite technically having more waking hours available.
Perhaps the most surprising finding was that people did not use their extra waking time to be more active. Instead, they became less physically active and spent more time sitting or resting. Researchers noted that this behavioural shift may contribute to gradual weight gain and increased risk of chronic diseases over time.
Why does losing a little sleep have such a big impact
Most previous sleep-deprivation studies have examined extreme scenarios, where volunteers were allowed only four or five hours of sleep. However, this study looked at a much more common real-world pattern: slightly shorter sleep night after night.
According to the researchers, this form of chronic, mild sleep restriction affects a significant proportion of adults and may be more representative of modern lifestyles. Even though participants were awake longer, they experienced greater fatigue, making them less likely to move around or exercise during the day.
How lack of sleep affects the body
Sleep plays a vital role in regulating hormones that control appetite, metabolism and energy balance. When people consistently get too little sleep, several biological changes can occur:
- Hunger hormones become disrupted, increasing cravings for calorie-dense, sugary and fatty foods.
- Blood pressure may remain elevated for longer because the heart gets less recovery time during sleep.
- Inflammation levels can rise, increasing cardiovascular strain.
- The body’s ability to regulate blood sugar declines, raising the risk of insulin resistance and eventually Type 2 diabetes.
Previous research has also linked chronic sleep deprivation with poorer cognitive function, mood disturbances, impaired memory and a higher risk of heart disease.
The long-term health implications
Although the average weight gain observed over six weeks was relatively small, researchers say the cumulative effect could become meaningful if the habit continues for months.
If similar patterns persist throughout the year, the gradual increase in weight and waist circumference could raise the risk of obesity, metabolic disorders and cardiovascular disease. The findings highlight that even modest sleep loss, when repeated night after night, is not harmless.
How much sleep do adults actually need?
Health experts, including the US Centers for Disease Control and Prevention (CDC), recommend that most adults aim for at least seven hours of sleep every night for optimal physical and mental health. Consistently falling below this recommendation has been associated with a higher risk of obesity, diabetes, heart disease and other chronic conditions.
Simple ways to protect your sleep
Experts recommend the following habits to improve sleep quality and duration:
- Maintain a consistent bedtime and wake-up schedule—even on weekends.
- Limit caffeine, nicotine and alcohol close to bedtime.
- Avoid prolonged screen use before sleeping, as blue light can interfere with melatonin production.
- Keep the bedroom cool, dark and quiet.
- Exercise regularly, but avoid vigorous workouts immediately before bed.
The study serves as a reminder that sleep is not simply “downtime” – it is a biological necessity. Missing just around 80 minutes of sleep each night may seem insignificant in the moment, but over weeks and months, that seemingly small sacrifice can affect body weight, activity levels and overall health. In an era where late-night scrolling and packed schedules often come at the cost of sleep, the findings reinforce a simple but powerful message: protecting your sleep may be one of the easiest ways to protect your long-term health.
