You wake up in the middle of the night with a racing heart, lightheadedness or an unexplained craving, blaming it on stress or screens. Far fewer think about their blood sugar. Yet the US Centers for Disease Control recommends at least seven hours of sleep per night, even though an estimated 50 to 70 million Americans suffer from a sleep disorder. The way we eat could well be involved.
A large analysis carried out by nutrition researcher Raedeh Basiri, based on 39,794 adults followed in the NHANES survey between 2007 and 2020, shows that sleep and blood sugar are closely linked, in people with or without diabetes. Glycemic status, macronutrient profile and difficulty sleeping all evolve together. And in some cases, very well-controlled diabetes even seems to be accompanied by more complicated nights.
Sleep, blood sugar and diabetes: a complicated circle
The French data first remind us that sleeping too little disrupts glucose metabolism. According to the French Federation of Diabetics, reduced sleep causes a dysregulation of carbohydrate metabolism with a “50% drop in insulin action” and “30% drop in the quantity of insulin produced”. This terrain promotes prediabetes, type 2 diabetes, excess weight and derails circadian rhythms, this internal clock which synchronizes wakefulness, hunger and hormonal secretions.
The opposite is just as true. In Raedeh Basiri’s analysis, 38.49% of adults had prediabetes or diabetes. People with diabetes most often reported sleep disorders: 37.74% reported difficulty sleeping and 9.56% had a diagnosed sleep disorder, with more short sleep (less than 7 hours) but also prolonged sleep (more than 9 hours) than people with normoglycemia. In practice, variations in blood sugar, nocturnal hypoglycemia, frequent urges to urinate or pain linked to diabetes fragment sleep and maintain this vicious circle.
What the major study on sleep and blood sugar reveals
By modeling the data, the George Mason University team observed that, compared to adults with normoglycemia, those with diabetes were 37% more likely to report sleep problems, 61% more likely to have a diagnosed sleep disorder, 21% more likely to sleep too little, and 37% more likely to sleep too long. Prediabetes appeared to be more modestly associated with sleep complaints. Striking point in people with diabetes: control considered very strict, with an HbA1c below 6.5%, was linked to a 27% additional risk of sleep difficulties compared to an HbA1c between 6.5 and 9%. The authors mention a possible role of nocturnal hypoglycemia, therapeutic burden and an impact on mood.
The study also looked at the distribution of macronutrients. A diet low in protein appears to be the most unfavorable for sleep. In people with diabetes, it was associated with more than double the risk of diagnosed sleep disorder (OR 2.43). In those with prediabetes, it doubled the risk of prolonged sleep (OR 2.04). In adults with normoglycemia, it increased the risk of short sleep by 31% and that of too long sleep by 72%. When this low protein intake was combined with excess fat, sleep problems were further accentuated, while a low-carb high-fat profile with sufficient protein reduced the risk of too little sleep by 22% in diabetics and by 15% in people without diabetes.
Evening diet, blood glucose variability and sleep quality
Everything then comes down to diet, hormones and nights. A very fatty and low-protein dinner promotes glycemic peaks then falls, alters the secretion of leptin and ghrelin, increases nocturnal cravings and glycemic variability. Conversely, a sufficient intake of quality proteins provides tryptophan, a precursor of serotonin and melatonin, and seems associated with fewer nighttime awakenings in several clinical trials. The quality of carbohydrates also matters: complex carbohydrates stabilize blood sugar levels better than refined sugars, which are more likely to disrupt sleep.
Without replacing medical advice, some benchmarks emerge from this work for the evening meal:
- Provide a portion of good quality proteins (fish, eggs, legumes, dairy products) rather than reducing them too much;
- Favor complex carbohydrates in moderate quantities (vegetables, whole grains) and limit very sweet desserts;
- Avoid dinners with excess fat and very little protein, especially repeatedly;
- Keep regular bedtimes, monitoring the impact on blood sugar if diabetes is present.
For people living with diabetes or prediabetes, these results encourage discussing a stable nighttime blood sugar goal with the healthcare team, rather than aiming for the lowest possible value at all costs. The use of continuous glucose sensors helps identify silent hypoglycemia and links between evening meals and nocturnal awakenings. In the background, a balanced diet, adapted to everyone, appears to be a concrete lever to soothe the nights while supporting glycemic control.