4 min readNew DelhiMar 15, 2026 06:00 AM IST
Many people believe that blood sugar rises only after eating sugary or high-carbohydrate foods. However, a Canadian naturopathic doctor recently highlighted that several everyday habits can increase blood glucose levels, even when you have not eaten anything.
Dr Rachel Vong recently shared on social media that certain lifestyle factors, such as lack of sleep, stress, skipping meals, and even drinking coffee first thing in the morning, can cause unexpected spikes in blood sugar levels. To understand in detail how these factors affect the body, we reached out to Dr Chirag Tandon, Director – Internal Medicine, ShardaCare-Healthcity, who explained the science behind these surprising triggers.
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.
1. Not getting enough sleep
Sleep deprivation leaves the body insulin resistant, making glucose stay longer in the blood (Image: Freepik)
Poor sleep can directly affect how the body regulates glucose. According to Dr Tandon, sleeping for less than six hours a night can raise fasting blood sugar levels in the morning — even if a person has not eaten anything.
“Sleep deprivation leaves the body insulin resistant and therefore glucose stays longer in the blood,” he explains.
It also raises cortisol levels, which signal the liver to release more glucose into the bloodstream. In addition, the body naturally experiences a morning rise in blood sugar due to hormonal changes — known as the Dawn Effect — and poor sleep can make this spike stronger.
“To ensure consistent control of blood glucose, particularly in diabetic individuals, it is important to get a good quality sleep of at least 7-8 hours.”
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2. Stress
Stress can trigger a rise in blood sugar even without food intake. When the body is under stress, it releases hormones such as cortisol and adrenaline, which prepare the body for a “fight-or-flight” response. “These stress hormones cause the liver to empty the stored glucose into the bloodstream to provide quick energy,” Dr Tandon tells indianexpress.com.
Chronic stress can also increase insulin resistance over time. Additionally, stress may indirectly affect blood sugar by disrupting sleep patterns or reducing physical activity.
Practices such as regular exercise, meditation, relaxation techniques, and good sleep habits can help manage stress and stabilise glucose levels.
3. Skipping meals or prolonged fasting
When the gap between meals gets long, it can cause the body to generate stored sugar, leading to a “rebound spike” (Image: Freepik)
While intermittent fasting is popular for weight management, it may not suit everyone. In some individuals, especially those with hormonal issues or existing metabolic problems, long gaps between meals can cause blood sugar fluctuations.
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When the body goes for long periods without food, the liver may start releasing stored glucose to maintain energy levels. This can sometimes lead to a rebound spike in blood sugar.
In people taking diabetes medications, skipping meals may also increase the risk of Hypoglycemia.
Because people respond differently to fasting, it is advised to follow such eating patterns only with medical guidance, particularly for individuals with diabetes or other health conditions.
4. Having coffee for breakfast
For many people, the day begins with a cup of coffee — often before eating anything. However, caffeine can influence blood sugar in certain individuals. Dr Tandon points out that caffeine can temporarily reduce the body’s sensitivity to insulin, making it harder for cells to absorb glucose from the bloodstream.
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It can also increase cortisol levels, which may cause the liver to release more glucose. If the coffee contains added sugar, syrups, or flavoured creamers, the blood sugar spike can be even greater.
“Moderate consumption of black coffee is considered to be not harmful; however, people who have diabetes have to pay special attention to the reaction of their body,” Dr Tandon concludes.
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.
