Faulty reasoning signals

• Confirmation Bias - 6.1% (89 hits)
• Anchoring Bias - 0%
• Availability Heuristic - 2.3% (34 hits)
• Representativeness Heuristic - 3.4% (50 hits)
• Hindsight Bias - 0%
• Overconfidence Bias - 9.5% (140 hits)
• Framing Effect - 3.2% (47 hits)
• Loss Aversion - 0%
• Status Quo Bias - 1.5% (22 hits)
• Sunk Cost Effect - 0%
• Optimism Bias - 1.3% (19 hits)
• Pessimism Bias - 3.1% (45 hits)

Article text

Missing just over 1 hour of sleep each night may lead to weight gain

A new study notes that adults who shortened their sleep for 6 weeks gained an average of 1 pound, suggesting that even mild, chronic sleep deprivation may contribute to gradual weight gain over time.

Additionally, sleep restriction increased sedentary behavior by an average of 17 more minutes per day, with men and postmenopausal women showing increases of nearly 30 minutes per day.

Previous analyses of the same participants found increased insulin resistance in women with elevated cardiometabolic risk and signs of heart inflammation following chronic mild sleep restriction.

The findings suggest prioritising adequate sleep, alongside a healthy dietary plan and regular physical activity, could help reduce the risk of weight gain, obesity, type 2 diabetes, and heart disease.

Previous research has linked severe sleep deprivation to increased appetite and overeating.

This is likely due to a variety of factors, including rising ghrelin levels, the hormone that stimulates hunger, and declining leptin levels, the hormone that signals fullness.

In an effort to balance work, family, and social commitments, it is not uncommon for adults to sacrifice sleep.

In adults, sleep deprivation typically describes getting less than the daily recommended 7 to 9 hours of sleep.

However, some studies investigating the link between insufficient sleep and obesity may involve unrealistic sleep scenarios, such as participants sleeping only 4 hours per night.

Additionally, many people are unable to tolerate sleep deprivation for more than a few days.

Thus, research focusing on a more common pattern of sleep restriction may provide a more realistic relationship between sleep deprivation, appetite, and potential weight gain.

Now, a new study suggests that regularly sleeping less than usual, even by just over an hour a night, could gradually contribute to weight gain and a more sedentary lifestyle.

The findings, published in Annals of Internal Medicine, found that participants following a shortened sleep schedule gained an average of 1 pound (lb), or approximately half a kilogram (kg), over the 6-week study period, and also spent significantly more time being sedentary compared with periods when they maintained their usual sleep routine.

Small sleep changes may add up over time

The research team recruited 95 adults who typically slept between 7 to 8 hours each night.

Participants then completed two separate 6-week phases.

During one phase, they were instructed to delay their usual bedtime by approximately 90 minutes, with participants experiencing an average sleep reduction of 78.4 minutes.

During the other phase, they maintained their normal sleep schedule.

Throughout both phases, participants wore wrist monitors that tracked sleep and physical activity.

The researchers also measured changes in body weight, waist circumference, body composition, and fasting hormone levels associated with appetite regulation.

During the sleep restriction phase, researchers found that participants gained an average of 1 lb over 6 weeks.

While the weight gain was modest, the researchers note that it occurred over just 6 weeks.

As the study was designed to mimic sleep patterns many adults experience chronically, it is important to consider the potential long-standing effects.

When extrapolated over a full year, losing roughly 80 minutes of sleep per night could result in clinically meaningful long-term weight gain.

Study author Marie-Pierre St-Onge, PhD, CCSH, FAHA, a nutrition scientist and founding director of the Center of Excellence for Sleep and Circadian Research at Columbia University, emphasized to Medical News Today that “the main takeaway is that sustaining a reduction in sleep, to a duration that is often observed in the general population, leads to weight gain and increases in waist circumference.”

Less sleep also meant less movement

Notably, the study also found that participants became less physically active when they slept less.

Sedentary time also increased by an average of 17 minutes per day during the sleep-restriction phase.

Among males and postmenopausal females, inactivity rose by nearly 30 minutes each day.

The increase in sedentary behavior remained even after researchers accounted for the fact that participants simply had more waking hours available.

This suggests that inadequate sleep may influence not only how long people are awake but also how they choose, or feel able, to spend that extra time.

This is particularly important as not only can sleep deprivation negatively impact health, but individuals who spend more time being inactive are also at higher risk of chronic health problems.

“Weight gain occurs through an imbalance in energy expenditure and energy intake favoring greater intake relative to expenditure (or conversely low expenditure relative to intake),” St-Onge explained to MNT.

“In this study, we noted greater time spent sedentary when participants were asked to reduce their sleep duration.

We have shown in previous studies that participants eat more when sleep is restricted.

I think both come into play when it comes to insufficient sleep,” she added.

“We found 17 min more time spent sedentary in the context of sleep restriction compared to adequate sleep.

This is important because public health messages to reduce the risk of chronic disease include reducing sedentary time.

Our participants were screened to be relatively sedentary/non-active.

Therefore, the influence of insufficient sleep worsens an already poor lifestyle factor,” the researcher told us.

Could poor sleep affect more than body weight?

The findings build on earlier research involving the same group of participants.

In previous analyses, females with elevated cardiometabolic risk who experienced mild sleep restriction developed increased insulin resistance, which can raise the risk of type 2 diabetes.

The effect appeared to be particularly pronounced among postmenopausal females.

This aligns with other research suggesting that inadequate sleep can both increase the risk of developing type 2 diabetes and worsen the condition in those already living with type 2 diabetes.

“In a previous publication, we showed that glucose tolerance and insulin sensitivity are reduced due to insufficient sleep.

Basically, more insulin needs to be secreted to achieve normal glucose levels in the context of insufficient sleep,” St-Onge told us.

“Over time, this can lead to prediabetes and type 2 diabetes, if not corrected.

These findings were obtained independent of changes.

Given that weight gain contributes to the risk of insulin resistance, the current findings further provide evidence for an adverse health effect of insufficient sleep on insulin resistance and inflammation,” she added.

In another related investigation, the researchers found evidence of increased inflammatory cells within the heart following prolonged mild sleep restriction in participants already at higher cardiovascular risk.

Previous research has noted a complex two-way relationship between sleep and heart health, noting that sleep deprivation is associated with the release of stress hormones and markers of inflammation, which can increase the risk of cardiovascular disease.

Together, these findings suggest that chronic sleep loss may influence several biological processes linked to metabolic and cardiovascular health.

More research is still necessary

Although the findings add to evidence about the relationship between sleep and weight, the researchers caution that the study does not prove that sleep loss directly causes weight gain in every individual.

Multiple factors, such as dietary plans, genetics, stress, and physical activity, also play important roles in body weight and overall health.

However, the results do emphasize that adequate sleep plays an important role in health, and that sleep hygiene should be considered alongside nutrition and exercise as part of a healthy lifestyle.

How to improve sleep hygiene to achieve 7 to 9 hours of sleep?

“Spending more time in bed is essential to achieving longer sleep but this is not beneficial if the person is lying awake in bed, trying to sleep,” St-Onge pointed out.

According to her, “recommendations must be personalized based on a person’s social and personal obligations.”

“For example, does the person have a set wake time to be able to get to work on time?

If so, counting backwards to a possible bedtime is more relevant,” she advised.

“Are there some evening/night time activities that can be reduced in duration or re-allocated to another period of the day to allow for an earlier bedtime?

And it’s probably better to start with incremental increases in time in bed duration to ensure that you can fall asleep well and gradually adjust to the new schedule.”

– Marie-Pierre St-Onge, PhD, CCSH, FAHA

“Also, reduce/eliminate things that interfere with your ability to fall asleep like eating close to bedtime, consuming caffeine too late in the day, doing stressful activities,” the researcher suggested.

While losing roughly 80 minutes of sleep each night may not seem significant, the findings suggest that even modest, long-term sleep restriction could gradually influence body weight and daily activity levels.

For many adults, prioritising consistent, sufficient sleep may be another important step toward supporting long-term metabolic and cardiovascular health.

Future studies will examine whether improving sleep in people who routinely get too little rest can help reduce the risk of obesity, type 2 diabetes, heart disease, and other chronic conditions.