Does Oversleeping Cause Weight Gain? How Much Sleep Is Too Much
By WellnessVigor · Updated October 10, 2026 · 7 min read
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We hear a lot about the dangers of too little sleep. But what about sleeping too much? If you regularly sleep 9, 10 or more hours and still feel tired, you might wonder whether it is affecting your weight.
Research shows that both very short and very long sleep are linked to weight gain. Here is what that means, why it happens, and how to find your sweet spot.
Quick answer
Long sleep is linked to weight gain, but it is usually not the direct cause. In a 6-year study, people sleeping 9 to 10 hours gained more weight than those sleeping 7 to 8 hours. Long sleep often goes with less daily activity, irregular schedules, depression, or a sleep disorder such as sleep apnea. Most adults do best with 7 to 9 hours. If you need much more and still feel tired, see a doctor.
In the Quebec Family Study, researchers followed 276 adults for 6 years. Compared with people who slept 7 to 8 hours a night:
- Short sleepers (5 to 6 hours) gained about 2 kg more and had a 27% higher risk of developing obesity.
- Long sleepers (9 to 10 hours) gained about 1.6 kg more and had a 21% higher risk of developing obesity.
This is an association, not proof that long sleep causes weight gain. But it shows the “sweet spot” for weight is in the middle.
Why long sleep is linked to weight gain
- Less time to move. More hours in bed can mean fewer hours of daily activity.
- Irregular schedules. Long weekend lie-ins shift your body clock, which affects appetite and blood sugar.
- Underlying health issues. Depression, an underactive thyroid and some medicines can cause both long sleep and weight gain.
- Poor-quality sleep. Sleep apnea fragments sleep, so people spend longer in bed but still feel exhausted. Weight gain makes sleep apnea worse, creating a cycle. See how weight loss affects snoring and sleep apnea.
How much sleep is too much?
Most adults need 7 to 9 hours. Teenagers, people recovering from illness and those catching up on lost sleep may need more for a while. Regularly needing more than 9 to 10 hours and still waking tired is worth checking with a doctor. You may also find our guide on why you wake up tired after 8 hours of sleep helpful.
Want a regular sleep routine that leaves you refreshed in 7 to 9 hours? The 14-Day Sleep Reset shows you how, step by step.
How to find your sleep sweet spot
- Set a fixed wake-up time, even on weekends.
- Get daylight within an hour of waking.
- Move during the day; a daily walk helps sleep quality. See walking for weight loss.
- Limit naps to 20 to 30 minutes. See does napping cause belly fat?
- Use our sleep cycle calculator to choose a bedtime that fits your wake time.
Tools that make waking up easier
A sunrise alarm clock gradually brightens your room before your alarm, which many people find a gentler way to wake at the same time every day.
BEST ALL-IN-ONE SUNRISE ALARM
Hatch Restore 2 Sunrise Alarm Clock
Combines a sunrise light, sound machine and wind-down routines in one bedside device, controlled through an app.
Pros
- Gentle sunrise wake-up
- Built-in sleep sounds
- Attractive design
Cons
- Some content needs a subscription
- Pricier than basic wake-up lights
BEST CLASSIC WAKE-UP LIGHT
Philips SmartSleep Wake-up Light
A well-known light alarm from Philips that simulates sunrise and sunset to help you wake and wind down naturally.
Pros
- Trusted brand
- No subscription
- Sunset mode for bedtime
Cons
- Basic design on some models
- Takes up bedside space
Keep reading
Frequently asked questions
Is sleeping 10 hours bad for weight?
Can oversleeping make you tired?
How many hours of sleep is best for weight loss?
Is it bad to sleep in on weekends?
Sources
This article is for general information only and is not medical advice. See our Medical Disclaimer.