4 min readNew DelhiJul 18, 2026 08:00 PM IST
Missing a few hours of sleep may leave you feeling groggy the next morning, but growing evidence suggests the effects extend far beyond fatigue. Research has increasingly linked even short-term sleep deprivation to changes in how the body processes glucose, raising concerns that just a couple of nights of inadequate sleep could temporarily reduce insulin sensitivity, a key risk factor for Type 2 diabetes.
A 2022 systematic review published in Cureus analysed multiple studies on sleep deprivation and insulin resistance and found a consistent association between insufficient sleep and impaired insulin sensitivity. The review suggests that sleeping less than the recommended seven hours per night may trigger inflammatory responses, hormonal changes, and disruptions to the body’s circadian rhythm, all of which can interfere with how insulin works. While the exact biological mechanisms are still being investigated, the findings reinforce the importance of adequate sleep as a pillar of metabolic health alongside diet and exercise.
So, can just two days of poor sleep make you insulin resistant? According to Dr (Major) Rajesh Bhardwaj, Consultant, Med First ENT Center, “The evidence is pretty strong that even two nights of restricted sleep can temporarily impair insulin sensitivity, but that does not mean a healthy person will suddenly develop diabetes.”
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.
He explains that controlled laboratory studies have found that sleeping too little for just one to three nights makes the body’s cells less responsive to insulin. As a result, the pancreas has to produce more insulin to keep blood sugar levels within the normal range.
“The good news,” he adds, “is that these changes are generally transient and reversible in healthy individuals.”
However, repeatedly experiencing these episodes over months or years can gradually increase the likelihood of developing prediabetes and Type 2 diabetes.
How does lack of sleep affect blood sugar?
According to Dr Bhardwaj, sleep deprivation disrupts several hormones and biological pathways responsible for maintaining healthy glucose levels.
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One of the biggest culprits is cortisol, the body’s primary stress hormone. “Sleep deprivation amplifies the body’s stress response, leading to higher cortisol levels. Cortisol raises blood glucose and decreases the responsiveness of cells to insulin.”
Sleep loss also activates the sympathetic nervous system, further reducing insulin’s effectiveness. At the same time, poor sleep disrupts the hormones that regulate hunger. “It lowers leptin—the hormone that signals fullness—and increases ghrelin, the hormone that stimulates hunger. This often results in cravings for sugary, high-calorie foods and overeating.”
Dr Bhardwaj says sleep deprivation also contributes to chronic low-grade inflammation and disrupts the body’s circadian rhythm, both of which impair normal insulin signalling and glucose metabolism.
Is catching up on sleep enough?
Dr Bhardwaj says occasional sleep loss is unlikely to cause lasting harm in otherwise healthy individuals. “Many of the short-term metabolic changes can be reversed with adequate recovery sleep.”
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The concern arises when insufficient sleep becomes a regular pattern. Repeated bouts of sleep deprivation can trigger recurring insulin resistance, hormonal imbalance, increased appetite and gradual weight gain. “Over time, these changes can increase the risk of prediabetes and Type 2 diabetes, particularly in people who are overweight, physically inactive or have a family history of diabetes,” he adds.
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.