So what’s all the fuss about changing the clocks and losing one hour of sleep once a year? It’s annoying, sure. But what’s the big deal? I mean, you’re a weekend warrior. One hour is nothing compared to what you put your body through on a typical Saturday night. Except you’ve noticed something. A hard weekend, a late night, a stretch of poor sleep, and your blood sugar numbers are off for a day or two afterward. You thought it was something you ate. It wasn’t random. Sleep and blood sugar control are more tightly connected than most of us want to admit.
What daylight saving time does, twice a year, is run that experiment on the entire population at once. And what it reveals is something you have already been living throughout the year without fully naming it.
I don’t love that connection any more than you do. But facts are facts.
In this article, I want to explore what the daylight saving time experiment reveals about sleep loss, blood sugar control, and cardiovascular risk. Then we’ll look at some practical steps that we both need to take all year long, not just in March.
The Research: Daylight Saving Time Is a Real Health Event
The spring clock change is not just an inconvenience. Studies have tracked it as a trigger for measurable health events.
The American Academy of Sleep Medicine reviewed the accumulated evidence and issued a formal position statement in 2020. The statement, authored by Rishi and colleagues and published in the Journal of Clinical Sleep Medicine, concluded that the spring transition carries significant public health and safety risks, including increased rates of adverse cardiovascular events, mood disorders, and motor vehicle crashes.
On the cardiovascular side, a review published in Frontiers in Medicine by Föh and colleagues at the University Hospital Schleswig-Holstein found that medical research has linked seasonal clock changes to increased rates of stroke, myocardial infarction, depressive episodes and even inflammatory bowel conditions. That is a notable cluster of risks from a single hour of lost sleep.
A study from Chudow and colleagues at Montefiore Medical Center, Albert Einstein College of Medicine, published in Sleep Medicine, looked specifically at atrial fibrillation admissions. They found a significant spike in AF hospital admissions in the days after the spring clock change, especially in women. Atrial fibrillation matters here because it dramatically raises stroke risk and is closely tied to autonomic nervous system dysregulation, which is the same pathway that disrupts blood sugar control.
A more recent large study from Rymer and colleagues at Duke University, published in JAMA Network Open in 2025 and covering over 168,000 patients across 1,124 hospitals, found no significant increase in acute myocardial infarction during the week of the spring or fall DST transition. That is important to note. The science here is not all pointing the same direction. The atrial fibrillation and stroke data remain more consistent than the heart attack data. But the biological disruption from the spring clock change is real, even if the downstream effect on heart attacks is smaller than early studies suggested.
Why the Spring Transition Hits Your Blood Sugar
Here is the thing about your body’s clock. It does not just govern when you feel tired. It governs when your pancreas releases insulin, how sensitively your muscle cells respond to glucose signals, and how your liver manages stored sugar overnight.
Stenvers and colleagues at Amsterdam University Medical Centers published a landmark review in Nature Reviews Endocrinology in 2019 titled “Circadian Clocks and Insulin Resistance.” They found that the circadian timing system coordinates glucose metabolism throughout the day. A central clock in the brain regulates whole-body insulin sensitivity and food intake. Peripheral clocks in your muscles, liver, gut, and pancreas fine-tune local responses. When these clocks fall out of sync with each other, or with your actual light-dark cycle, insulin resistance can follow.
That is exactly what happens in the spring when you lose an hour. Your body’s internal clock does not jump forward instantly. It takes days to recalibrate. In the meantime, you are eating breakfast when your biology still isn’t quite awake, and asking your pancreas to perform on a schedule it wasn’t prepared for.
Researchers have a name for this mismatch between your social schedule and your biological clock. They call it social jet lag. Anothaisintawee and colleagues at Mahidol University in Bangkok studied over 1,000 adults with prediabetes and published their findings in Chronobiology International in 2017. They found that a later sleep timing, a sign of circadian misalignment, was independently associated with higher hemoglobin A1c levels, even after accounting for body weight, sleep duration, and sleep quality.
In other words, when your body clock is out of sync with your schedule, your long-term blood sugar control suffers.
The spring clock change creates social jet lag on a population-wide scale. It points out what could be happening to you all the time if you’re not getting adequate sleep and staying on a regular schedule. Chronobiology shows that your body does indeed have a schedule, and insulin resistance increases when you deviate from it.
One Night of Poor Sleep Is Enough to Shift Your Insulin Sensitivity
You might think a single hour of lost sleep is too small to matter. The research says otherwise.
Donga and colleagues at Leiden University Medical Centre published a study in Diabetes Care in 2010 that looked at what happens to insulin sensitivity in people with type 1 diabetes after just one night of shortened sleep. Restricting sleep to four hours decreased peripheral insulin sensitivity by about 21 percent compared to a full night’s sleep. One night.
An earlier randomized controlled trial by González-Ortiz and colleagues, published in Diabetes, Nutrition and Metabolism in 2000, found that 24 hours of sleep deprivation significantly raised steady-state glucose concentrations in healthy subjects, indicating a clear drop in insulin sensitivity.
Both of these studies above were much more extreme than just a single hour of lost sleep. So if you lose just one hour, the likelihood of impact is very high, but the magnitude of the impact is not nearly as great as what is seen in these studies here.
The more sobering finding, though, comes from long-term data. Yaggi and colleagues at Yale University School of Medicine followed a cohort of men from the Massachusetts Male Aging Study for up to 17 years, tracking sleep duration against the development of type 2 diabetes. They published their results in Diabetes Care in 2006. Men who reported sleeping five hours or less per night were nearly twice as likely to develop diabetes over the follow-up period compared to those sleeping seven hours. Not twice as likely after years of eating poorly. Twice as likely from sleep alone. That is what chronic short sleep does when it compounds night after night, week after week.
Sleep Is Not Optional. It Is Part of Your Treatment Plan.
Here is the bigger message hiding inside the clock change story.
The spring DST transition is dramatic enough that researchers can measure it across entire hospital systems. But the same biology is at work every single week for millions of people. Every late Saturday night followed by an early Monday alarm is a smaller version of the same disruption. Researchers actually have a name for it: social jet lag. It is the chronic, low-grade mismatch between your biology and your schedule, and it quietly raises your A1c, month after month, without you ever connecting it to the nights you stayed up too late.
You have probably already noticed this in your own numbers. A rough night of sleep, and the next morning’s reading is higher than you expected. You thought it was something you ate. Or just one of those days. It was not random. It was your circadian rhythm telling you exactly what it needed, and not getting it.
So the takeaway from this article is not just “watch out in March.” It is this: sleep is a metabolic intervention. Protecting it every night, not just when the clocks move, is one of the most powerful things you can do for your blood sugar, your heart, and your long-term health.
Here is what that looks like in practice.
Treat your sleep window like an appointment you cannot miss.
Seven to eight hours is not a luxury. For someone managing blood sugar, it is a clinical necessity. Pick a consistent bedtime and wake time and hold to it seven days a week, including weekends. The weekend is when most people experience social jet lag, staying up late on Friday and Saturday and then wondering why Monday morning is so hard. See our article on making Monday morning easier.
Get morning light every day.
Within 30 minutes of waking up, get outside and expose your eyes to natural daylight. This is the most powerful signal your brain receives to anchor your circadian clock. It helps your body know when to be alert, when to secrete insulin efficiently, and when to wind down at night. Five to ten minutes, even on a cloudy morning, makes a real difference.
Eat on a consistent schedule.
Your pancreas, liver, and gut each have their own peripheral clocks that are partly entrained by meal timing. Eating at roughly the same times each day, especially a consistent breakfast, helps keep your peripheral clocks synchronized with your central brain clock. Skipping breakfast or pushing meals later throws off the timing of insulin secretion, even when your food choices are good.
Anchor your mornings with nutrients, not just caffeine.
What you eat first thing matters more than most people realize. A high-fiber, low-glycemic start to the day gives your body a steady glucose curve to work with while your circadian system calibrates in the morning. Many people get by without eating breakfast until mid-morning. And if that’s your usual schedule, then your body gets used to it.
Other people need something to eat sooner. For those people, the high-fiber, low-glycemic start makes a lot of sense. We have found that banana berry smoothies, made with ½ cup of almonds per blender (for 3 adults), and especially with added flaxseed (1-2 Tbsp per person), meet that criteria very well. They do not cause a high blood spike in most people. B-Flax D is a very convenient way to get flax fiber and fortified nutrients into your breakfast smoothie.
Move after meals, every day.
A 10 to 15-minute walk after eating helps your muscles absorb glucose independently of insulin. It is one of the most reliably effective tools for flattening post-meal blood sugar spikes, and it works regardless of what time of year it is or how well your circadian rhythm is calibrated that particular week.
Around the spring clock change, give yourself extra margin.
In the three to four days before the spring transition, shift your bedtime 15 to 20 minutes earlier each night. Watch your glucose readings more closely for several days after the clocks move. Not with anxiety, but with attention. Your body is working harder during that window, and your monitor’s data will show it. Use it.
The clock change happens twice a year. Social jet lag happens every week. Monday morning happens every week. Your body is keeping score of it all, all the time. The question is whether you are paying attention.
A Hallelujah DIet Perspective
Activity and rest are built into our daily and weekly schedules. God knew what He was doing when He created us, even telling us that a day of rest was not optional but necessary. He put that rhythm into creation itself: light and dark, seasonal shifts, work and rest. The Sabbath principle is not just a religious idea. It is written into your very cells.
When you live in alignment with your design, your body functions better. So when the culture tells you that sleep is for the weak and that fewer hours means more productivity, you are not just making a lifestyle choice. You are fighting against your own biology. If you are carefully managing blood sugar, you will see it in your numbers. Disrupt your schedule repeatedly, week after week, and your A1c will reflect it.
Sleep is not a reward for a good day. It is a biological requirement for health. Protect it, and you are likely to find that not only is your physical body functioning better, but your mental clarity improves, your decisions get sharper, and a sense of balance returns to your whole life.
That is what it looks like to live the way you were designed to live. And that is worth shouting about. Hallelujah!
References
1. Rishi MA et al. “Daylight saving time: an American Academy of Sleep Medicine position statement.” J Clin Sleep Med. 2020;16(10):1781-1784.
2. Föh B et al. “Seasonal Clock Changes Are Underappreciated Health Risks.” Front Med (Lausanne). 2019;6:103.
3. Chudow JJ et al. “Changes in atrial fibrillation admissions following daylight saving time transitions.” Sleep Med. 2020;69:155-158.
4. Rymer JA et al. “Daylight Savings Time and Acute Myocardial Infarction.” JAMA Netw Open. 2025;8(9):e2530442.
5. Stenvers DJ et al. “Circadian clocks and insulin resistance.” Nat Rev Endocrinol. 2019;15(2):75-89.
6. Anothaisintawee T et al. “Later chronotype is associated with higher hemoglobin A1c in prediabetes patients.” Chronobiol Int. 2017;34(3):393-402.
7. Donga E et al. “Partial sleep restriction decreases insulin sensitivity in type 1 diabetes.” Diabetes Care. 2010;33(7):1573-7.
8. González-Ortiz M et al. “Effect of sleep deprivation on insulin sensitivity and cortisol concentration in healthy subjects.” Diabetes Nutr Metab. 2000;13(2):80-3.
9. Yaggi HK, Araujo AB, McKinlay JB. “Sleep duration as a risk factor for the development of type 2 diabetes.” Diabetes Care. 2006;29(3):657-61.
