Chennai, July 9 -- Highlights:
* Sleeping about 80 minutes less each night may be linked to gradual weight gain over time
* Not getting enough sleep may increase sedentary time, reducing daily physical //activity
* Getting the recommended 7-9 hours of sleep may help support healthy weight and overall metabolic health
Sleeping about 80 minutes less each night for six weeks was associated with modest weight gain and spending more time being inactive in a randomized crossover clinical trial involving 95 healthy adults . Participants gained an average of nearly 1 pound (0.45 kg) and spent more time in sedentary activities, suggesting that chronic short sleep may gradually affect body weight and metabolic health when it becomes a long-term habit ( ref1 ). Adequate sleep is increasingly recognized as an important part of maintaining overall health, alongside a balanced diet and regular physical activity. However, many adults regularly sleep less than the recommended amount because of work, family responsibilities, or lifestyle habits. To understand whether this common pattern of mild sleep loss could influence body weight and daily activity, researchers evaluated the effects of modest sleep restriction under controlled conditions.
The trial included 95 healthy adults who normally slept 7-8 hours each night . Participants completed two separate six-week phases in random order. During one phase, they maintained their usual sleep schedule. During the other, they delayed their bedtime by about 90 minutes , reducing their actual sleep by approximately 80 minutes each night . Throughout both phases, researchers monitored sleep and physical activity using wrist-worn devices and measured body weight, waist circumference, body composition, and fasting levels of hormones involved in appetite regulation ( ref1 ).
How Was Short Sleep Evaluated?
The study used a randomized crossover design , allowing every participant to complete both the normal-sleep and reduced-sleep phases. This approach enabled each participant to serve as their own comparison, helping minimize differences related to age, lifestyle, diet, and other personal factors.
Researchers objectively tracked sleep duration and physical activity using wearable monitors instead of relying only on participants' self-reported sleep habits. This provided a more accurate assessment of how mild but prolonged sleep restriction affected daily behavior and body measurements.
What Happened When Participants Slept Less?
During the six-week sleep-restriction phase, participants gained an average of nearly 1 pound compared with the normal-sleep phase. Although the increase was modest, the researchers noted that gradual weight gain over a relatively short period could become more meaningful if similar sleep habits persist over months or years. However, the study did not directly evaluate long-term weight changes ( ref1 ).
Participants also spent more time being sedentary. On average, daily sedentary time increased by about 17 minutes , while men and postmenopausal women showed increases of nearly 30 minutes per day . Even after accounting for the longer time participants were awake, they still spent a greater proportion of that extra time being inactive rather than physically active ( ref1 ).
These findings suggest that chronic mild sleep loss may influence body weight not only through changes in appetite but also by reducing daily movement , an important factor for maintaining metabolic health.
How Can Short Sleep Affect Body Weight?
Researchers believe that chronic short sleep may influence body weight through several biological and behavioral pathways. Previous research has shown that insufficient sleep can affect hormones that regulate hunger and fullness, which may increase calorie intake in some people. The current findings also suggest that reduced physical activity could contribute to gradual weight gain, as participants spent more time being sedentary during the sleep-restriction phase ( ref1 ).
The researchers also referred to earlier analyses involving the same group of participants, which reported changes related to insulin resistance and increased inflammatory immune cells in the heart among individuals with elevated cardiometabolic risk. These observations suggest that inadequate sleep may affect several biological processes linked to long-term metabolic and cardiovascular health . However, further research is needed to better understand the mechanisms involved.
What Are the Limitations of the Findings?
The study has several strengths, including its randomized crossover design, objective monitoring of sleep and physical activity using wearable devices, and a six-week intervention that closely reflects the mild sleep restriction experienced by many adults in everyday life.
However, the findings should be interpreted with some caution. The study involved only 95 healthy adults , so the results may not apply to children, older adults with multiple medical conditions, or people with diagnosed sleep disorders. In addition, the intervention lasted only six weeks, meaning the researchers did not directly measure the long-term effects of chronic sleep restriction.
The researchers suggested that similar sleep patterns maintained over a longer period could lead to greater weight gain. However, this was an extrapolation based on the study findings and was not directly measured . Therefore, the results show an association under controlled conditions rather than proving that sleeping less inevitably causes obesity ( ref1 ).
Why Healthy Sleep Matters for Everyday Health
The findings highlight the importance of healthy sleep as part of an overall healthy lifestyle, alongside balanced nutrition and regular physical activity. While the average weight gain observed in this study was modest, regularly sleeping less than the recommended amount may gradually contribute to weight gain and reduced daily movement over time ( ref1 ).
Most adults are advised to get 7-9 hours of sleep each night. Maintaining consistent sleep habits may support healthy weight management, metabolic health, and overall well-being. Future research will help determine whether improving sleep duration can reverse these changes in people who routinely experience insufficient sleep.
medfaq
Reference:
* Prolonged Short Sleep and Its Effect on Body Weight and Composition. - (https://doi.org/10.7326/ANNALS-25-01660)
Source-Medindia